What is it about this guy that allows him to make such claims and not be laughed out of the room? It's an amazing an useful talent that, oddly, I first witnessed as a young engineer on NASA's Hubble Space Telescope project.
The head of the servicing missions was a boisterous, outrageous, personality (some told me it was what held him from higher positions within NASA). He was the kind of guy who brought in a sales guy for a rapid prototyping machine (a 3D printer starting at $1 million), walked in half way through the presentation, and then promptly kicked the salesman out for not having a $200k offering.
He was also the kind of guy who demanded composite structures yielding 10X the mechanical properties of the current state of the art materials. But with no research projects, development, or anything even close to it. Just "get it done".
Of course, we didn't get it done (because it was impossible), but what we did get done was a major leap forward. We used materials without, gasp, flight heritage. We used the absolute state of the art in some cases. We got it done, it's just that it wasn't what was asked for, at least not directly.
This smells of the same thing. But don't underestimate the shear force of personality it takes to make such outrageous claims, and still have people follow you to something remarkable, yet more realistic.
If you want to build a ship, don't drum up the men to gather wood, divide the work and give orders. Instead, teach them to yearn for the vast and endless sea.
-Antoine de Saint-Exupéry
I think personalities like Musk are behind the above quotation. A dreamer with demands, and the demands are concrete in the respect that they may be technically possible while still being dreams - be they Mars at 500K or yielding 10x the mechanical properties. I think people are drawn to such personalities because it seems to be the most encouraging way you can possibly frame a dream.
If you want to build a ship, don't drum up the men to gather wood, divide the work and give orders. Instead, teach them to yearn for the vast and endless sea.
That quote sounds pretty awesome. However, in the real world that's not how most ships are built. There's a lot more "giving orders" than "teaching to yearn". It's not like the shipbuilding industry is famed for the dreamy yearning of its laborers.
I would say that he's got a fair amount of credibility now because he made his own space program. When you've made good on enough implausible claims, the criteria for "implausible" change.
This reminds me of Atlas Shrugged, when the entire community is against the stars for the book building the Rail Road. They don't believe it possible.
I would actually say, don't underestimate perseverance. Might sound like he is an optimist, but I think you have to be with anything to do with spaceflight. At least at this day an age. I would also consider him an expert in the subject, and what are you?
I think it's pretty cool that not only is he the obvious owner of the entire enterprise, but he is the chief technology officer because he is a self taught aeronautical engineer for lack of a better descriptor in this case. One of his degrees is in physics, sure, but one of his real ambitions in this instance is reading everything and talking to every expert he could in this field.
The point of the matter is that this kid did his homework and deserves everything he will earn in this endeavor.
There a couple of things that allow him to make these claims without being "laughed out of the room," as you say, but they don't have to do with his personality in the sense in which I take your meaning.
First, there is the rocket equation. That little gem tells us the amount of fuel it takes to achieve a given change in velocity for a given energy density of fuel. Then there are some results from orbital mechanics and aerodynamics that tell us what that change in velocity is. For the curious, escape velocity is just sqrt(2) times the circular speed at any given altitude.
I've laid this out before, but here it goes again. To put a pound of anything into orbit has a fuel cost of a little over $20. "Incredible!," you say, "It costs $10k/lb on the Space Shuttle! How can that be?!" Like so. Typical mass fractions are on the order of 2%. That is, 2% of the stuff on the pad, fuel, structure, payload, everything, actually ends up in orbit. About 12% of that mass is structure, things like tanks and engines and the like. That leaves 86% of the thing as fuel. 86:2 is 43:1. 43 lbs of fuel for every pound of payload. Assuming that propellant is roughly as dense as water and roughly the price of milk, both easily verified, that's under 6 gallons of propellant for every pound of payload, which will run you $21 at $3.50/gallon.
Multiply sqrt(2) by $21/lb and you have something like $30/lb. If you and your capsule weigh 2,000 lbs, That's $60,000 for a one way ticket. A little over 8 times that price may be a reasonable number. So, what makes up the difference in cost for current launch systems, or even for antiquated and clunky systems like the Shuttle? Low safety margins and their concomitant need for enormous administrative costs for each part, disposable launch systems where that administration cost burns up in the atmosphere or splashes down in the Pacific, and enormous system complexity driven by a lowest-flight-weight-results-in-the-cheapest-vehicle mentality.
We can begin to address, based on SpaceX's design philosophy and planned vehicle, how they may be able to make these claims without deserving to be "laughed out of the room."
