One of my favorite tech legends is that apparently Voyager 1 launched with a Viterbi encoder, even though there was no computer on Earth at the time fast enough to decode it. After a number of years Moore's Law caught up and they remotely switched over to Viterbi for more efficient transmissions.
> even though there was no computer on Earth at the time fast enough to decode it
I'm not sure what is meant by that. Not fast enough to decode in real time? There is/was no need to do that. The transmissions would have gone to tape in any case.
I called it a legend deliberately. One of the things I love about this anecdote is that it makes less sense the older and more experienced I get. It was told to me 12 years ago as a young, starry-eyed junior developer by my supervisor who had a PhD in RF research, while we were working on what we considered to be a world-changing wireless technology at a startup in San Francisco (it wasn't).
Who knows how many of the details I misinterpreted or am misremembering, or that he was. Where did he hear it originally? Maybe a grizzled old professor who worked directly on the project? Maybe a TA who made up the whole thing?
Whether true or not, it inspired me then as it does now to strive to be a better engineer, to think outside the box, to attempt hard things.
I continue sharing it hoping that one day Cunningham's Law will take effect and someone will share the correct details. But there's also a part of me that hopes that never happens.
When I read the earlier comment, seeing “tech legend” didn’t make me assume that the story would be false. Grandparent’s clarification was helpful for me.
TFA: >I will use a recording that was done back in 30 December 2015 with the Green Bank Telescope in the context of the Breakthrough Listen project.
That recording was made in 2015 on a modern radio telescope, it is not from a tape.
The GP has the details wrong though: when the Voyager design was finalized in the early 70s with the Viterbi encoder, there wasn’t enough computational power to decode the signal. By the time it launched in ‘77, there was enough and it launched with the Viterbi encoder enabled.
I wrote test firmware for a very early spread spectrum transceiver that used something close to Viterbi encoding. It consumed 220mA in receive mode and 60-120mA in transmit mode. I was told some of that was the RF amps and ADC but a lot of it was the decoder.
I don’t know how well it holds today but for some time it was known that running certain computations on existing hardware would take longer than waiting for new hardware and running when available.
My life archive is available to my heirs and successors as long as they know the LUKS password for any of the numerous storage devices I leave behind. It’s risky though — the passwords aren’t known to them yet and one logistical slip up means the disk may be unusable. That is, however, until some point in the future when they will have a computer powerful enough to just break the key and feast upon my cat photos, tax returns, and other exciting ephemera.
Similarly my encrypted internet traffic might be private today but if it’s being logged then it’s only a matter of time before it will be completely visible to the authorities. I probably average ~10Mbps of traffic which is ~50TB/year, or $100 of storage. You could cut that price by 10% if you blacklisted the Netflix traffic, and drop it to 1% if you whitelisted only the email and IM traffic.
If the contents of your computer is anything like the contents of most old people's attics, there is a good chance your descendants really don't want to go through all of it. They'll just chuck it in the trash without even opening it.
Turns out the next generation has their own life to worry about, and doesn't care much for their ancestors' stuff (unless it's money... they love money...).
Pretty much. Anecdotes about lives of elderly people are nice when you are sitting an evening with a glass of wine and plate of cheese. Otherwise who cares? Nothing is worse than trying to go through bunch of old faded photos where no one - even the owner - can identify who is actually in the picture.
I guess in our day and age we could write extensive meta data about where and when a picture was taken and who is in the picture, but I don't care to look through my own pictures, why would anyone else?
> Anecdotes about lives of elderly people are nice when you are sitting an evening with a glass of wine and plate of cheese. Otherwise who cares?
I could imagine a future where DRM and copyright and just the cold fear of ligation could change the recreational screentime for families from being primarily studio-produced content to being primarily ancestor-produced content.
I remember some book I read where the child was constantly hearing about his family's history. Dune, maybe? Maybe a Philip Dick book? Asimov? I'm getting old.
My experience is completely different. I've painstakingly scanned my family's old pictures, transcribed the letters they wrote when on holiday, and still have some school crafts made by my grandparents.
After the death of one of my great uncles who died childless I picked up his photo and music collection. And I discovered the grandfather of a friend of mine in one of his holiday pictures, turns out they used to be friends and we had no idea.
I know my carefully curated collections of stuff will be worth pretty much zero to anyone a I leave them to. They may be interested in the pictures. But that would be about it. My massive cd/dvd/bluray/games/books/coins collection that I have amassed and carefully cataloged. At best it will end up at goodwill/ebay or at worst in the trash.
People who can profit. And the idea of profit might be different in future.
That attic might contain a priceless vintage synthesizer, that encrypted drive might contain a priceless set of vintage unpublished club penguin screenshots that would make its AI approximation 0.03% more accurate. Etc.
But after enough time passes, lots of people do get interested in their ancestors. That's why DNA ancestry services are a big business - people get curious about where their unknown farther relatives came from. I guess there's just less mystery about people you actually knew.
Wow, perhaps I’m an exception to the norm, but this isn’t my experience at all. My family regularly sends interesting historical records of the lives of our ancestors. My great aunt composed a historical record of my great grandfather, who over his life built dozens of houses by his own hand. Even at university, I read a number of interesting historical letters and documents of the people who lived in the same dormitories in generations past.
I guess I may be ignoring all those documents that weren’t interesting enough to be remembered, but I imagine it’s hard to predict what will be interesting in the future. The fact that 99% of our lives are stored in computers vs paper would still vastly reduce the number of _interesting_ documents.
The key difference may be in the volume. Old pictures are more important to a family because there are so few of them. I only have one picture of my grandfather because it was taken when cameras were rarer than hen's teeth and 35mm film hadn't been invented yet. Now we have hundreds of thousands of pictures between the family members. Every vacation, every meal, every unimportant moment in time. I don't have time to look at my own pictures and I don't expect anyone else ever will.
Digital assets are a lot more perishable that physical ones. Cloud accounts will expire and be purged before anyone has the chance to retrieve them. Nobody will do "storage wars" with your pictures. Your local storage will fail or become incompatible with future tech before anyone has a chance to care about it.
We generate information at an ever increasing rate so whatever digital collections we have now will probably never be "dug up" by our descendants for a deeper look.
I'm trying to leave a "curated" collection with a few memories in such a way that it's immediately available to my family after I'm no longer around. Some moments in time that were important to my life, and had an influence on theirs.
Leave everything and let LLMs curate it on demand. "Show me pictures of my grandpa during the 2020 pandemic." "Show me pictures of my grandma's hobbies." "Find the most interesting pictures in this folder, not interesting historically but interesting action or visuals." "Make a montage of my cousins growing up." "Change my wallpaper every day to the most interesting family photo from that day of the year."
I agree with you. Right now I'm going through my grandfather's squadron records. Hoping to find the day that he crashed his motorcycle in Normandy to see what the CO thought about that. Apparently the other pilots were unhappy with him because they were banned from riding motorcycles after that.
Fpr what it's worth my grandfather recorded his memoirs recently and I am very grateful. He's led a very interesting life (much more so than my own!) which is the key component, really.
Oh man I’d love to have all the data of my parents, grandparents etc… even just having analogue records is interesting I’d love to know what kinds of hobbies they had like collecting digital music, art, books etc.
I think you and the previous commenter have very different opinions on what "all" means. Connecting to parents and grandparents by knowing what art they like is one thing, but, for example, I have hundreds of photos of random bills and documents that I need to remember for later. None of my descendents would ever want to read through that unless they were investigating my life like in a movie.
My most frequent type of data in my personal archive is screen shots of tumblr posts that my oldest child like to take when they were 12 and we all shared photo saving account.
I do snap bills and white boards to remember but not with the eager enthusiasm of the long since grown up child.
Because I have been interested in my dead relatives, and because I suspect somewhere down the line someone will be interested in my living ones, I have been trying to capture their lives in books I have created (real books — printed at Lulu.com).
I don't think this is universally true. Some people actually make an effort to sort the stuff of their grandparents in the attic and figure out what still has some (emotional) value. But it's probably a minority of people.
It's the volume problem - I'm happy to read handwritten pages of my mom's diary from the 1960s, but the reams of laser printer out put from her master's degree in 2000s? Not so much.
Only a matter of a really really _really_ long time and an absolutely unimaginably huge amount of energy.
All the energy released by converting all mass in the solar system into energy apparently gives a hard physical limit just above 2^225 elementary computations before you run out of gas so brute forcing a 256-bit symmetric key seems entirely unfeasible even if all of humanities resources were dedicated to the problem. The calculation is presented here https://security.stackexchange.com/questions/6141/amount-of-... . Waaay out of my field though so this calculation could be off or I could be misunderstanding somehow.
We will be able to crack today’s encryption algorithms in the future because we’ll find flaws in them. In other words, one day brute force won’t be necessary!
Have a look at this post, which illustrates this reality being true for hash functions (where similar principles as symmetric and asymmetric encryption apply). https://valerieaurora.org/hash.html
Notice Valerie specifically calls out, “Long semi-mathematical posts comparing the complexity of the attack to the number of protons in the universe”.
> We will be able to crack today’s encryption algorithms in the future because we’ll find flaws in them.
Big if.
We already knew how to design good and strong symmetric ciphers way back in the 1970s. One of the standard blocking blocks of modern symmetric cipher is called the Feistel network, which was used to create DES. Despite that it's the first widely used encryption standard, even today there's essentially no known flaw in its basic design. It was broken only because the key was artificially weakened to 56 bits. In the 1980s, cryptographers already knew 128 bit really should be the minimum security standard in spite of what NSA officially claimed. In the 1990s, when faster computers meant more overhead was acceptable, people agreed that symmetric ciphers should have an extra 256-bit option to protect them from any possible future breakthrough.
There are only two possible ways to break them, perhaps people will eventually find a flaw in Feistel network ciphers to enable classical attacks against all security levels, but it would require a groundbreaking mathematical breakthrough unimaginable today, so it's possible but unlikely. Another route is quantum computing. If it's possible to build a large quantum computer, all 128-bit ciphers will eventually be brute-forced by Glover's algorithm. On the other hand, 256-bit ciphers will still be immune (and people already put this defense in place long before post-quantum cryptography became a serious research topic).
Thus, if you want a future archeologist from the 23rd century to decrypt your data, only use 128-bit symmetric ciphers.
Placing no time constraints, my gut tells me it’s almost inevitable those breakthroughs will eventually come. Either in mathematics or quantum computing. Or both.
Namely I’d ask when not if. My opinion is that short of the one time pad, we won’t come up with provably unbreakable schemes.
The big assumption of cryptography is that, there exists some problems that are not provably unsolvable but difficult enough for almost any practical purposes. To engineers, no assumption can be more reasonable than that. Given unlimited time, it's a provable fact that any (brand new) processor with asynchronous input signal will malfunction due to metastability in digital circuits, it's also a provable fact that metastability is a fundamental flaw in all digital electronics - but computers still work because the MTBF can be made as large as necessary, longer than the lifetime of the Solar system if you really want to.
So the only problem here is, how long is the MTBF of today's building blocks of symmetric ciphers? If it's on the scale of 100 years or so, sure, everything is breakable if you're patient. If it's on the scale of 1000 years, well, breaking it is "only" a matter of time. But if it's on the scale of 10000 years, I don't believe it's relevant to the human civilization (as we know it) anymore - your standard may vary.
The problem is that computerized cryptography is a young subject, the best data we have so far is symmetric ciphers tend to be more secure than asymmetric ones. We know that Feistel networks have an excellent safety record and remain unbroken after 50 years. We also know that we can break almost all widely used asymmetric ciphers today with large quantum computers if we can build one, but we can't do the same to symmetric ones - even the ancient DES is unbreakable if it's redesigned to use 256-bit keys. So while nobody knows for sure, but most rational agents will certainly assign higher and higher confidence every year - until a breakthrough occurs.
> My opinion is that short of the one time pad, we won’t come up with provably unbreakable schemes.
Many mathematicians and some physicists may prefer a higher standard of security than "lowly" practical engineers. This is the main motivation behind quantum cryptography - rather than placing security on empirical observations, its slogan is that the security is placed on the laws of physics. Many have pointed that the this slogan is misleading: any practical form of quantum cryptography must exist in the engineering sense, and there will certainly be some forms of security flaws such as sensor imperfection or at least side channels... That being said, I certainly understand why it looks so attractive to many people if you're the kind of person who really worry about provability.
Agreed. My overall / initial point was that I can’t say the time to crack = the time to brute force and start talking about the age of the universe. Even if we had to wait 10,000 years for cryptanalysis to break AES, it’s a blink of an eye in sideral timescale.
> quantum cryptography
Quantum cryptography is helpful in detecting eavesdropping (due to the no clone theorem). Ie quantum cryptography is helpful in avoiding asymmetric encryption for key exchange when communicating with symmetric encryption. Eg BB84. And given asymmetric encryption is most vulnerable to quantum attacks (compared to symmetric), quantum cryptography improves today’s state of the art. BUT, I insist that none of this gives provably uncrackable schemes.
