Well it is out of the box thinking, not sure how practical it is though. Sadly a paper on "Brane Craft" does not show up on The Aerospace Corp's website, although Siegfrieds work on cubesats does (https://www.google.com/url?q=http://www.aerospace.org/wp-con...)
One of my favorite "low cost / unconventional" de-orbit ideas was candle soot clouds. Basically a cloud of carbon black that is deployed in orbit, it coats objects that pass through it asymmetrically resulting in asymmetric thermionic emissions when exposed to sunlight, creating a small net impulse which pushes the stuff out of orbit. Not sure how you would prevent it from killing stuff you wanted to keep though.
As I recall the paper covered rotation (all space junk seems to have a rotational component) the energy comes from solar insolation which is always in a consistent direction relative to the orbital motion.
This is one of those things where I am not sure if I just don't understand the core concepts, or if the person talking to me is a complete nutter.
Isn't a 'brane' a mathematical object? Is there any basis in science for turning a physical 3d object into a M2-Brane?
At first read I thought he was just talking about a space probe in the form of a thin sheet that could propel itself in a novel way. Now I think he's talking about dropping the ship out of the third dimension.
Nope. They describe the propulsion quite clearly. It's solar panels and an ion drive. The material they are ionizing is a liquid stored between the two sheets.
I'm actually not so sure about that. Either put some non-blackness around a black circle, or (probably more interesting) obscure the black hole by the effects of its gravitational lens.
Today is the anniversary of the Vostok 1 launch, the first manned spacecraft. If anything will make it to the front page of Hacker news today it should be that.
The relevant Hugo winner has you & thousands of others uploading your personalities into on onboard "neural mesh", resulting in everyone calling it the "Brainship". An in-voyage accident due to forgotten space junk sends you somewhere unexpected in space and/or time. During the trip the onboard community fragments and develops in a petri dish of experimental post-corporeal societies that promptly go to virtual war over control of the craft. The Bra{in|ne}boat encounters strange new lifeforms, which by a series of loosely connected plot devices involving convoluted theoretical and/or fictional mathematics, enable one small motivated group on board to seize control and return the device to Earth, over the objections of another group. In the intervening thousands of years, humanity has evolved radically and is facing destruction due to techno-industrial political forces wielding unimaginable power. The inhabitants of the Brainevessel join forces and use the wisdom and/or alien friends they gained during their epic voyage to save humanity, and the warring factions are subsequently reconciled and redeemed. One faction stays behind to help humanity recover, whilst the other goes on an unspecified voyage back to the stars aboard the upgraded Mindyacht. The End.
"Space is big. Really big. You just won't believe how vastly, hugely, mind-bogglingly big it is..."
A lot of it comes down to things just being far apart. We're used to the surface of the earth - a 2D surface, but space is 3D. There's orders of several orders of magnitude more room and not a lot of objects in it.
Secondly, the orbits of these objects are tracked and in a database. It's a pretty easy task to check if your planned launch path comes near anything.
Kessler is overhyped. The lower half of low earth orbit isn't a problem because everything there falls to earth in a year or two unless it is actively keeps itself in orbit. Outside of LEO, there's massively more room, and massively less stuff. So the only area we need to consider is "high" LEO.
As a thought expiriment, consider the worst case - a hyper intelligent, pan dimensional being disassembles all spacecraft in high LEO. let's assume that's 1,000 US tons worth. ( I have no idea.) if these spacecraft pieces were spread into a sphere the size of the earth, that would be 1/40 billionth of a cm thick.
Since a sphere doesn't orbit, let's turn it into lethal 1cm cubes, all magically evenly distributed, orbiting at the same altitude, magically not colliding. That's one death cube every 4 square Km. What are the odd of flying a rocket through that layer? Pretty good actually. The layer is only certain death if you stay in it. We'd still have access to the solar system, geosynchronous orbit, and mid/low LEO even in the alien intelligence worst case Kessler syndrome.
( I have only worked this out on the back of a napkin. Corrections to math appreciated)
(I'm not an orbits expert, but I do work for Planet Labs, and we're sending up piles of cubesats.)
The actors puting objects up in orbit are trying hard to be good neighbours these days. Our cubesat missions are designed such that should we completely lose control over a satellite the orbit will naturally degrade and re-enter the atmosphere on a ~10 year time scale. Our hardware deployed from the ISS is gone in less than two years. It's my understanding that it is required of us (and most groups in general) to plan our missions such that they will naturally de-orbit within 25 years.
Not quite. It really depends on the shape of the orbit and density of the debris. It could be months, but it could also be decades to de-orbit naturally. Also, the bigger problem is that the amount of debris is growing faster than the decay rate [1] so the problem is getting worse over time.
It's amusing to see "LEO" referenced twice in one day on HN, where the first time it was mentioned earlier[0] someone confused it for 'low earth orbit' when the author meant 'law enforcement officer'.
I've long maintained that TLAs have become almost completely useless outside of extremely tightly scoped discussions. The namespace is just way too polluted.
Nice idea using them for clearing orbital debris, but the $1bn cost of doing it "conventionally" seems a reasonable price to pay for continued access to space.
If we don't do something, we will end up trapped on this ball of rock by lethal kessler syndrome.
Why isn't there legislation mandating that space operators tidy up after themselves?
Wait, stupid question, we can't get that right even on earth.
One of my favorite "low cost / unconventional" de-orbit ideas was candle soot clouds. Basically a cloud of carbon black that is deployed in orbit, it coats objects that pass through it asymmetrically resulting in asymmetric thermionic emissions when exposed to sunlight, creating a small net impulse which pushes the stuff out of orbit. Not sure how you would prevent it from killing stuff you wanted to keep though.