First, SpaceX has reduced engineering and integration costs by reusing common components and simplifying designs at every step. they were (and I think, still are) using a pintle injector which is much less susceptible to catastrophic combustion oscillations than the more typical injector-face solution, at a cost of some performance. The tanks for all of their stages are the same diameter, allowing them to engineer and build one capital-intensive jig rather than two or three, and they get more experience with that hardware since all their work is done on it. They're using a pneumatic stage sep mechanism rather than a pyrotechnic one to eliminate material-handling, static, and other safery concerns related to pyrotechnics. Rather than relying on one or a few very large engines to power the first stage, they've chosen to use 9 smaller engines on the first stage and isolate each one in its own cato-proof container, again allowing them to gain more experience with a single system, prove its reliability, and leverage that experience and track record to perform a larger job.
Second, they have plans for full reusability of the launch system based on incremental changes to their existing systems. Yes, there is a fuel and performance penalty for going this route, but the savvy armchair aerospace critic will note that those penalties are expressed in tens of dollars per pound, whereas 100% disposal is measured in thousands to tens of thousands of dollars per pound. That is to say, even if reusability results in a 10-fold increase in fuel cost but allows vehicle cost to be amortized to negligibility, we're still approaching Musk's $500k/flight number. As to his actual plan, the fuel cost to land a booster segment is tiny compared to the cost of launching a vehicle. The first stage will simply reenter without having to retro-burn, and the second stage will need to retro-burn just enough to enter the atmosphere to achieve the rest of the braking. After that, the delta-v required is on the order of 100m/s, hardkly the 10km/s needed for orbit. You seem to know what you're doing, so I leave the derivation of that penalty, using the rocket equation, to you.
tl;dr: You're absolutely wrong in the most irrelevant way, and had you addressed SpaceX's achievements and plans in anything like a rigorous way, you could easily have answered your own question.
EDIT: The fuel cost for escape will not be sqrt(2) times the cost for circular speed. The real factor will be something more like 2 or 3, not 1.414... Still, we're in the range of $60/lb, not $6,000/lb.
So I was going to call bullshit on your price for rocket fuel given that regular gasoline is more expensive than this, but I looked up the price [http://www.desc.dla.mil/DCM/DCMPage.asp?PageID=722] and it turns out that's pretty close to the current price for JP-5. The most expensive fuel the DOD uses, JTS, is only $6/gallon.
Amortizing away the development and other fixed cost is cheating a little, no? I mean, we don't even know how to keep someone alive for the trip yet.
Reasonable people can disagree, but I wouldn't bet on Musk being alive to see the first successful round trip to Mars. But I also wouldn't bet against something truly amazing coming out of his activities.
He created a company from scratch that builds rocketships. A company that has launched a pressurized capsule into orbit. If his company was a country there would have been a human in that capsule and it would have made a lot more news than it did, as it was it still stands as an impressive achievement. And achievements give you a lot of credibility.
Impressive, but not sufficient to explain the power of his personality - which is enormous. For example, Orbital, a public company that builds rocketships, was also started from scratch by one man with a vision (and without the resources of Musk, I might add). And yet you've likely never heard of them.
There are lots of experienced, credible people who cannot do what Musk does with his outrageous dreams (and they are outrageous - to Mars and back for the cost of a upper middle class home in the US - think about that). To dismiss his impact as the consequence of success is to miss the true source, I suspect.
Robert Zubrin published a detailed plan for generating rocket fuel on Mars several years ago. His book "The Case for Mars" is a good read.
Such a technology really is a game changer for the economics of the mission. And you can send your robotic fuel factory and make sure it's working before you commit to launching people.
I've actually got that book in my collection and you're right, it is a good read.
The idea of producing rocket fuel on Mars is not only a good one, but quite likely the only way such a mission would even be viable. The idea of hauling all that extra rocket fuel for the return trip to Mars and back simply doesn't work.
While I'm sure it's a technical hurdle in itself, I didn't think that fuel or weight were the big problems with a manned mission to Mars. I'm curious as to what Mr. Musk's plan is for shielding passengers from intersteller radiation that one would experience outside of our magnetosphere.
The Apollo astronauts were exposed to approximately 1140 millirem over a 9 day mission, while the average here on earth is 350 millirem per year. Nuclear workers are limited to about 2000 millirem per year... so the approximately 52,000 millirem per year the astronauts would receive on a Mars mission is a problem.
We could be saved by the square-cube law, or, The Power of Being Big.