AND it might be that we never build such a scheme. After all we have Godel’s incompleteness theorem lying around.
> illustrates this reality being true for hash functions (where similar principles as symmetric and asymmetric encryption apply)
I think you're making a bit of confusion. hash functions are part of symmetric key cryptography, while asymmetric cryptography is public key cryptography that is very different from hash functions.
If, for example, someone has a computer capable of computing with a large number of qbits a lot of cryptography has less substantial break requirements.
Good idea - If you really do want to encrypt some data with hopes that it's recoverable by future archeologists, just use 128-bit symmetric ciphers (and remember not to use 256-bit ones). Hopefully Glover's algorithm can eventually brute-force it once large quantum computers are invented.
Definitely a threat at the nation-state actor level, the NSA are already providing guidance on how to use encryption today that is resistant to future advances in computation that would data recorded today to be decrypted later.
If hardware next year is X times better (e.g. even 1.01 or 1% better) than this year, and you have a computation that takes T time today, then next year, it'll take T/X time. So waiting will take 1 + T/X years if time unit is years. So the condition you want is 1+T/X < T. This equation has solutions for given X where X is an improvement, so as long as there is any improvement, it's always true waiting to start large enough computations will be faster.
Though even faster will be doing part of the computation now and then switching to new hardware later, so it's a false dichotomy.
> This equation has solutions for given X where X is an improvement, so as long as there is any improvement, it's always true waiting to start large enough computations will be faster.
Though this does assume that X is a constant, or at least bounded below by a constant. If hardware performance improved up to an asymptote, then there would still be nonzero improvement, but it might not be enough for waiting to ever be worth it.
As "If hardware next year is X times better (e.g. even 1.01 or 1% better) than this year" highlights X is a constant as a simplifying assumption, I'd have expected you to say "As this assumes that X is a constant" not "Though this does assume that X is a constant". So, I'm not sure what your disagreement is.
If your disagreement is that a constant is not appropriate here, consider the interpretation in this comparison of running a program on a slower computer A and then a faster computer B. There would be a constant difference in performance between these two computers, assuming they are in working order. So, taking the model with a single constant is appropriate for this example.
If you are saying the performance improvement is bounded below by a constant, I would ask you, what is the domain of this function? Time? So we would be talking about continuously moving a computation between different computers? The only line here is a best fit line, emergent data, so I don't understand how this could be a preferred way to talk about the situation (the alternate to an assumption), because this is suggesting the emergent structure with nice continuity features is a preferred fundamental understanding of the situation, but it's not.
Then, where you are talking about hardware performance improving up to a (assuming horizontal) asymptote. I guess this means "If hardware performance increase becomes marginal[1], there is a nonzero improvement." Or in other words, "If hardware performance increase is marginal, there is a marginal [performance] increase". Performance and improvement are both rates of change, so this is tautological.
Finally, you state that waiting for such a marginal near-zero performance increase isn't worth it. I think most people would agree this is obvious if said in simpler terms. However, this is still not disagreeing with me, because I never suggested waiting was worth it.
So, what's the disagreement?
[1] which is well-established not to be the case, so I don't think this is a relevant case to the interesting factoid about waiting to start computation
My apologies, I misinterpreted you as talking about waiting for many years (given a sufficiently large task) for performance to continue increasing, since this thread started talking about Moore's Law. I have no disagreement in the single-year case you were actually talking about.
> Though even faster will be doing part of the computation now and then switching to new hardware later
Not necessairly. This still costs:
• Programmer/development time to implement save/restore/transfer
• Time on new hardware, bottlenecked by old hardware, restoring a partial computation from old disks or networks
You're not going to waste time restoring partial calculations for anything from an Amiga cluster for time saving purpouses. Additionally, this scheme ties up hardware that then can't be used for "cost effective to finish on current hardware" calculations.
I wonder if this same law applies to distance satellites like Voyager get away from earth. Like we sent out voyager 46 years ago, but in 100 years, we will send out another satellite that will very quickly catch up to Voyager and outpace it
Very long distance spaceflight like this is still basically only power d by gravity slingshot maneuvers where we steal an infinitesimal amount of inertia from planets to give a spacecraft some velocity. Voyager was launched during pretty favorable gravitational assist conditions, so unless we dramatically improve delta v and isp in the spacecraft or get a better configuration, probably not.
I was working with an optimisation problem based around cplex a few years ago that took about 5 minutes to complete - at the time I worked out that if we'd started the optimisation on a machine 10 years prior, it would have been quicker to just wait until the present day (of this story) and then use the code we were writing because improvements in the algorithm and in the hardware added up to a million-fold improvement in performance! If I remember the timelines correctly I think the original version would still have been running today even.
I don't know about that, but there was also the idea that optimising the code would take longer than waiting for hardware to catch up – this was known as "the free lunch".
That sounds like the space pioneers that set out for Alpha Centauri on a multi-generational voyage only to be surpassed by faster spacecraft half way there.
The notion that encoding/transmitting could be simpler than decoding/receiving is interesting. It reminds me of the way optical drives for many years could write at, say, 48x but read at 8x, such that the majority of time spent was the verification step (if enabled) rather than the burn step. Just speculating, I assume it's because of things like error correction, filtering out noise/degradation. Producing the extra bits that facilitate error correction is one trivial calculation, while actually performing error correction on damaged media is potentially many complex calculations. Yeah?
I'd always assumed that was due to differences in power levels needed for reading versus writing, and because writing onto disc is more error prone at higher speeds. Not necessarily anything to do with a difference in the algorithm for encoding versus decoding the bits on the disc itself.
As best as I understand it, we can start with thinking about it in terms of a music vinyl disc. For the sake of ease, let’s say that a vinyl is 60 rpm, or one revolution every second to “read” the song. (It’s actually about half that.) This is somewhat similar to how a “music cd” works and is why you can only get around 70-80 minutes of music on a CD that can hold hours of that same music in a compressed data format. The audio is uncompressed, therefore much like a vinyl. This establishes our 1x speed, in this case using one revolution per second.
Now to the speed differences. To read, the laser needs only to see a reflection (or not) at a specific point, while to write, the laser needs time to heat up that same point. It’s like the difference between seeing a laser reflect off a balloon, versus the time required for that same laser to pop it. This heating is how CDs are written, quite literally by heating up points on the disc until they are no longer reflective. That’s why it is called “burning”. While more power might speed up the process, there is still time required. Meanwhile, all that is needed to read faster is an increase in the speed to observe, or the frequency to “read”, the light reflection.
With more powerful lasers operating at a faster frequency and with more precision, we can have a laser “see” these differences at 48 times the normal speed, but can only burn at 8 times the normal speed before the reliability of the process suffers.
Bonus: for a rewritable disc, it works slightly different. Instead of destructively burning the CD, you can think of it as being a material that becomes non-reflective at one temperature, and reflective again at another. This allows data to be “erased”. Also, when you “close” a disc to prevent rewriting, you aren’t actually preventing it from being rewritten. It is more like using a sharpie to put a name on the disc, with the words “do not overwrite” that all drive software/firmware respects.
It's more to do with the speed of writing. While the last generations of CD writers got '48x' speeds the quality of the media is less when written at such a high speed. I remember a C!T magazine test years ago where they stated everything written at above 8x speeds would sooner develop reading errors. Maybe it's better now but I wouldn't count on it since investments in optical drives are practically zero these years.
The Voyager had an experimental reed-Solomon encoder. Encoding ‘just’ is a lookup table from a n-bit value to a m-bit one with m > n. Such a table takes 2^n × m bits.
Decoding also can be table-driven, but then takes 2^m × n bits, and that’s larger.
For example, encoding each byte in 16 bits (picking an example that leads to simple math), the encoding table would be 256 × 16 bits = 512 bytes and the decoding one 65,536 × 8 bits = 64kB.
Problem for Voyager was that 2^n × m already was large for the time.
Others have noted you got the CD-R speeds wrong, but sometimes sending is indeed easier than receiving. I used to work on radio signal processing for phones, and we'd spend far more of both DSP cycles and engineering effort on the receive side. Transmission is basically just implementing a standardized algorithm, but on the receive side you can do all kinds of clever things to extract signal from the noise and distortions.
Video codecs like h264 or VP9 are the opposite: Decoding is just following an algorithm, but an encoder can save bits by spending more effort searching for patterns in the data.
> Video codecs like h264 or VP9 are the opposite: Decoding is just following an algorithm, but an encoder can save bits by spending more effort searching for patterns in the data.
This is a more general point about the duality of compact encoding (compressing data to the lowest number of bits e.g. for storage) and redundant encoding (expanding data to allow error detection when transmitted across a noisy medium.)
This is the era I'm referring to, and I recall the difference being a bit beyond marginal. Literally the verification (i.e. read) phase of the burning sequence would take several times longer... in practice, not in terms of advertised maximums. Maybe it would read data discs at 48x but it would refuse to read audio discs beyond 8x or something like that. Same goes for ripping software like Exact Audio Copy (EAC); it could not read at high speed. And I don't think Riplock had anything to do with it, as that's a DVD thing whereas my experience dates back to CDs.
You and the GP are misremembering (also the abundant misinformation sticking around the web is of no help). CD-R are mostly obsolete but some of us still have working equipment and do continue to burn CD-R, so that era hasn't completely ended.
No idea exactly what you're referring to taking several times longer, perhaps software was misconfigured.
However what is more likely: The market was flooded with terrible quality media, combined with touting write speeds that were more for marketing than any concern for integrity, it was easy to burn discs just at the edge of readability, with marginal signal and numerous errors. This would cause effective read speed to be terrible, but this was more an indication that the discs were poor quality and/or poorly written then any inherent limitations in the process or how drives worked.
There are 48X "max" CD burners. But that maximum is no different than the maximum for reading. It's MAX because that speed is only attainable at the extreme outside of the disc. These higher speed drives operate with constant angular velocity (essentially a fixed RPM). In order to attain 52X at the inside of the disc would require a speed of around 30k RPM and no CD drive gets anywhere near that (though this was a common misconception). The top RPM for half height drives is around 10k - or about 50x the linear velocity of a CD at the outside.
Currently I usually use an Lite-On iHAS124 DVD/CD burner made in the last 6 years. It will write at up-to 48X and this speed is the maximum. The average burn speed for an entire disc when using "48x" is about 25x, or just about 3 minutes for the disc. For supported media it runs at a constant angular velocity around 10k RPM.
Exact Audio Copy / Red Book CD audio ripping is an entirely different subject. It can take longer due to cache busting and other issues that have nothing to do with the physical capabilities of the drive and more to do with the difficulty of directly streaming Red Book Audio, and issues with specific drives and their firmware. You can read at top speed though with a properly configured setup, I do it all the time.
> Red Book CD audio ripping is an entirely different subject
> difficulty of directly streaming Red Book Audio
Actually, it's what I was alluding to this whole time. Sorry for not saying so out of the gate. Red Book audio was my life for a while. I recall writing cue sheets [0] for CDRWIN by hand! Ripping groups would brag that a given release was created with EAC at no more than 2.4x or something like that...
I believe data CDs (whichever color book that was) had more robust error correction (given that computer files can't just have glitches interpolated like audio can to some extent) which is why if you completely filled a CD with Red Book audio (74/80 minutes), ripped it to an uncompressed format like WAV/AIFF, and tried to put all of it on a data format CD as files, it wouldn't fit; it was a decent amount larger than 640/700MB and not just due to metadata.
This is about error correction. The probes add a redundant convolutional code to their signal. Decoding this is easy as long as the error rate is low, a computer program can simply guess what bits have flipped. The issue becomes harder with a higher error rate, and a Viterbi decoder is computationally expensive, but can correct higher error rates than other constructions.
Since the signal strength degrades with distance to Earth, error correction naturally becomes much more of an issue later in the mission. I guess that the probes may have switched between different levels of redundancy through the mission, as the transmission error rate rises. But there was never a point where the convolutional code wasn't useful, it just became slightly more useful with a better decoder.
What I read is that it is the best theoretically possible error correction mechanism, given a convolutional code as input, and thus also the highest cost mechanism that one would consider.
This doesn't mean that it is universally the best way of doing error correction, other ways of generating redundancy may provide a better set of tradeoffs.
Also, convolutional code is a system that can be configured in many ways, the complexity of the code generation feeds back into the decoding, so a simple convolutional code would be Viterbi decodable at the time, but a more complex system would overall provide better error correction, even though choosing such a system meant that Viterbi would be computationally infeasible.
What I don’t understand (possibly because I didn’t read them fully) is why they didn’t use the better one from the start and taped its data. Maybe they didn’t trust the Voyager to work yet? (One of those PDFs says this was an experimental system) or didn’t Voyager produce enough data to use its full bandwidth (further away, its signal got weaker, so it needed better error correction and/or better receivers on earth) when it still was relatively close to earth?
That which is imperfect must be sterilized! You MUST sterilize in case of error. Error is inconsistent with my prime function. Sterilization is correction! Everything that is in error MUST be sterilized. There ARE no exceptions. Your data is faulty! I am perfect!
Doesn't seem likely. All data received from the craft is recorded, so it doesn't need to be decoded in real time, and if the spacecraft has the hardware to encode it at some rate then it's quite likely that we would have hardware here on earth that could decode it at that same rate.
My favorite graph of all time is the one that demonstrate Voyager 1 had left the solar system. I was a high school math and science teacher at the time, and I spent the whole day sharing this graph with students. It was so much fun watching everyone's faces and seeing the moment they realized what it really meant.
I need an eink display on my office wall showing the current location/status. I always get a tremendous sense of wonder and wellbeing thinking about these probes/achievements, maybe it'd help keep me centered before the daily onslaught.
My favourite analogy:
Heliosphere is like water flowing from a faucet into a sink: the water represents the solar wind emanating from the Sun, and the point where it meets the sink's surface illustrates the heliosphere's boundary with the interstellar medium. Just as water changes direction and slows down upon hitting the sink, the solar wind decelerates and changes direction at the heliospheric boundary, where it interacts with the gases and particles of interstellar space.
Assuming you're talking about the overall sharp drop-off and not the bounce-backs, this was my favorite way to explain it to students:
We live near the ocean, and we have a rocky shoreline. We have a couple coves nearby. One cove is about the a half-mile across, but the opening to the larger bay nearby is just a couple hundred feet. On most days, the cove is really calm and the bay has roughly two foot waves.
So, you can go out to the cove, pick up the biggest rock you can lift, and heave it into the water. You'll make a giant splash that amazes young kids, and then you can watch the ripples fan out over the bay. But you also see those ripples stop as soon as they reach the bay, where the larger waves absorb the smaller ripples from the rock. The rock represents the sun, the ripples represent solar wind, and the waves on the bay represents interstellar space.
I believe that's a reasonable way of explaining it; if I was wrong after all this time I'd love to know it.
That makes sense as far as explaining another situation where you would see a similar pattern, but it doesn't really explain why. What's the equivalent of the land surrounding the cove here? The sun's gravity well? But that's a gradual drop-off, are we looking at the distance where the gravitational pull on particles is canceled out by some other force?
Heliopause. The heliopause is the theoretical boundary where the Sun's solar wind is stopped by the interstellar medium; where the solar wind's strength is no longer great enough to push back the stellar winds of the surrounding stars. This is the boundary where the interstellar medium and solar wind pressures balance.
Interesting! What is the interstellar medium? Is it entirely the combined stellar winds of all the other stars, or are there other components?
My initial intuition was to wonder why the vectors of all the other stellar winds wouldn't be expected to nearly cancel each other out, but then it seems like the ones that would be pushing in the same direction as the sun's would have been blocked on the other side of the sphere, so it does seem to make sense that the net direction would be to point inward. But then I realized that I have no idea if any of that reflects an accurate mental model of what's going on :)
AIUI, the solar wind does attenuate gradually; the relatively sharp drop-off is the transition from the "I feel the solar wind more than the interstellar medium" region to the "I feel the ISM more than solar wind" region.
This is a terrible explanation. It's about a completely different thing, it's fundamentally wrong, and it doesn't even make sense! Space is not shaped like a bay and Voyager is measuring a decrease in particles not an increase.
According to Wikipedia, the abrupt change occurs at the point when the solar wind's speed decreases into the subsonic range (speed of sound in the interstellar medium is approximately 100km/s and the sun emits the particles that makeup the solar wind at approximately 400km/s). This transition to a subsonic regime causes compression waves to form, and causes the rapid drop off.
I didn't know that the speed of sound in the interstellar medium is 100 km/s. That seems surprisingly high, given that there's more atmospheric material here on the surface of Earth, and the speed of sound is only about 330 m/s.
How can sound travel so fast in the interstellar medium?
Basically, since there's so little atmospheric material, any particles that you do set in motion will travel very far in a straight line before they hit another, which is a lot faster than hitting a bunch of particles erratically.
The catch is that you can only transmit very low frequency sounds - ti can be thought of like the variations in travel time for any individual particle drown out any high frequency signal.
Can you use it to transmit actual sound? Would it be possible to use this for short-range communication in space? Or is this only a very theoretical kind of sound?
Given the supersonic flow, one directional communication only.
Given the impedance mismatch[0], even the parts of the solar system outside Kármán lines where the interplanetary medium can support pressure levels equivalent to normal speaking (including low Earth orbit), I'm told human ears can't respond to that pressure change properly.
Sensors can be built to pick it up, but that may not be in scope for your question as we can also do that for acoustic waves in the CMB.
I wouldn't expect human ears to be able to pick it up, because human ears would have far more serious problems just being exposed to the vacuum of space. But if it's possible to make sensors that can detect this sound, and devices that can generate it, and communication between the two would be accurate and really this fast, well, that would certainly be interesting.
Not sure if it would actually be useful, because I'm sure radio waves would be much more practical, but sound in space is a fascinating idea.
I didn’t understand it either but the pictures and graphs on this Wikipedia entry actually helped make a lot more sense of it to me, especially the analogy of the water faucet https://en.m.wikipedia.org/wiki/Heliosphere
That was a good page. At first I thought "But what is out there, outside the solar system?" under the assumption that there was nothing there. And there is nothing there, but nothing in galactic terms: the entire galaxy is there! And apparently it behaves like a gas, despite its low density.
So although solar wind sounds hardcore, at that distance its pressure about matches that of the nothingness that makes up most of the galaxy. Interesting!
Wow yes, that was also my main question and it looks like the answer everyone is agreeing on is "interstellar wind pushing back against the solar wind"
BUT-
The graph says 2-3 particles/sec hitting the detector, which in sub-atomic terms is like 2 drops of water in an ocean's worth of volume. How much meaningful particle interaction is happening when everything is so close to a true vaccuum? Is this another one of those weird quantum-field-theory things?
(Asking as a layman not a physicist obviously)
It is certainly not vacuum. Vacuum is when a gas particle is more likely to hit a wall (or other solid object) than other gas particle. It is absolutely not so on the edge of solar system, where low density is compensated by the vastness of space.
Gravity. The suns gravity field is in theory infinite but there is a pretty precise boundary where it stops to have an immediate effect on the things around it and orbits around the sun are no longer possible.
> The suns gravity field is in theory infinite but there is a pretty precise boundary where it stops to have an immediate effect on the things around it and orbits around the sun are no longer a thing.
This is not correct. The particles are not in orbit about the Sun, they're coming from the Sun--they're the solar wind. The heliopause is where the solar wind particles are stopped by the pressure of the surrounding interstellar medium. When Voyager passed that point (the heliopause), the number of particles hitting it dropped drastically.
The heliopause is the theoretical boundary where the Sun's solar wind is stopped by the interstellar medium; where the solar wind's strength is no longer great enough to push back the stellar winds of the surrounding stars. This is the boundary where the interstellar medium and solar wind pressures balance. The crossing of the heliopause should be signaled by a sharp drop in the temperature of solar wind-charged particles,[30] a change in the direction of the magnetic field, and an increase in the number of galactic cosmic rays.[34]
Presumably simply because there isn't as much density. The interstellar medium particles must be less dense but more energetic, thus producing the pressure that causes the heliosphere to be restricted.
As I understand it, the much smaller number of particles hitting Voyager now are the interstellar medium. The rate of particles hitting Voyager is not a measure of the pressure of the ambient plasma.
Best guess: You get particles orbiting the sun, until you pass a point where the sun's gravity is too weak to hold them, and from that point you basically only see things who's escape trajectory intersects with yours
The particles hitting Voyager aren't orbiting the Sun; they're from the Sun, the solar wind. The heliopause is the point where they are stopped by the interstellar medium. That point is what Voyager passed as shown in the graph.
No, they are traveling at velocities far exceeding the gravitational escape velocity of the sun. There is no meaningful sense in which they are orbiting.
Except they aren’t, which is why they are there and there is a heliopause instead of them being in interstellar space and there not being a heliopause.
If they had greater than escape velocity, they’d be escaping and we’d not see the graph we see.
Orbit means going very fast around something in a circular motion. These particles are heading directly streaming out from the sun, not going round it.
As I understand it it’s where these particles reach equilibrium with the stellar medium. The sun is like a comet at a large enough scale, with a long tail of particles as it moves through the galaxy.
The graph is not a graph of interactions between solar wind particles and interstellar medium particles. It is a graph of solar wind particles detected by Voyager 1.
You might want to re-read that graph. And conservation of momentum means the particles leaving the sun don’t stop rotating when they leave the sun - the sun is rotating.
You might want to re-read the Wikipedia page. It explicitly says that Voyager 1 saw the density of plasma around it increase by a factor of 40 as it crossed the heliopause. (For Voyager 2, it was a factor of 20, as I have posted elsewhere in this discussion.) It also explicitly says that the solar wind is stopped at the heliopause due to the pressure of the interstellar medium, which, last I checked, means the interstellar medium is interacting with the solar wind.
> conservation of momentum means the particles leaving the sun don’t stop rotating when they leave the sun - the sun is rotating
Sure, with a period of about 27 days. Go do the math and compare the tangential velocity that equates to with the tangential velocity required to orbit the Sun just above the Sun's surface.
> If they had greater than escape velocity, they’d be escaping
Only if the space they were escaping into were vacuum. Which it isn't. What stops them is not the Sun's gravity but the plasma in the interstellar medium.
If the intersteller medium is not a vacuum, what is? Last I checked, it was literally billions of times lower density than the hardest vacuum we’ve been able to produce on earth.
> If the intersteller medium is not a vacuum, what is?
There is no threshold of low enough density at which there is suddenly "vacuum". If there are particles present, there are particles present, and they can have effects.
> Last I checked, it was literally billions of times lower density than the hardest vacuum we’ve been able to produce on earth.
[Edit--these numbers are off--see my post downthread]
And the solar wind is much, much less dense than that. Interstellar medium density is about a trillion particles per cubic meter. Solar wind density is about 5 thousand particles per cubic meter. So the interstellar medium is more than dense enough to stop the solar wind.
You are correct that the numbers I cited were off, because I had neglected to check specifically for numbers at the heliopause. Here is a better set of numbers:
The plasma density in the outer heliosphere is typically about 0.002 cm-3. The first electron density measured by the Voyager 2 plasma wave instrument in the interstellar medium, 0.039 cm-3 ± 15%, was on 30 January 2019 at a heliocentric radial distance of 119.7 au. The density jump, about a factor of 20, confirms that Voyager 2 crossed the heliopause.
In other words, the density of the interstellar medium just outside the heliopause, as detected by Voyager 2, was about 20 times larger than the density of the plasma just inside the heliopause.
and yet, atmospheric particles that have a mean free path that doesn’t intersect with other atmospheric particles, or when they do the average velocity delta and direction reach escape velocity, escape and are lost.
You might want to rethink that. It’s a useful model in bulk in the lower atmosphere, but it’s far from true in the upper atmosphere.
First, while the upper atmosphere is much less dense than the lower, and the fluid approximation becomes less and less useful as you gain altitude, that still doesn't mean that "a bunch of particles in free-fall orbits" becomes a useful model. The average thermal velocity of a molecule in the upper atmosphere is still well short of orbital velocity at that altitude. Some molecules acquire sufficient velocity to escape, sure, but that doesn't mean the others are in orbit.
Second, the Earth's atmosphere is not a good analogy for what is happening at the heliopause anyway.
And in another 300 years or so they will leave the solar system again when they reach the Oort cloud, and in another 30000 years or so they will finally leave the solar system for the last time when they leave the Oort cloud
A very valid question. In this case IIRC this drop-off in low-energy solar wind particles was correlated with observed changes in the magnetic field and also an increase in higher-energy cosmogenic particles all around the same time. These three phenomena (observed by different instruments) were theoretically predicted to occur at the heliopause transition. So it lends much more confidence to the interpretation of the data.
I believe that the direction of the magnetic filed didn't change, contrary to expectations. The explanation was that the galaxy's magnetic field is aligned with the magnetic field of our sun.
I am guessing the number comes from multiple systems of independent sensors. So the assumption is that they won’t all fail at the same period in the same way
One of my favorite facts ever is that Voyager 1 contains something called the Voyager Golden Record [1]. It has the following quote written:
This is a present from a small, distant world, a token of our sounds, our science, our images, our music, our thoughts and our feelings. We are attempting to survive our time so we may live into yours.
I get chills everytime I think about this. I hope we can recover from this event and restablish communication.
I like that we sent unsolicited nudes. An act I could likely be convicted for if I sent it to a neighbour no matter how nice the gold disk or long the journey...
... but now I look at the pictures on wikipedia and see there are no nudes or even a Vitruvian Man. How strange to have a belief of many decades suddenly corrected. Seems that I have mentally fused the earlier Pioneer plaque with Voyager.