In essence, let's assume you've made your own fully-shielded space capsule for one, and that you need, for example, a pound of material for every square inch of its surface, and that you've made it into a sphere to economize on material. Wise choices, all of them. A 2m diameter capsule would come in at 19,500 lbs, or so, for that many square inches.
Congratulations. You've just found out why we don't shield small spacecraft. Now, however, let's get an estimate of what it would cost to shield 200 people, providing them each with a volume-equivalent of your capsule, or 4.2ish cubic meters per person. Really packing them in. This is a 11.6-meter diameter sphere, with roughly 3,300 pounds of shielding per person. At 2000 people, packed in like sardines, we're at 25.2 meters in diameter and 1550 lbs of shielding per person. A 54-meter sphere packs 20,000 sardines, and requires a mere 717 lbs of shielding per person.
A factor of 10-20 better. Obviously, we want to relax the space constraints a bit. However, the form factor of shielding in the larger craft is going to be much better suited to the reutilization of supplies as shielding. In the limiting case, of course, there is effectively no required shielding per occupant. Long before that, magnetic shielding schemes become a viable option, too.
A more practical limit would be to consider a transport module made up of re-entry craft seating 1-10 persons, with the ablative heat-shields and supplies facing outward. In this case, assume we can get down to 5 times your cross-sectional area in shielding, and guess that that's about 2.5 square meters. That's 4000/lbs per person. So, still a factor of 5 better than the solo case.
Additionally, this is a lot of arithmetic to ask of google and http://www.calculatorsoup.com/calculators/geometry-solids/sp..., so the numbers may be off. Also, the Dragon capsule checks in at 5.8 m^2 of heat shield per astronaut, which may be a practical limit. And I just made up the 1lb/in^2 shielding requirement.
Following that math, the 9 day Apollo trip got 0.0114 sieverts. We'll round that to 11 mSv.
So in 9 days, they got 11x more than the EPA's yearly limit to the public, or 1/5th of the EPA's yearly limit to radiation workers.
The 520mSv warpspeed listed as a trip's radiation exposure comes out to 5x the lowest yearly radiation exposure 'clearly linked' to increased cancer risk.
So yeah. A problem, barring adequate shielding, if that number is correct.
Where do you have that 52,000 millirem (i.e. 520 mSv) number from?
Doesn't that completely depend on the thickness and material of the walls of the spacecraft? I.e., isn't it just a question of making the walls thick enough?
I occasionally get to work with the Astronomical Society and have gotten into a few conversations about manned Mars missions with people from NASA, JPL and various educational institutions. The numbers are from a study NASA conducted at Brookhaven National Laboratory.
The problem with shielding is the weight involved to achieve any level of protection.. wrapping the ship in enough lead to make a difference would be hard to get it off the ground. Also while this type of shielding may be effective against normal solar radiation, high energy galactic cosmic rays are far more dangerous and are almost unaffected by conventional shielding.
If you're interested, I recommend this paper. It goes a bit deeper into exactly why radiation is such a problem for any proposed Mars missions (warning, PDF):
Good point, and would that would take care of the gravity well aspect of the issue. You'd still have the same amount of mass to accelerate, though. I suppose that wouldn't be as much of an issue once you weren't fighting Earth's gravity as well as inertia.
That's a silly argument. You could just as well say that the more things you launch that aren't a passenger-loaded vehicle, the more likely you'll have worked out the glitches by the time large numbers of lives depend on it.
A mission to Mars is guaranteed to be the most complex space mission ever attempted. Every additional rocket you need for the mission adds complexity. Complexity is the enemy of reliability.
What happens to your Mars departure window when the rocket carrying your life support system goes off course and is destroyed by the range safety officer?
Unless I'm missing something interesting (maybe a plasma shield?), this only works for radiation with an electric charge - protons, electrons, helium nuceli. Cosmic rays and other EM radiation are not affected by a magnetic field.
Cosmic rays are energetic charged subatomic particles, originating in outer space; i.e. they will be affected by magnetic field. About 89% of cosmic rays are simple protons or hydrogen nuclei, 10% are helium nuclei or alpha particles, and 1% are the nuclei of heavier elements. The term ray is historical as cosmic rays were thought to be electromagnetic radiation. [Quoted from Wikipedia]
I didn't read the whole paper, but your own link completely disagrees with your 52,000mrem/520sV-figure:
Whole body doses of 1 to 2 mSv/day accumulate in interplanetary space, and
approximately half of this value accumulates on planetary surfaces (Cucinotta et
al., 2006; NCRP, 2006).