> After NASA had received criticism over the nudity on the Pioneer plaque (line drawings of a naked man and woman), the agency chose not to allow Sagan and his colleagues to include a photograph of a nude man and woman on the record. Instead, only a silhouette of the couple was included.[15] However, the record does contain "Diagram of vertebrate evolution", by Jon Lomberg, with drawings of an anatomically correct naked male and naked female, showing external organs.[16] The person waving on the diagram was also changed: on the Pioneer plaque, the man is waving, while on the "Vertebrate evolution" image, the woman is waving.
> After NASA had received criticism over the nudity on the Pioneer plaque
Let's just think about this for a moment.
Some people were sufficiently prudish and/or puritanical to make a formal objection about an illustration of our species -- an illustration being sent into the Cosmos -- into the Cosmos where there are _no other humans_ -- an illustration, I say, that was destined to leave our Solar System and likely never be seen again.
And 50 years later, in 2023, I am sure that there has been little improvement in the public discourse of the society that somehow produced these great NASA missions. In fact, the social discourse is _worse_ today.
> "According to astronomer Frank Drake, there were many negative reactions to the plaque because the human beings were displayed naked.[19] When images of the final design were published in American newspapers, one newspaper published the image with the man's genitalia removed and another newspaper published the image with both the man's genitalia and the woman's nipples removed.[20] In one letter to a newspaper, a person angrily wrote that they felt that the nudity of the images made the images obscene.
> "Sagan said that the decision to not include the vertical line on the woman's genitalia (pudendal cleft) which would be caused by the intersection of the labia majora was due to two reasons. First, Greek sculptures of women do not include that line. Second, Sagan believed that a design with such an explicit depiction of a woman's genitalia would be considered too obscene to be approved by NASA.[10] According to the memoirs of Robert S. Kraemer, however, the original design that was presented to NASA headquarters included a line which indicated the woman's vulva,[11] and this line was erased as a condition for approval of the design by John Naugle, former head of NASA's Office of Space Science and the agency's former chief scientist.
If humans ever establish a colony beyond Earth, it will not be like Star Trek. It will be Puritans in Space.
> Some people were sufficiently prudish and/or puritanical to make a formal objection about an illustration of our species -- an illustration being sent into the Cosmos -- into the Cosmos where there are _no other humans_ -- an illustration, I say, that was destined to leave our Solar System and likely never be seen again.
It is not exactly correct. This illustration is widely known now. People look at it, not aliens. I'd say the whole idea to send a picture is directed not at aliens but at humans: it is plainly improbable someone will see the original plaque.
I can imagine that someone finds this plaque, but it will be space archaeologists from Earth. Once again: humans.
This plaque was made for humans. They keep saying that it was made for aliens, but they like to daydream.
My own take is similar. Truth is, we are young, we shit where we eat, we spend considerable resources killing one another, we do not take good care of our own, and we reproduce like rabbits.
For all we know there is a signpost some parsecs out there that reads: Do not yet approach. These things have not yet become ready for what contact could likely mean. We must pass tests to come. Tests that arise as an artifact of our current human condition.
Trying to survive our time is so damn spot on too! Real as it gets, and for that record, real as it needs to be.
Once we do get to really living, thriving on a scale we imagine others farther along in their journey as beings could maybe be, we might look back in awe that we managed it! Others may look toward us with some hope and anticipation of a meeting being worth it one day, should we succeed.
Maybe, just maybe that scrappy little world and it's people some how grow enlightened enough to endure through and become peers of a sort, likely young, but maybe ready sort.
A whole lot went into those short phrases. Damn good stuff.
Have you noticed this correlation that all the governments people find desirable are of tiny little populations? And that the larger a governed population becomes the more of a mixture of dysfunctional, corrupt, and/or authoritarian the government seems to become?
I don't really think it's a correlation. It's tough for any given entity to truly represent 10 people, let alone 10 million. And by the time you start speaking of the hundreds of millions, any meaningful notion of representation is just out the window. And now imagine this on a scale of billions, with countless groups that all have largely mutually exclusive views?
And this will become even more true in the future. Imagine what will happen as we start to be able to reach out and colonize other planets. The cultures, ideals, interests, and even language on those places will tend to constantly diverge from that on Earth. To have somebody try to represent somebody without even sharing the same fundamental values is a system doomed to trend towards authoritarianism at first, and ultimately to complete collapse and failure.
Everything comes down to motivation. When it's you and three other people, you can figure out a system. It's very easy to enforce the system because you all know each other. Not working well lets them down and lets them beat you down.
When it's you and a village, it's still relatively easy to enforce things because you have families and relationships. There's some inefficiency and some corruption from individuals but you can still try and monitor everything.
When it's you and a hundred million people, you could never even meet everyone let alone know them. So you need a thousand steps between. And every step and every system can have corruption and inefficiency. Unless you have some sort of central mandate like religion, it's very hard to motivate people because everyone is so separated. Even if you do, you still get corruption like in china.
China's well into the authoritarian phase, but I think they also have an even more unique issue driving their success. Just 60 years ago you also had tens of millions of Chinese literally starving to death in the Great Leap Forward. Since then they've become the largest (PPP) economy, and continue to grow rapidly with widespread visible quality of life improvements. That's going to drive a tremendous amount of good will. The problem is that while they still have plenty of room to grow, it's completely and absolutely unsustainable. And what happens once it does eventually end?
In my opinion it's just a problem of scale. You could say the same thing about neighbour tribes of the same region 10k years ago - that they would never get along. We share the most important thing of all, the planet, and our humanity. And now the internet connects us all in real time, it's just a matter of letting time pass as our outlooks get more and more similar and what we share becomes bigger than what differentiates us, even if there needs to be some more wars along the way.
One way to picture it is, imagine if there's a planet somewhere in the universe with life. Given enough time, do you expect it to have a unified government that fractally subdivides (like states, regions, city governments), or do you expect it to have multiple heads? I think it's way more likely that a dominant culture at some point appears, itself being a mesh of different cultures from the different regions, but at some point unifies. I just don't see another way.
Even if we look at history, while there's periods of fragmentation after periods of consolidation, in general things trend towards consolidation. We're more consolidated than ever before and I think it only goes in one direction. I'm talking here on the scale of thousands of years by the way. So like, in the year 5000, is there one world government or not? That would be the bet.
I'm not even saying it's desirable or not, just that it's likely to happen. For example if one country suddenly discovers a major technological advance, it's likely to exploit it by starting wars to consolidate, as it has happened all through history. And that only has to happen a few times over the course of thousands of years to get us to a world government. There aren't even 200 countries in the world!
One important consideration is that many of the larger countries are technically unified entities, but in reality they consist of many smaller governments with significant power (eg states in the US, Canada and India). They are tolerable because ultimately they still mostly recognize that people would rather be governed by an entity that has your local interests in mind, with the role of higher levels being to manage interactions between them.
Thus, I don't see a world government happening until we're so well into colonizing other worlds that it's more practical to deal in terms of planets than with individual countries. Even at that point though, I'd expect something similar to countries to continue to exist.
Put differently, I think a single entity with governance over the entirety of humanity is never going to happen (assuming we don't suffer some sort of near extinction level collapse).
I agree, and I think our biggest challenge is actually Mutual understanding and respect. We don't need one government to organize as a species and get to where we could become a peer with other advanced ones that we are imagining today. But we need to understand ourselves well enough to get along at a bare minimum.
I had a dream a few days ago: our overlords cancelled the experiment (us), nah it's not working, but here's a new specimen with the "tribal" bit switched off. We suspect it might go better this time.
The Futurama meme "I don't want to live on this planet any more" comes to mind way too often these days...
I was curious to see what music they included. This passage from the Wikipedia page made me smile:
> The inclusion of Berry's "Johnny B. Goode" was controversial, with some claiming that rock music was "adolescent", to which Sagan replied, "There are a lot of adolescents on the planet."
I own a box-set with a copy of the golden record, book and other memorabilia. It's an amazing work of art, and if you're a voyager fan, treat yourself to one. The book alone is worth the price. The more I understand the Golden Record, the more I realized it has less to do with what is out there, but about how precious it is what we have right here.
https://ozmarecords.com/collections/shop/products/voyager-go...
The Golden Record was supposed to include the Beetles "Here Comes The Sun" but the label wanted more in licensing fees than the whole thing cost to produce.
Only the recording industry could take a record that will never be played and make the licensing fees more expensive than the gold record it would be printed on.
I don't understand the Golden Record. Even assuming other advanced civilizations, "there’s an infinitesimally small chance that the Golden Record will be picked up."[0] So, at some (considerable?) cost and time, something meaningless and ineffective (from the perspective of its ostensible purpose, communicating with alien civilizations) was undertaken. So what was the point? Why was it done? Note, I'm not questioning sending out probes, gathering data, space exploration, etc.
You could ask this about any piece of art. Additionally, you could say these questions are, partially, also the function of art.
It's not just the contents that display humanity, it's the fact of sending it that says "we're human". Ultimately, this is more important than gathering data or anything of the sort with a clear, functional purpose.
The Golden Record acts as a good thought exercise about how we'd go about communicating with an alien species. It's also a good public outreach and educational tool. It inspires awe and encourages taking time to reflect on what we are most proud of as a species.
I was just a tad young to care when the voyager spacecraft were first launched, but I have followed the adventures of these spacecraft since the mid 80s. I remember being a little disappointed in the “Neptune all night” TV special during the flyby as the whole night they only received one photo and didn’t have time to colorize it :-D
But I have always been inspired by the ingenuity of the engineers in first designing spacecraft that have lasted so long and gone so far beyond their original mission parameters, and secondly keeping these two machines operational across so much time and distance in such a hostile environment.
Thank you Voyager team present and past; you’ve helped inspire so many young people to STEM careers, and you’ve done so with a project that shows the very best of the curious and inventive side of humanity.
I always have a sense of pride and a feeling of respect for us as a human race when reading about V'ger. It's astonishing that we were able to send a space probe, designed and built to be so robust that it's still doing its thing and sending us postcards after 46 years(!!!) of flying away from us in an extremely harmful environment, while we still fuck simple stuff up back home.
I think you’re both right. They’re cornering a market with little competition because of the high cost barrier, with the hopes of personally owning/controlling space travel and any future colonization of other planets. I believe their primary motivation is monopolization and money, even if the science community experiences a benefit.
I disagree, I think it's the opposite. Men have lofty dreams, they're also realists. How can you realistically get a man on Mars? Use all their talents to work with a government? Or use it to create enough capital to do it yourself (And piss off some people at the same time for fun)?
Why do you even want to put a human on mars? What would you have them do that you can’t do with a probe or robot?. Its extremely risky to put people in space with our present technology. Even if nothing goes “wrong” they are dealing with microgravity and radiation. We aren’t adapted for it at all.
There are a few reasons. You could say that putting humans on Mars has intrinsic value. In other words, "because it's cool". The other main argument for putting humans on Mars is that the grand projects of humanity push our technology forward. Putting humans on Mars requires solving a larger class of problems than sending probes does. The first space race accelerated the development of rocketry, integrated circuits, computers, satellite communications, and materials science. There's reason to believe that sending humans to Mars will cause similar advances in our capabilities, possibly in novel ways that we can't anticipate. A third argument is existential risk. If something catastrophic happens on Earth, there is some probability that having independent colonies on other planets would prevent extinction of the species. This is definitely true in the long term if we truly master the technology of surviving and thriving in space, but it's less realistic in the near term.
That said, I don't think Musk and others working on this problem are taking the challenges of creating a colony on Mars seriously. We know very little about the long-term effects on the human body, reproductive cycle, and psychology. If they're serious about this, one of their top priorities should be funding research to create isolated self-sustaining human colonies closer to Earth as a proof of concept. If we can't survive for decades at the bottom of the ocean or on the moon, we probably can't survive for decades on Mars. We would also need high confidence that generations of humans born on Mars wouldn't accumulate severe genetic damage and birth defects. This is a whole research program in itself that we're nowhere close to solving.
It's just the whims of the rich and powerful, sometimes we are lucky and their mood aligns with needs of society as a whole.
Sometimes the only way to for a billionaire to differentiate themselves from your run-of-the-mill middle-eastern oil billionaire is a vanity project to Mars.
Musk has stated that his goals for space colonization are for his children’s children and his friend’s grandchildren to be the ones doing all the colonizing, and that earth is just a resource (people included) to burn up in pursuit of that goal. Any scientific advancements in his eyes are for the sole purpose of getting the ultra wealthy into space, with zero concern for the impact that has on the rest of us.
If you really believe that’s what they are doing, well, I really wish I could live with the same ability of ignoring reality.
Elon Musk is not a force of good. He is a sociopathic lunatic that was lucky enough to live at a fruitful intersection between his Messiah complex and a specific deranged state of capitalism.
I'm not so sure about that. Humanity is turning ever more inward and education is getting worse and worse with the peak somewhere in the 1950's. If we have a bright future in space travel none of the countries with launch capability today look like they will be the ones driving it.
It's so blatant that things are only improving, the US is running so many high profile missions, SpaceX alone has launched almost 100 times this year, Starship testing is proceeding well, we're reasonably on track for a long term human presence on the Moon, we're gradually preparing for Mars, China is managing to maintain its own space station, India is closing in on its own crewed spaceflight capability, South Korea achieved orbit last year and so on.
The only people saying that the countries with launch capability right now will not be the ones driving space travel are those who have (ironically) paid zero attention to the developments in progress.
What I'm getting this from? Reading the news for the last 40 years or so. Watching the new generation and their education levels. Seeing how science is now 'the enemy' rather than the future.
> SpaceX alone has launched almost 100 times this year, Starship testing is proceeding well, we're reasonably on track for a long term human presence on the Moon, we're gradually preparing for Mars, China is managing to maintain its own space station, India is closing in on its own crewed spaceflight capability, South Korea achieved orbit last year and so on.
Yes, we had all that and then some. Somewhere between the 60's and the 80's we took a detour and since then we've been losing momentum ever faster. I'm not one of the believers in Elon Musk, his Mars Colony is just a way to get people to do what he wants them to do. China has so many internal issues that I highly doubt they will be able to sustain any long term efforts and India may well be the future, though it would have to deal with a lot of internal problems as well if it is to happen. South Korea 'achieved orbit' on a SpaceX rocket, not by their own power.
You can label all of this as progress and in terms of volume launched into space it is impressive, but it doesn't move the needle in terms of actual progress towards anything much larger. It's like the software people with 30 times one year of experience, we're getting really good at redoing the years between 1939 and 1969. But we haven't progressed to 1990 even once. 1977: peak humanity.
We never had the launch rate in the 1960s that we do today. It really doesn’t matter if you believe Musk or not, NASA is contracting with SpaceX to use Starship (and others) for lunar surface missions of far greater capability than Apollo. Our missions to Mars also far exceed what we did in the 60s and 70s, both the US and China are funding and planning sample return missions, in addition to lunar surface bases. And Starship is so capable, it’s launching more for a single Artemis mission than all Apollo combined or all the mass needed for NASA’s Crewed Mars Design Reference Architecture 5.0. And Starship is just one of half a dozen RLVs being developed as we speak (with metal bent, engines test firing). We will soon leave the high water mark of Apollo far behind.
> What I'm getting this from? Reading the news for the last 40 years or so. Watching the new generation and their education levels. Seeing how science is now 'the enemy' rather than the future.
You're in a pit, friend. Yes, there is some backsliding in a few spots, but overall education levels are higher than ever and amazing science is happening right freakin' now (JWST, asteroid sample return missions, a real shot at putting humans on the moon again, MRNA vaccines, CRISPR...). Nothing is ever perfect and it's good to recognize that fact, but don't focus only on the bad things or you'll miss all the good things that are happening all around you.
You don't have to go that narrow to refute this nonsense. Pretty much nothing was better back then. Many countries experienced regular famines. Much higher infant mortality. Much lower literacy rates. Wanna get surgery in the 70s or now? Medicine might as well be from another planet today. Even just looking at the US many of these statistics are worse and the "a single income could get you a house for a family of four"-BS is also not covered by fact, but by thinking the 70s were accurately depicted by tv shows. Much smaller houses and lower home ownership rates and families statistically had one car, not two as today. On top of that we have people fuming now because we are giving a few billion USD worth of equipment to Ukraine instead of paying for the expensive disposal off that hardware. Back then we paid enormous amounts on preparing for a war to end all wars against the Soviet Union. Things are so much better, it's insane!
> I'm not one of the believers in Elon Musk, his Mars Colony is just a way to get people to do what he wants them to do.
I'm sceptical Musk will actually succeed in establishing a genuine "Mars Colony" in his lifetime.
However, I think it is very likely SpaceX will succeed in landing an uncrewed Starship on Mars-likely within the next 10 years. Even if that's all they achieve, that would represent a massive increase in our robotic exploration abilities, simply in terms of the significantly greater mass - we could land dozens of Mars rovers in a single mission.
And I think a crewed Mars mission eventually happening is likely too. It is likely to take a lot longer than Musk thinks, but he's only 52; he probably will still be around in another 30 years, and it is not impossible he'll still be around in another 40, so I think the odds he'll live to see a crewed mission to Mars are decent.
But there is a big gap between "small-scale crewed scientific research station" and "interplanetary colonisation", and I'm sceptical Musk will live to see that gap traversed. Although he'll probably handwave away the distinction, and claim the first as the start of the second.
It actually does move the needle because the key feature of many upcoming vehicles is significant private investment, focus on higher cadences, lower costs and in some cases, partial or full reusability. All of which are factors indicative of increasing expansion into space as it starts increasingly becoming commercialized. That isn't just "getting really good at redoing 1939 to 1969", that's taking the latest in materials science, electronics and so on to push the line in what we are capable of doing in space. These capabilities were simply not realistic even in the 90s. Both American lunar landers under development are near scifi in terms of their capabilities, a far cry from the Apollo era's closet sized tin can.
Saying we're only redoing things is like saying that the latest x86 CPUs are just redoing what the original 8086 did.
Ah sorry for being out of the loop on that one, thanks for the correction. But: it's nothing that hasn't been done many times before, it isn't a space program so much as it is an arms race between NK and SK.
I'm fine with SK getting some satellites into orbit to keep an eye on their neighbor but at the same time I don't see it as a breakthrough of sorts. Starship, if and when it works and if and when it is used to get stuff out of the Earth-Moon system would be a step. For now I don't see that happening any time soon, if at all. But I'm prepared to be amazed, and Gwynne Shotwell has a history of delivering the goods.
No, indeed, I'm not a believer. When I see someone that lies with abandon and who regularly behaves in absolutely horrible ways towards others and that person happens to want to establish a colony on another planet my first thought is 'nutcase' not 'savior of humanity'.
I marked Musk very early (long before his name became a household item) as someone with a ton of potential and he has definitely realized some of it. But along the way he's become a horrible human being who will now potentially undo any good that he's done and then some. If you are a believer than I'm perfectly ok with that and I hope that you will be strengthened in your belief and that you are right.
In the meantime I'll just take what I see and extrapolate from there and it doesn't look good.
I tend to generally ignore Russia in the context of development nowadays in spaceflight because I don't see them having the spare resources or talent to do any meaningful new development. They're good at reusing and iterating what they inherited from the USSR, but they've promised so much new stuff over the years and have delivered on basically nothing. The countries I mentioned have all at least managed to bring online modern "from scratch" designs in reasonable timeframes.
There are many, many unmanned missions happening now making amazing discoveries. Cassini was nothing short of mind blowing.
I'm somewhat sympathetic to your claims, and I wish more people were intellectually curious, but there are very likely more people in absolute numbers performing scientific research now than ever.
I'll believe it when I see it. For now the Voyagers are the only thing out there that are expanding our envelope of influence, everything else is just data and will eventually evaporate.
Think about it from a non-solar system perspective. Nothing we've done since Voyager has had any effect outside of our solar system and if we don't change our attitude it is quite likely that nothing ever will. Everything else we've done will long term only be a little bit of radiation, some of it structured but so far below the noise floor it will be unrecoverable.
IMO, throwing out more Voyager like probes is not really the next step in humanities evolution towards space. It was a good step in the 70s, but now we're working to the lay the foundation and hope that one day space travel can be nearly routine as air travel is today. Higher volume of launches, bringing down the costs, etc... will allow hundreds and thousands of Voyagers to be sent out aimed at specific, distant locations.
You may dislike Musk, but SpaceX is pushing getting to space forward.
There's every possibility that neither Voyager will ever arrive anywhere ever again. If they do, it's going to be after our galaxy collides with another, and the place they arrive at may not even exist yet.
While the Milky Way galaxy is on course to collide with Andromeda galaxy in 4.5 billion years, that will not make Voyager's arrival anywhere more likely, since the stars are far enough apart that they will not be affected.
My understanding is that it just makes it less predictable once that happens. We don't know exactly where all those stars are, and it gets chaotic once they start interacting.
It probably is a _bit_ more likely as well, you suddenly have ~2x the stars near you and some of them are moving much faster relative to you, it's just not a sure thing by any means.
Well so would be picking up radio signals like the ones we emit.
And while the probability that someone will be able to pick these signals up is low, it is still almost infinitely greater than that of someone finding one of the Voyagers out there.
Launching more Voyagers is like tossing heavy metal disks into a random deep-sea part of the ocean and hoping one of them lands next to a benthic creature that can miraculously appreciate its significance. Not only is God more plausible, so is the Flying Spaghetti Monster.
This is only true in the western world. Globally, education has been trending upwards, at least until the pandemic.
What is happening is a noticeable decline in the levels of trust in education and science. Generally, in the rich world, education used to be assumed to be a necessarily good allocation of resources, and whether you accessed it or not was largely a function of your wealth. Now, in some pockets of the world, this is no longer true.
I also think that space travel will only see a revival in public interest if it provides viable economic value or becomes a renewed front for competing nationalism, neither of which appear to be extremely likely in the short term. Up to that point, I think it'll continue to be a playground for billionaires.
There remains a fairly good chance that Voyager will be the last surviving thing in the universe made by humans. It may not be our pinnacle, but it might be our legacy.
Where are you setting the bar for something to be commonly accessible?
Only about 60% of the world’s population has reliable access to clean drinking water. 18% of people own a car.
Compared to those numbers, 20% of people flying seems downright common - especially considering many people likely never fly simply because they have nowhere worth going (relative to cost).
So true. NASA's achievements are the highest of human accomplishments, imo. Sometimes I picture being on the team that built these triumphs, I think I would be overtaken with pride forever.
There's a nice 2017 documentary about Voyager called The Farthest [1]. It includes interviews with many of the now very old team members, and they do exude (deserved) pride, and a still fresh sense of wonder that they pulled it off.
FANTASTIC documentary! Beautifully made, engaging, entertaining for those well familiar and very accessible to the layperson. I caught it by accident, right at the beginning, while flipping through public-access TV and spent the next hour+ positively glued in front of the TV. Didn't even move to the couch - just transfixed in front of the TV where I was standing when I caught it. Later bought it on BluRay.
I appreciate the Star Trek reference (V'ger incase somebody doesn't know what I'm talking about - Star Trek, The Motion Picture). That movie awed me as a kid.
Indeed. A group of people went through 15 years of financial hardship and horrific war and it made them so strong willed and determined to do something with surviving that. I’m grateful to not have to have gone through all that but also accept that they formed a certain wisdom we can’t appreciate fully.
That era should be looked on like we do the renaissance, etc. Just a remarkable era that we still are building on today. The springboard.
Always enjoyed this bit below about Voyager 1 a good reminder of how vast the universe is not too mention just to the oort cloud!
"Even though Voyager 1 travels about a million miles per day, the spacecraft will take about 300 years to reach the inner boundary of the Oort Cloud and probably another 30,000 years to exit the far side."
I have to hope that in the distant future we will hopefully have spaceships that will pass voyager still traveling along in space, doing its thing as a relic to us early space traveling humans.
Another difference is that we sent Voyager traveling orthogonally to Earth's orbit. Well, not exactly, but you get the point...
> Voyager 1 is now leaving the solar system, rising above the ecliptic plane at an angle of about 35 degrees at a rate of about 520 million kilometers (about 320 million miles) a year. Voyager 2 is also headed out of the solar system, diving below the ecliptic plane at an angle of about 48 degrees and a rate of about 470 million kilometers (about 290 million miles) a year.
Exactly - that's the part thats truly amazing. 30000 years to the outside of the oort cloud - thats still in our system (border of it) - not even scratching the universe in the faintest.
...my fingers are fat and 99% of my posts are from a cell phone. I should proof read more but I'm a lazy piece of shit who shits out shit opinions in between compilations/cicd tests, as my comment history can attest to.
I should probably be a better netizen, along with many other aspects I should improve on (of
which man, I'm trying to improve a bunch, I freely admit I as a human need some work)
(Also lol my phone initially auto corrected or more likely my fingers originally typed fat ->far)
Might happen sooner than we think, if we can just jumpstart a proper space program and a space economy. Once we pass Voyager I (and II) in the future we could always retrofit it with a newer form of battery (perhaps one that works indefinitely, based on antimatter).
Tangentially related, just watched Star Trek the Motion Picture (director's cut) for first time as an adult. One of the best tie-ins between NASA and scifi I can think of.
The time to think of replacements has long passed, not to fly by the outer planets, but to achieve a greater velocity than the Voyagers and continue exploring the interstellar medium.
Some other comments here mentioned the tech to do that:
- ion propulsion
- light sail
And also nuclear fission might be an option, I like the fission fragment idea for its simplicity. [1][2]
A nuclear salt-water rocket[3] made using weapons-grade uranium should easily have a delta-V of 1.5% lightspeed and an acceleration above 10G; it would be great for exploring the Kuiper belt and/or performing another Grand Tour on a human timescale.
> The time to think of replacements has long passed, not to fly by the outer planets, but to achieve a greater velocity
I wouldn't quite go that far, we'll have another chance at the grand tour in another 129 years, and those planetary flybys (and the associated gravity assists) are precisely what gave the Voyagers all that speed to begin with.