That's millisieverts per day, not sieverts. Am I missing something?
52,000 millirem is 520 mSv, not 520Sv. This number is taken from the Brookhaven National Lab tests. The paper may be talking there about accumulated absorbed radiation, not total exposure.
Practically it really hasn't. Polyethylene is being tested in NASA's Radiation Shielding Program but I don't believe it's been put into service for a manned mission. There are also tests being conducted with adjustable "magnetic bubbles" that can in theory shield a spacecraft from radiation, but the last I heard they were done on a much smaller scale and would require a huge amount of power.
NASA has been making progress in making astronauts less susceptible to radiation damage through diet and vitamins. There's also this paper which talks about a vaccine that's being tested to counteract some of the body's responses to radiation exposure (PDF):
> Nuclear workers are limited to about 2000 millirem per year... so the approximately 52,000 millirem per year the astronauts would receive on a Mars mission is a problem.
The limits for nuclear workers are extraordinarily conservative, so it may not be as much of a problem as you'd think. Given the safety track record of manned spaceflight, the radiation is probably the least of your worries.
This might sound like a stupid question, but here it goes. What if you lined the astronauts in a room with a control unit and really thick lead walls for most of the journey?
Could this theoretically stop radiation, and protect them? Lead blocks most radiation, specifically gamma.
> A better solution is water. You need to carry it anyways.
You certainly won't be drinking that water after a while, though. Some might be used for cooling systems, but you would have a lot of extraneous water.
Why won't you drink it? Just because it's used for shielding doesn't make it radioactive.
Also water basically can't become radioactive. The isotope of oxygen with the longest half life, and more neutrons than the stable ones, has a half life of 26 seconds, so it doesn't stay radioactive.
If you manage to bind a proton (it's virtually impossible for oxygen, but lets say) and make fluorine, the result has a half life of less than an attosecond.
Deuterium is not radioactive, and tritium is hard to make (you need deuterium first, and there barely is any in your water).
The radiation could theoretically fission oxygen into other elements, but that's very unlikely, and the results have extremely short half lives.
In short: Water can't become radioactive, which is why it's so good as shielding. (However water can obviously be contaminated by something else that is radioactive - so don't go drinking the water in a nuclear reactor :)
How is he going to do the landing? Human manned craft are going to be too big for bags, and the atmosphere is too thin for parachutes to work. Landing on thrusters is somewhat fuel heavy (so to speak).
Your mass scales with the cube of linear dimension. Parachute drag scales as a square of linear dimension.
What this means is that the chute gets bigger much more quickly than the payload as you increase lander mass, to the point that you quickly get outlandishly large and impractical chutes for manned landers. Hence the research into alternatives.
I haven't gotten a chance to read the article yet, but is he planning on landing at all? I would imagine it would be much easier to just go there and back, without landing...? Much more fuel efficient and technically still "round trip."
He's relying on generating fuel on Mars, which considering that we've barely scraped the Martian surface with robots is highly speculative. Mars travel is still beyond business planning and into the realm of futures studies. I love SpaceX, but they haven't yet demonstrated they can reliably deliver payloads to Earth orbit on a regular basis. They're a long, long way from Mars.
I've heard some experts in the field say that the hardest parts about space travel are the launching and the landing. The middle parts, like the long boring flight and keeping the crew alive and not crazy, are massively easier and less risky in comparison, engineering-wise. They've shown they can put something into orbit. Landing on Mars with humans will be tricky, but the technology seems to exist to allow it, and that general kind of thing has been done before. Parachutes and thrusters, etc.
I don't doubt that SpaceX can get to Mars eventually, maybe even within 10 years. I really hope they do, I'm rooting for them. But I seriously doubt they will be ferrying space tourists out there for $500K apiece in any timeframe that would fit in a business plan, even a very long-term one. We're decades away from that kind of capability.
> Of course, there are many skeptical experts out there that have pointed out the fact that SpaceX has only attempted a rocket launch seven times. Of those seven, three were total failures.
Ouch. I hope that $500,000 is refundable in case of death or accident.
> Any human that makes the trip will be stuck inside the vehicle for the 214 days it would take to actually travel to the Red Planet.