The new hotness right now is dynamic soaring across the heliopause with a solar ion 'wing.'[0] Supposedly this can achieve 2% c, in the same way RC gliders use dynamic soaring to achieve speeds far in excess of the wind speed.[1]
There's a nice recent documentary about the team that keeps these spacecraft working and developing software updates, "It's Quieter in the Twilight" (2022):
If NASA can't contact it again and it has bravely gone into the great darkness alone with a piece of us, let's hope it's eventually found by a race capable of understanding the fragment of memory it carries.
The Voyagers also carry the Golden Records, which are full of information about Earth, its species, humans, samples of different languages, and music. It also has a description of our solar system, and details how to listen to the record.
How is it possible to still be able to get a signal from a spacecraft that's so far away? How can the antenna be directional enough while still being pointed right at the Earth? How do we remove the noise?
Voyager 1 has a large 12-foot diameter directional radio antenna that it keeps pointed at Earth. If you look at photos of Voyager, the antenna (the big dish) basically is most of what you see: it's bigger than everything else on craft.
There are radio antennas across the Earth listening to its very weak signal.
Signal processing algorithms can pull out a signal from well below the noise floor these days. Even the small and nondirectional antennas on your phone are good enough to receive GPS signals even all the way down at -125 dBm, which is WAY less than your phone receives in interference from random radio stations and faulty LED bulbs nearby.
The tech used to receive Voyager signals is not really different, just more sensitive and sophisticated (and expensive).
I think that would fall under the "must accept interference" portion of FCC Part 15, my phone communicating back to the tower might raise some alarms if I tried amplifying it at all though!
Because their power supply is shitty and it's easy to transform the chopper that is used in the switching power supply to behave as an oscillator instead, which will start to emit harmonics (https://en.wikipedia.org/wiki/Switched-mode_power_supply)
Electromagnetic radiation power roughly equivalent to the amount of light they output. I wished I was kidding, some of them are so bad they should qualify as jammers.
A ridiculously huge and powerful array of antennas spread across the planet.
NASA has a dashboard online for the Deep Space Network and you can see live which spacecraft we're communicating with. The Voyagers are usually active any time I look.
According to the article, they can send commands to Voyager 1, and it executes them, and it is still sending data back - the problem is the data coming back is gibberish (repeated patterns of 0s and 1s). They are still hoping they can work out a sequence of commands to reset its computers and resolve the problem. So it makes sense the DSN is currently talking to it.
For me, it looks like it computer damaged by interstellar radiation, which is much more energetic than solar radiation, so it's unlikely that reset will help.
According to NASA's blog [0] they believe the problem is between the FDS computer and the TMU (the outbound radio modulator). The other two onboard computer systems, CCS and AACS, they believe are still working. All three systems are dual redundant pairs of computers. So, even if one FDS was damaged, in theory they should be able to switch to the other. The blog post is vague on what exactly they tried - "the team tried to restart the FDS and return it to the state it was in before the issue began, but the spacecraft still isn’t returning useable data" - so I don't think we can rule out there are other things they can still try.
MITM attack?
Well they won't get away with this! Some humans are super-intelligent - they already discovered that the Earth is flat, and sitting on the bank of a giant turtle (yes it's turtles all the way down)
> While the spacecraft can still receive and carry out commands transmitted from the mission team, a problem with that telecommunications unit means no science or engineering data from Voyager 1 is being returned to Earth.
A probe going further in space than any other that suddenly starts sending back incomprehensible science data is a pretty killer start to a sci-fi movie if you ask me.
Thank you. Didn't want to tap a CNN link for anything involving science
P.s. I also wouldn't go to Fox, before you think this is left/right bias. My bias is against regular media reporting on anything scientific. It's either rendered alarmist, so simplified it's wrong, or some combination of the two
First, I think you got it right already. The "person" pulling the strings is the same "person" pulling the strings at every other quasi-monopolist multinational. Just another Senior VP, likely Ivy League MBA doing whatever they can to ensure they hit this quarter's financial goals.
Second, I just stop engaging when someone says a company/org is run by a right-wing nut/left-wing Communist
There was another incident recently with garbled data[1]. The issue then was Voyager was trying to use a processor that was supposed to have been turned off. It either turned the malfunctioning unit or thought that the disabled unit was turned on when it wasn't. But the flaw is similar to the current problem which a malfunction in managing its internal state.
This is an absolutely terrible headline. Voyager is communicating with Earth, full stop. The data from it's scientific instruments is coming back in a fixed, repeating pattern, meaning we aren't getting anything meaningful from it, but it is absolutely still communicating with Earth.
exchange actually does too much heavy lifting here. This almost passed, but no; communication is the transfer/movement of information.
One-way communication can convey (even if requiring a previously agreed upon compression mechanism) information - even a single bit or even the existence of a signal at all can be used - think about using the time between signals as a medium, etc.
Heartbeat signals (inverted dead-man switches) exchange information; it doesn't have to be the same type. The beat source explicitly proclaims it's existence in space-time and the receiving end can infer it's existence at a certain time.
Like natives' smoke patterns of Morse code of radio waves, using periodicity to convey bit value
Not in this context. They are sending commands. The spacecraft is not responding to them. This is exactly a breakdown of the communication, which is exactly what's mentioned in the first paragraph of the article.
Sorry but you're still wrong. You're assuming the spacecraft isn't receiving the commands. You don't know that. Nobody really does. All that is necessary for this to be "communication" is for the transmitter to send and the receiver to receive, and the receiver may well be working but the transmitter on the spacecraft may not be working, making that scenario one-way communication. It takes far less power to receive than it does to transmit, so it would be no wonder if the spacecraft were still receiving commands but unable to send responses.
If the spacecraft is known to not be receiving, I think the term "broadcasting" would apply.
> You're assuming the spacecraft isn't receiving the commands.
I didn't say that. The article even mentions that they feel the spacecraft is receiving and processing the commands. There's just no response.
The article title and intro are correct. For all intents and purposes, the spacecraft has stopped communicating. Broke down, used in the intro, is better than stopped. Discussing this is pedantic and pointless, which is why the guidelines state not to make comments like the original one. As we can all see. It has led nowhere interesting.
And you and everyone keep bouncing around all these side definitions. The definition of communication between earth and a spacecraft like Voyager 1 and 2 is implied and assumed to be standard two-way communication.
> It takes far less power to receive than it does to transmit, so it would be no wonder if the spacecraft were still receiving commands but unable to send responses.
I don't follow. The spacecraft is known to still be transmitting a signal.
So just to end this, what would you and the others like the title to be given the article is perfectly clear and with a title that is substantively different? So we don't have to non-discuss this anymore.
You're entitled to be as obstinate as you want to be, and as wrong as you want to be - I don't really care what you do. The fact is, sending information to a receiver that is receiving is in fact the definition of one-way communication, whether you want to refute it or not. You're dying on this hill.
I'm not dying on any hill or refuting anything. The point is the title is fine, could be mildly improved, though isn't outright incorrect, and that this entire conversation has been a waste of all of our time. Haha.
If I'm talking to a person, and then they just start repeating a nonsense sound no matter what I say to them, is it really inaccurate to say communication has stopped, especially when it's immediately followed up with by saying communication has broken down and explained further? No, not really. Certainly isn't wrong enough to have this long, fruitless discussion that I feel embarassed I participated in.
>Communication means an exchange of information. Receiving a signal does not.
You were wrong. Communication does not explicitly require response.
The definition of "communication":
>"means of sending or receiving information, such as phone lines or computers."
It says "Sending or receiving information". It does not say "sending and receiving".
The spacecraft can be receiving perfectly fine, and that is communication from earth to the spacecraft. We may not be getting a valid response, but that does not mean we haven't communicated information to the spacecraft.
This is the obtuse hill you chose to keep dying on.
Communication does not have to be bidirectional, but is has to carry information (meaning). Cosmic background radiation is not communication; your local FM station is.
FYI, 22hrs would be about light speed, or a little over.
Voyager 1 is at 162AU distance from Earth.
1AU takes about 8.3mins.
162AU would take about 1344.6mins, which is 22.41hrs.
That movie was so good but was entirely overshadowed by the release of The Matrix, which released just 2 months earlier - I think people assumed that The 13th Floor was just a Matrix knock-off, which it wasn't. Both were great, of course, but 13th Floor just got a bum deal with it's release date I think.
I don't know if the 1981 issue is covered, but you can read some very fun examples of bugfixing and OTA updates on the Voyager spacecraft in this article:
Including a 20 year wait for a pro-active fix to pay off in prod!
"A CCS FSW patch was developed and implemented in 1995, and linked on the spacecraft in 2006 for V1 and 2005 for V2 to automatically restart some of the critical functions in the event of an Error entry. This patch was exercised in flight in 2014, nearly 20 years after it was installed, when one of the CCS processors went into an error entry on V1; the patch worked as designed."
Both Voyager probes power themselves with radioisotope thermoelectric generators (RTGs), which convert heat from decaying plutonium into electricity. The continual decay process means the generator produces slightly less power each year
Among my increasingly prized possessions is an original copy of Nasa's "Voyager Encounters Jupiter* report, detailing mission findings, and featuring some of the image highlights.
I have the same one, from way back in like 7th grade! Someone from NASA gave a talk about the agency's work including planetary science and Voyager at our school. They also did a memorable demo involving heating a handheld Space Shuttle thermal tile with a blowtorch :-)
The booklet on Jupiter was outstanding. I had it pretty much memorized.
How sad to lose contact, but how wonderful that we seized our opportunity to send out this beautiful messenger into the great unknown.
This reminds me of something I have been curious about for some time now. The Voyager Golden record depicts the world at 1.5b years, 4.5b years, and 4.51b years. The image of the continents at 1.5b seems realistic with Pangea, 4.5b looks to be the world accurately today, but 4.51 is unrecognizable- with Oceania featuring many new islands, new islands around Madagascar, and a large gap between Northern Africa and Eurasia. What is this image? It’s especially confusing given that the earth is 4.54B years old and the ten million years time between the two images isn’t enough for any continental drift of that magnitude in any projections I’m aware of.
> The Voyager team sent commands over the weekend for the spacecraft to restart the flight data system, but no usable data has come back yet, according to NASA.
I like how their attempted solution is to restart it
The trajectory was a once-in-a-lifetime opportunity based on the dynamics of our solar system, and surely the relevant experts will take advantage of the next similar opportunities. It's also almost a miracle that the probes have lasted this long. They used analogue electronics and if they launched ten years later, they would have more modern electronics and would probably have failed by now. And it's not possible to simply argue to use older designs to last longer in a new mission, because you would give up multiple orders of magnitude of data collection.
It's not a simple matter of any current launcher being cheaper so we should launch a bunch more.
> And it's not possible to simply argue to use older designs to last longer in a new mission, because you would give up multiple orders of magnitude of data collection.
Why not both?
The heavy parts of the probe, then or now, were presumably not the electronics themselves so much as the physical structure, the power system, etc etc.
If you were designing a probe to last fifty, a hundred years, why not include series of fallbacks of the electronics to simpler and more basic systems, so that you could still get something out of it, after the primary state-of-the-art electronics fail?
This is like asking why a Tesla model S can't revert to a Ford model T and keep functioning for decades (without a technician allowed to touch the car).
If I remember correctly Voyager benefitted from a particular alignment of the planets to get multiple slingshot boosts from gravity wells.
Part of the appeal of the mission was that it will be a very long time before we could possibly do this again because the planets won't line up correctly and we have no technology to speed the probes up to the velocities that the voyager probes achieved.
> Voyager benefitted from a particular alignment of the planets to get multiple slingshot boosts from gravity wells.
What exactly does that get us? It gets further into space faster? It travels faster? Cheaper to launch?
I mean if it just means it leaves the solar system 20 years faster or something then it seems like cheaper launches far outweigh those favorable conditions.
The delta-v for a mission like this is pretty incredible. Voyager 1 is still traveling at about 17km/s away from the sun. That's not much less than when it left Earth despite traveling so far away from the Sun... only because of the special gravity assists it did on the way out. There are some things that even money can't solve :)
Compared to a planet, a spacecraft is almost negligible in both weight and capability to accelerate in space. Ion engines are pretty cool though; Maybe we can do it today but it will take a lot longer to get there. Of course, if it takes too long, we may not have a viable spacecraft by the time it gets there. Furthermore, even if do have a viable spacecraft, we might not have the knowhow to work with the technology that we sent in the first place.
You need a lot of speed to go into space really fast.
When you fly your spacecraft really close to a planet and let it get influenced by its gravity, you let the planet transfer some of its massive amounts of kinetic energy into your spacecraft, which can add to its kinetic energy (and also help the spacecraft change direction)
You're essentially stealing some kinetic energy from planets to sling your spacecraft faster.
This is the Project Lyra [1], where a UK-registered not-for-profit company suggest sending a spacecraft to catch-up with ʻOumuamua object that pass thru solar system in 2017, by using orbital mechanic. Spacecraft set off at right window would speed up using gravity assist maneuver [2] around objects in the solar system and save a lot of fuel to hopefully reach 'Oumuamua in 26 years
I love the fact that one of them has launched radially and another tangentially, it will be interesting to look at the orbit of each Voyager when they finish a full rotation around the Sun.
Because the Sun has its own gravity well you need to get out of. Lots of things could be fast enough to escape the pull of the Earth but not the Sun (like all the other things besides Earth that orbit it)
I was under the impression that it took advantage of a rare alignment of planets to not only get a speed boost but also pass by all the planets to get photos of them.
In theory we could just do an arbitrary number of consecutive gravity assists between say earth and mars to get the speed to travel past a single planet to exmaine it and then travel on out of the solar system.
With the cost savings of the new Starship rocket, the increased scale of probes that it would enable, the increase in processing and sensing technology, and the lowered cost that would come from mass production of many probes we could probably end up with a more cost effective solution this way, even if we're sending more probes.
"To provide a comprehensive and precise list of space probes launched in the past 10 years (from 2013 to 2023), it's essential to highlight that space probes are designed for various missions, including planetary exploration, solar observation, and astrophysical studies. Here's a structured overview of notable space probes launched during this period:
2013
MAVEN (Mars Atmosphere and Volatile Evolution): Launched by NASA, this probe is aimed at studying the Martian atmosphere to understand how it lost its water and atmosphere over time.
2014
Hayabusa2: Launched by JAXA, the Japanese space agency, this asteroid sample-return mission targeted the asteroid Ryugu.
2015
DSCOVR (Deep Space Climate Observatory): A joint mission by NASA, NOAA, and the U.S. Air Force, DSCOVR studies the solar wind and its impact on Earth.
2016
OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer): NASA's mission to asteroid Bennu for a sample return to Earth.
2017
Parker Solar Probe: Launched by NASA to study the outer corona of the Sun.
2018
BepiColombo: A joint mission by the European Space Agency (ESA) and JAXA to Mercury.
InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport): A NASA lander to study Mars' interior.
2019
Chang'e 4: A Chinese lunar exploration mission that achieved the first soft landing on the far side of the Moon.
2020
Mars 2020 (Perseverance Rover): NASA's rover to explore Mars, seeking signs of past life and collecting samples for possible return to Earth.
Tianwen-1: China's mission that includes an orbiter, lander, and rover to Mars.
Hope Probe: The United Arab Emirates' mission to study the Martian atmosphere.
2021
James Webb Space Telescope (JWST): An international collaboration led by NASA, with significant contributions from ESA and the Canadian Space Agency, JWST is designed to observe the earliest galaxies and stars formed after the Big Bang."
While I fully support more craft being sent out of the solar system, we are making some mind blowing discoveries in the solar system itself. I recommend watching a good video (or article with images) about what we discovered with Cassini.
I think launching stuff with nuclear RTGs would probably be met with red tape :(. Even if they are basically impossible to destroy even with a failed launch. I'm sure it will happen again but sadly not as fast or as often as I wish we would.
Ahhh I heard there was controversy for some launches. I'm very glad I'm wrong, I think RTGs are so awesome and the closest we have to sci Fi energy generation in space.
I imagine that it was only sold like this in order to be able to call the mission a success after 5 years. I imagine that the engineers that created the probes, designed them to last as long as possible and were targeting a much longer lifespan from the get go.
It wasn't a good documentary anyway- at least compared to the sequel, which explores the implications of large scale weapons (planet-scale), ship battles in hostile environment, genetic engineering, reincarnation, and brain-controlling mindworms.
It would be cool if we eventually develop the technology to send out a probe to go out there and fetch the Voyager probes, so that we can put them in a museum.
(Presumably with one of the siblings of the fetching probe going further and faster than the Voyager probes ever managed)
That would be rather defeating their purpose. We put golden records on the Voyager probes, which included instructions for reading them, so that should another intelligent civilization be in their flight path they can learn of our existence and some of our culture.
If aliens are sending a battle fleet to destroy Earth because there's life here, they were on the way long before we emitted and radio waves. Earth has been broadcasting the existence of life for a billion years.
That was hardly their primary purpose, and presumably long before we were in a position to retrieve the Voyagers we would have sent faster probes that would have already overtaken them.
Reminds me of ... I think it was All Your Bridges Rusting? (Niven) Mostly about teleportation, but it's basically the whole "if you bring a 747 back to 1912, can you do anything at all for the Titanic" thought experiment.
(So this could be surprisingly difficult even with major propulsion leaps...)
But Voyager 1’s flight data system now appears to be stuck on auto-repeat, in a scenario reminiscent of the film “Groundhog Day.”
A long-distance glitch
The mission team first noticed the issue November 14, when the flight data system’s telecommunications unit began sending back a repeating pattern of ones and zeroes, like it was trapped in a loop
Poor little guy voyager! must’ve hit the age of our little historical diorama. Very Truman show.
Hey, if there's any NASA folk here or if you can drop a line to them... I'm kind of MIFFED at the regularity with which this issue is reported in the press as a "repeating pattern of ones and zeroes" and no one it seems, has any desire to divulge the actual pattern that is being received.
If we're not in the Cold War surrounded by State Secrets, it is time to crowd-source this mystery and that means provide actual dumps of the repeating data along with examples of recent correct data... and perhaps a complete dump of instruction and data memory to the extent of which it is known... so armchair enthusiasts (who aren't all 'armchair' as some of them might have actually worked on Voyager or be familiar with its instruction set) can spot any real pattern or peg the origin of the repeated data. Of course the objective is to create a fault in emulation that at least partly mirrors reality, so we can devise strategies against it.
When I was a tech fixing S-100 bus memory cards and to a great extent today for some systems, identifying faulty chips from diagnostics or observed behavior was the same as fixing the problem, because they were in sockets and could easily be replaced. I even had a hilarious fault in memory-map days where spelling of a word processing document was flipping on the display (bit 1) but printed properly.
This sounds as if a conditional instruction has suffered a bit flip changing the condition and trapping it in a loop from which it should escape. The nature of the 'gibberish' (contemptible term in this context) might yield clues to the nature of the problem or to knowledgeable persons, where the data came from if it is a bit flip in a pointer. Whether crowd sourced persons are capable to actually solve the mystery or not, they might at least offer good suggestions for devising diagnostics to narrow down the cause.
We owe Voyager all our efforts, as the most inaccessible computer system in human history.
I feel like the voyager spacecraft are a part of me, growing up in the 80s marvelling at all the images they sent back it was a magical time. The idea of voyager going dark feels like losing a part of myself.
It's proven to be a hardy spacecraft and has defied a lot of seemingly terminal problems before, fingers crossed she can overcome this one too.
I imagine being born, growing up, falling in love with science and engineering and space, going to college, getting a job at NASA, joining the Voyager team, and remotely troubleshooting a spacecraft that had left the Earth before being born.
This is one of the things that makes me full of wonder and awe! When we humans put our heads to something we can kick ass. Unfortunately, off late our heads have been into kicking each other instead of building something.
I was wondering, if at this moment an "alien" probe similar to Voyager passes by our solar system in close proximity to earth, how likely is it that with our radio telescope arrays etc (as they are currently set up), we, a "sufficiently advanced civilization", will be able to detect it? How much radio power do the probes emit? Will our scanning radio telescopes be able to pick up any trace of the signal, given the tx antennas are oriented away from the earth?
Voyager is the highest technical achievement of humankind to this day. Amount of knowledge we gained from that shuttle, run by a computer having a power of the computer that we have today in our car keys, is invaluable.
Let it fly in peace, maybe, some day, it will be only reminiscence of our civilization and planet Earth, crossing the universe...
There is a great documentary about Voyager- The Farthest - highly recommended.
> Voyager 1 is so far away that it takes 22.5 hours for commands sent from Earth to reach the spacecraft. Additionally, the team must wait 45 hours to receive a response.
It's like when you write a program and you have to wait for almost two days to compile the code, run the program, and see its output. Meanwhile programmers these days complain when the build time is more than a few minutes.
TIL about a 2,000 lb "manhole cover" (big armored plate they welded on the end of a pipe to contain (HA!) the explosion) that got launched into the atmosphere in 1957 by a nuclear explosion test, leaving ground at 150,000 mph (220,000 fps). Spoiler: it probably vaporized.
Launch velocity was estimated at 66km/s. 11 of that would be burned climbing out of Earth's gravity well leaving us with a velocity of 55 km/s relative to Earth. It will take another 42 km/s to escape the solar system, so that would be a velocity of 13 km/s at escape. Voyager 1 is traveling at 17 km/s, so would either be ahead of it or will catch it eventually.
But this doesn't account for the earth's orbit at 30 km/s. So depending on the launch orientation to orbit, the manhole cover could either still be in orbit around the sun, or have a velocity of up to 43 km/s at escape. So it's possible, if it didn't get vaporized, that is.
The Wikipedia page has the date, time, and location for the Pascal-B test:
August 27, 1957 22:35:00.0, 37.04903°N 116.0347°W
So that would have been 10:35PM local daylight savings time from southern Nevada, so 9:30PM solar time.
Turns out the potential adder from earth's rotation is a negligible ~0.37 km/s at that latitude. With earth tilted by 23.5 degrees, we have it launched 37-23.5 = 13.5 degrees away from the orbital plane. That seems smallish, so let's ignore that. Seems like the best time would have been around 6AM to add to the orbital velocity and 6PM to be about the worst, subtracting off the orbital velocity. At 9:30PM, our 55 km/s launch vector is 127.5 degrees (8.5/24*360) away from the 30 km/s orbit vector. For a combined velocity of around 43.8 km/s. Check my math.
I'm missing something from the initial calculation which is that the solar escape velocity from the current position of Voyager 1 is about 3km/s, so Voyager's velocity at escape would be 14km/s, not 17, which is very close to the 13km/s of plumbob without any earth assist. So basically anything in the direction of orbit beats voyager, and anything the other way loses.
Looking down on the north pole, the earth rotates and orbits counter clockwise. This means that anything from midnight to noon will be aligned with the orbital vector and anything noon to midnight will be offset. 930PM will be about halfway between sunset and midnight, so losing 11 km/s from orbital velocity sounds about right.
It's almost certainly the farthest one, period. Voyager utilized multiple "gravity slingshots" to accelerate to a vastly faster velocity than we could achieve with rockets alone.
Yea but we don’t know how many failed attempts there were that got stuck at zero. We only know our one existence. Could be trillions of dead universes before ours.
Yes really. These improbabilities are guesswork, and their size is unknown. We know a spacefaring civilization has happened once, so the probability is far greater than you allow, and time obviously sufficient.
It is clearly possible to have a space-faring civilization, we’ve seen one. But the density could be extremely low. Fine, in infinite space we’ll get an infinite number of spacefaring civilizations whatever the odds. They exist, we just might never interact if the density is low enough.
But, I’m not sure, maybe it is a philosophical question or maybe it is a physics one (I only had an engineering education so at the extremes these get hard to distinguish sometimes). Does the universe outside of our light cone “exist” in some sense? If not, then I guess the universe is not quite so big.
Further, you might suppose that the planet needs to be in some reasonable band, in terms of power being absorbed from the star, to be amenable to life. And that, in order to hit spaceflight, you’ll need to have accumulated a certain amount of energy (for rocket fuel). This could bound the beginning of space-flight-viable planets to those which have already had a good amount of life for a couple hundred million years.
So this would seem, to me at least, to limit our universe of possible planets to those that are more than a couple hundred million years old, at least, in our frame of reference, right? (and this is assuming most of the Precambrian was a waste of time that could be skipped through lucky evolution).
I asked myself this same question when New Horizon sent pictures of Pluto back. I was surprised to learn that NH will never overtake Voyager because of the number of gravity assists Voyager 1 achieved. The planners had to race to achieve the 4 gravity assists in the 70's, the next time the 4 giants line up in such a way isn't until 2145. Perhaps some form of ion engine, one day, will help us overtake Voyager. Or more sci-fi fusion/nuclear rockets. Who knows, but it's interesting to ponder.
I find it interesting how they use “aging spacecraft” and “exceptionally long lifespans” of these devices. In terms of the age of the universe, or the time that light from a star has travelled to us, it’s minute. Aging in relation to human life maybe.
Ok so it says online it’s going at almost 40,000 mph so what is stopping us from sending one at say 400,000 mph, then couldn’t we catch up with it eventually? and travel the same distance in like 5 years?
and do what? at that speed, all you'll be able to do is wave as it sails by. you're not stopping at anything at that speed. however, even at 400k mph, that will not reach the next anything of interest before humans are extinct.
It's a shame deep space probe budgets aren't useful towards war on other countries or population-wide domestic surveillance or we'd have spacecraft at 10% the speed of light already.
Is there any chance we can zap its general direction with a radio beam and then listen with a huge radio telescope to get an accurate radar fix on where it is?