I once made a road trip from Seattle to Tennessee in 3 days. In the middle of a frigid winter. During blizzard conditions. Of course we took breaks to get out of the car, stretch our legs, have a piss and get some fresh air. At the end of the trip I was ready to hang myself. The boredom and rigor of endless driving became unbearable. The prospect of taking a similar trip, over a much longer timespan, in much more hostile conditions and paying for the privilege is not appealing, at all.
To be more specific about their flight record: the first three test flights were failures, back when they were still working out the kinks on the Falcon 1. The flights since then -- including both Falcon 9 launches -- have been successful.
There is huge difference between traveling to places on earth and space and the motivation to do so. On earth you might be traveling for whatever boring reason.
Imagine if some one told you Shangri La actually exists and you have to bear some pain for an year to get there. What would you do? Will you take some pain to get there and live at Shangri La for some days?
Mars also has an atmosphere suitable for flying around in with helium or hydrogen balloons. You could mount a camera on a bunch of balloons and get some amazing pictures.
If you don't mind my saying so, "The view is better" doesn't sound like your real reason for preferring the moon.
The problem with Olympus Mons, when it comes to views, is that when you're on it, it's too big, and too gradual a slope to see off it. Also, when standing at the base of it, the summit is off over the horizon. Give me Valles Marineris any day.
So you can drop a half million dollars and spend 2 years of your life in a tiny compartment millions of miles from home to visit a dead, cold, rusty rock without a breathable atmosphere?
I expect there are many people who would find that very unappealing. I also expect that there are people who would put down the money right now if you would let them.
I don't find the idea of jumping out of a plane with only a parachute (that will probably open OK. maybe) to be appealing, yet thousands of people do it every year, willingly, and repeatedly. And that's downright mundane compared to the obvious exoticness and thrill those kinds of folks would get from setting foot on the planet Mars.
In other news, a one-way trip to Mars only costs $50k. If you don't make it, you can sue for a refund, but you have to sue in Martian courts, which won't be set up for a few more decades.
Is mars established as a credible planet/nation zone, or does it count as space (international)? Its an interesting perspective that the "zone" of mars could be a place of legal jurisdiction. But it seems that space is a free for all "zone", so maybe your lawsuit would be void?
According to the 1967 U.N. Outer Space Treaty, "outer space, including the Moon and other celestial bodies, is not subject to national appropriation by claim of sovereignty, by means of use or occupation, or by any other means. However, the State that launches a space object retains jurisdiction and control over that object. The State is also liable for damages caused by their space object and must avoid contaminating space and celestial bodies." (from Wikipedia)
So any crimes on Mars would probably fall under the jurisdiction of the country who launched the mission. Enforcement on the other hand might be tricky.
Interesting. I would imagine because of the vast majority of things that can come into contact with the vessel (ranging from a toothpick to an asteroid) could cause any amount of damage and there would be no way to retrieve the vessel for evidence.
I believe warpspeed meant damages caused to the celestial body BY the vessel, not vice versa. Basically they don't want you littering and damaging whatever planet/moon/etc. you decide to visit.
Hmm. Perhaps if the crime were committed in "that object" that was was launched. But what if it's outside that object, on the surface? Or within an object that was constructed on the surface?
Laws and treaties are just words on paper. They can be changed. They can be ignored. They have in the past and it's reasonable to assume they will continue to be in the future. So, I wouldn't rule out having some existing nation declare sovereignty over some part of Mars or an asteroid. They will give whatever excuse they need to justify it. Businesses would have powerful private profit incentive to be able to claim rights to things, and to have the protection of a patron national government's military to back it up, like the US, China, etc. We can also expect silly unnecessary wars to be ginned up by propagandists working for those same private profit interests. History is littered with examples, and no reason to expect it won't happen again in the future.
.jpg){kind=link}
The head of the servicing missions was a boisterous, outrageous, personality (some told me it was what held him from higher positions within NASA). He was the kind of guy who brought in a sales guy for a rapid prototyping machine (a 3D printer starting at $1 million), walked in half way through the presentation, and then promptly kicked the salesman out for not having a $200k offering.
He was also the kind of guy who demanded composite structures yielding 10X the mechanical properties of the current state of the art materials. But with no research projects, development, or anything even close to it. Just "get it done".
Of course, we didn't get it done (because it was impossible), but what we did get done was a major leap forward. We used materials without, gasp, flight heritage. We used the absolute state of the art in some cases. We got it done, it's just that it wasn't what was asked for, at least not directly.
This smells of the same thing. But don't underestimate the shear force of personality it takes to make such outrageous claims, and still have people follow you to something remarkable, yet more realistic.