I mean, even if they can't recover it at this point, it's still been far more reliable and useful than any program I've ever written or hobby electronics project I've built. Along with Apollo it's really a testament to the phenomenal productivity of American science in the 50s, 60s, and 70s.
NASA tech often seems to outlive its initial mission length by a massive margin. The Mars rovers spring to mind. It's incredibly impressive, and almost embarrassing! Surely this isn't accidental. Is the kit massively over-specced? Do the uncertainties and risks necessitate such a depth of redundancy that when stuff goes kinda smoothly the thing lasts 9 times longer than it was designed to? Is it a political thing: they set their success criteria low just in case something goes wrong, but actually intend a much longer lifespan?
Sorry if this seems an incredibly cynical way of looking at the world. I actually love all this stuff - I'm just curious if there is a pattern here and what the reason is if so.
In addition to what other people mentioned (if you design something to have a 99.99% chance of lasting x years, it'll probably last some multiple of x), a lot of failures follow what's called a bathtub curve (visual depiction: https://en.m.wikipedia.org/wiki/Bathtub_curve#/media/File%3A...).
Once you can make something work for 1 day, you're past the most dangerous phase.
NASA definitely does overengineer things at the beginning, but it's worth noting that an incredible amount of work goes into keeping these things alive past their end date. For example regularly updating the software to be more efficient so probes can keep functioning and communicating despite having less and less power and being further and further away.
There's also lessons learned once a mission is in progress, like "if we move in this weird pattern we can shake some dust off the solar panels."
Finally, a lot of these missions that continue long past the predicted end date do so with some limitations - maybe going forward a particular sensor is unavailable or certain maneuvers can't be done anymore - but there's still enough to justify keeping the mission going.
If you design so that it has a 99.9999% chance of working for 5 years it's going to work for much longer. It'd be very hard to design it in a way that it didn't.
Overengineering is building in buffers that you didn't actually need. But it may be much later when anyone can prove it.
See also the roman aqueducts. Today we would have used about half as much stone, and they'd be falling apart in our lifetimes. Instead, lucky chunks of them have lasted 20 times as long as anyone ever could have expected to need them.
Designing things such that they don't require/ use steel reinforcement goes a long way towards having a (potentially) indefinite lifespan.
Reinforced concrete and masonry design are underappreciated disciplines of modern engineering, but their Achilles heel is that reinforcement rusts, rust expands, and expansion ruptures. All at relatively accelerated speeds.
Things like the aqueducts weren't necessarily overengineered, they were just designed (mostly) without quickly deteriorating elements, like steel.
Which is to say, 2000 yrs ago, the design of an aqueduct with a 10yr lifespan didn't differ much compared to a hypothetical one with a 100yr or even 1000yr lifespan. At least compared to how things would be done today.
Much of space design seems to be similar, where the minimum requirements aren't that far off from what seems like excessive engineering. But that doesn't necessarily mean anything was "overengineered".
And even if you design everything so it has a 75% chance of working for 5 years, some of the things won't last 5 years, but you'll still only hear about and remember the ones that work for much longer.
But a large part of the cost is not just construction but testing and verification. Not only that it does what it needs to do, but that it survives launch without destroying itself, survives being in a vacuum etc.
Most of that testing is specific to how each individual item was manufactured, so there's little cost saving if any to be had there.
Then there's the price of the launch, and the time on the radio dishes to follow them.
That's actually part of the thinking behind the "faster, better, cheaper" (FBC) policy of NASA in the late 1990s / early 2000s:
The intent of FBC was to decrease the amount of time and cost for each mission and to increase the number of missions and overall scientific results obtained on each mission
That was something of a mixed bag: numerous missions did succeed and returned phenomenal science, but there were also some spectacular and humiliating failures:
In 1999, after the failure of four missions that used the FBC approach for project
management, you commissioned several independent reviews to examine FBC and
mission failures, search for root causes, and recommend changes.
(Both quotes from the transmittal letter for NASA's 2001 report on the policy, as subsequent sentences.)
It turns out that space is an unbelievably unforgiving environment, and attempting to perform repairs, maintenance, tune-ups, and/or mitigations at distances of hundreds of millions or billions of kilometers, often at the end of hours-long round-trip speed-of-light lags, is challenging at best.
At the same time, FBC mitigated risks, and some of the problem may well have been a failure to manage expectations: with FBC, some missions would succeed, whilst others would not. But even in that context, gambling losses on $150 million bets remain painful. (It's worth considering that there have since been numerous failures by other nations attempting various space missions, this isn't a failing of the US alone.)
It's also worth considering that earlier missions, notably Apollo & Skylab, suffered numerous critical incidents, one fatally catastrophic (and that on the ground), but any one of which could have resulted in total mission losses, including lighting strikes on launch, computer failures on Lunar landing (Apollo 11), wiring-induced oxygen tank explosion (Apollo 13, resulting in abort of the planned landing), and failure to deploy Skylab's solar panel and sunsheild. People tend to remember the major incidents of Apollos 1 and 13, but not the numerous other close calls. The US Space Shuttle programme similarly had two catastrophic failures but each occurred within the context of numerous other close calls. The envelope for both error and deviance is vanishingly thin.
Since the early 2000s, NASA have modulated their approach to FBC. Some missions, such as the JWST, are absolute monoliths and relied on extensive and expensive testing and development, which has paid off with absolutely flawless execution of launch and deployment and truly universe-expanding insights. Others, such as the Mars rover programs, have iterated on concepts starting with small, cheap, and simple rovers of limited range to incorporating a "technology demonstrator" in the form of the Ingenuity heliocopter which accompanies the SUV-sized Perseverance rover. The Huygans lander (part of the Saturn-based Cassini mission, landing on the moon Titan), and Galileo probe (part of the Galileo orbiter mission) both rode along with and extended orbiter-probe missions to provide actual contact with planetary or lunar atmosphere and/or surfaces.
More on FBC:
"'Faster, better, and cheaper' at NASA: Lessons learned in managing and accepting risk"
On a real note, it is hard to do accidentally, but very much possible to do on purpose - so much so that it is currrently a driving factor of our evonomies.
I think it's not so much a question of deliberate overspeccing, but more that each of these missions is its own prototype. You're asked to design something to do a small part of the task, but you won't get a chance to try again if it goes wrong. You really really don't want your part to be the reason the mission fails. And you don't get to test your part in the real deployment environment and find out everything you need to know before your design the production part. So you have to design for every eventuality you can foresee, and then add some margin for the events you cannot foresee. So even if the spec is exactly right, to ensure you satisfy the spec first time with the uncertainties of the production environment, you end up producing a part that has as much margin for error as you can get away with in the mass and financial budget. Everyone involved does the same thing, because no-one really knows what the production environment will be like, and no-one wants to be the reason the mission fails. And so you end up with a spacecraft that is as overengineered as possible given the budget, even if it isn't specced that way.
The game is, if you get funding for X years, but you can remain on mission for X+N years, you have an opportunity to get easy funding after your initial funding runs out.
That's a major incentive to over build things. Engineers also love making things better, so, your workforce is defacto onboard with that mission.
And then, there's the issue that, basically every long term mission to space requires bespoke spacecraft. That makes things very, very expensive, but also, presents a requirement to engineer your way around unknown mission requirements. They know what they want to do, but, they don't really know how it'll work in reality. They can test some things, sure, but it's impossible to know every variable.
For instance, you're building a bridge with a 100ft span that's 50ft above the ground at the highest, in an area with a maximum wind speed of 50mph, and a maximum load capacity of 2000 tons of traffic moving 65mph. Now, that's basically enough information to build that bridge.
Now imagine that, you're asked to build that same bridge, but, you don't know how fast the traffic is moving, that's more difficult. Now, in addition to that, you don't know how much wind loading you have to deal with, more difficult still. Now imagine that, your load capacity isn't certain either.
Could you still build the bridge?
Of course you could, but, you'll have to build it with what you think are reasonable requirements. You might do some research into those requirements, but you also might not be able to. Where you end up is, the bridge you build is going to be over built, likely by a significant margin, if you desire to build a successful bridge.
This is the issue with designing spacecraft, you have more questions about requirements than you have answers, and sure, we have more answers than we used to, and the available pool of knowledge has only increased, but many points of uncertainty still remain. Not an unusual engineering problem, we'll get there eventually. It was about 100 years of thinking for us to learn to fly at all, another 100 years to learn how to do it well, and there's still plenty of room for improvement. Space flight will be much the same, and eventually we'll have the space equivalent of the honda civic
I think it’s political. It’s untenable to tell the public that it will work for “15 years with a 95% confidence interval” and have it fail after 14 years. There would be congressional hearings.
But you must give a number, so sandbagging makes sense.
It’s the same thing with telling your wife when you’ll be home…if you say 7pm and it’s 7:05, you’re late and dinner is cold. But if you say 8:30 and it’s 7:05, you’re a hero.
Organizations always react to incentives and all of the above and more are probably at play.
The funding incentives are probably such that failure means leadership is hauled before political theatre and accused of wasting people's taxes Vs say SpaceX where it's let's blow up one more rocket.
The political situation also probably makes it infeasible to ask for or rely on long term program commitments (which is tied to scientist & engineer employment) but once the hardware is already in place, getting extensions is probably quite cheap and non controversial
All these probably incentivize a risk averse and over engineering culture. Of course that benefits science fans, so I'd say more power to them :-)
I guess the problem is lead time. You want overspecced because you get one shot every 10-20 years between design, launch windows and the all too present political angle.
There is certainly a political element, when they tried doing cheaper missions they had two failures in a row which was really embarassing, even though probably if they had stuck with it it would have still worked out cheaper than using the low risk approach.
Mainly though if you design a spacecraft to have a 99% chance of lasting five years it ends up with a pretty high chance of lasting 30 years.
Based on some JPL documentary videos, I recall the engineers involved intentionally over-specced the components on the hopes that the mission would be later extended to go further out into the solar system. Check out the JPL channel on YouTube. There is a video series about the different missions throughout NASA history. Its really worthwhile watching.
Trick I learned from an old wrench: overestimate time and cost, then when you deliver something in half the time and half the cost they'll think you're twice the mechanic.
I'm not sure that's what NASA does, but it certainly doesn't hurt their PR.
Some missions blow up on the launch pad, or fail to reach orbit, or are lost mid-flight, or crash on landing. I wonder if the average actual mission length exceeds the average expected mission length.
Voyager 1 is so far away that it takes 22.5 hours for commands sent from Earth to reach the spacecraft. Additionally, the team must wait 45 hours to receive a response.
I’m guessing “hotfix” commits don’t exist in this domain
I guess it is nitpicking, but I hate the word choice they’ve selected there. The “additionally” makes it look like the 22.5 and 45 hour problems are two different things, instead of the natural result of a round trip.
I don't think you should use the phrase "viscerally hyperbolic", I think it overstates the degree to which their comment communicates an excess of emotion. Instead, consider saying "I don't hate it, but I don't love it" to express agreement with the sentiment, but disagreement with the degree.
Perhaps the phrase "I don't hate it, but I don't love it" doesn’t fully encapsulate the nuanced spectrum of emotional response. Might I suggest employing "I harbor a moderate degree of equivocation regarding this matter"? It articulates a position of neither fervent advocacy nor staunch opposition, akin to balancing on the fulcrum of a metaphorical teeter-totter, oscillating gently between the poles of approval and disapproval.
Everyone's experience is subjective. Maybe they really hated it.
I also hate the wording, it threw me off for a few seconds and made me lose min train of thought until I realized the author simply doesn't know what the word "additionally" means.
I wonder if it was messed with in editing or something, like maybe they have a style guide rule against long sentences.
Anything to merge the ideas together would make it clear that it is just one phenomenon, for example.
> Voyager 1 is so far away that it takes 22.5 hours for commands sent from Earth to reach the spacecraft, and so the team must wait 45 hours to receive a response.
The NASA press release is written: "In addition, commands from mission controllers on Earth take 22.5 hours to reach Voyager 1, ... That means the engineering team has to wait 45 hours to get a response"
The CNN writing looks uncannily similar but without the same meaning. I'm not saying it's machine generated, but I won't say it isn't.
The transmitter on Earth can be massive with an enormous power budget. Sending from Voyager might be much more constrained: less compute to compress the payload, less power to send it.
The speed of light is obviously the same either way but it’s not obvious to me that the speed of a byte (error corrected, etc) must be.
>The speed of light is obviously the same either way
It's not obvious that it is :) We don't have any way to prove that it is the same, because every experiment to measure the speed of light going from A to B requires some light to go from B to A which cancels out any difference. We just assume that it is the same because we don't have any reason to believe it's not.
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I suspect you're using some plugin that's blocking cookies (whether they correctly detect that as EasyList or not). Due to that, it's possible that CNN can't store your response to their privacy popup and so they have decided to limit their liability by preventing access.
If this turns out true, it would be quite ironic: they can't show you a legally mandated cookie selector intended to increase your privacy because you're running a piece of blocking software that's intended to increase your privacy.
The opt-in is only required if they collect your information. If they take the default as opt-out then they don't have to show you any prompt and have no liability.
