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Boeing Proposes Using Gas Clouds To Bring Down Orbital Debris
cylonlover writes "Boeing has filed a patent application for a method of disposing of dead satellites and other debris orbiting the earth by hitting them with a puff of gas. The method, which is still at the conceptual stage, is designed to slow down satellites, forcing them to re-enter the atmosphere without sending up more space junk that itself will need disposing of. The idea is to send a small satellite into orbit containing a gas generator. This generator can be a tank of cryogenic gas, such as xenon or krypton, or a device designed to vaporize a heavy metal or some relatively heavy elements like fluorine, chlorine, bromine, or iodine. This gas would be released as a cloud in the same orbit as the debris, but traveling in the opposite direction."
Clever of them to patent this, since knock-off space-junk removal systems are in such high demand.
A space fart!
It's an apparently wholly new and unique method for doing something in the physical world. Why would it make them evil to patent that?
If the gas is sprayed at less-than-orbital velocities, it'd just fall to Earth almost immediately. Boeing in fact addresses that:
8. The method of claim 1, wherein the cloud is created at a density and temperature to dissipate after creation and fall into the atmosphere.
"None can love freedom heartily, but good men; the rest love not freedom, but license." --John Milton
Please do correct me if I am wrong, but this reads like a patent application that contains a novel, concrete implementation of an idea that isn't necessarily obvious to one skilled in the art. That is what patents are supposed to protect, and I have to say I have no problem with that.
It's perhaps the first /. post in a long time that contains a patent that respects both the spirit and the letter of what a patent is supposed to be. It also sounds fairly ingenious and very interesting considering the possibilities, so props to Boeing.
According to the patent application, "within second" for extremely LEO (100 km) and "tens of second" for slightly higher orbits (~400km). It'll depend on the exact application, but the proposal makes it sound like they intend the gas to be "stationary" relative to the Earth, so it'll be in free fall, basically. Other situations they propose put it at ~1km/s, where it will de-orbit rather quickly.
It is very very unlikely to cause issues. After all, we already spray gases around in orbit, it's the single method we have of propulsion, and I've never actually seen a single person worry that it will create long-term problems (although maybe it could, I very much doubt it).
Besides, it's a lot easier to deal with transient gas clouds slowing orbits than it is with ramming into shards of metal at 10km/s or more. Shards of metal with explosives in it, in (rare) cases of unburnt propellant.
"None can love freedom heartily, but good men; the rest love not freedom, but license." --John Milton
This reminds me of another method using light instead of gas, which was described at a recent space conference. The idea was to pulse laser light toward the west (since most space debris is traveling predominantly eastward), and over time the photons alone could provide enough delta-v to nudge things out of orbit more quickly. For the big stuff they have other plans in mind, such as electrostatic tethers and micro-rockets. But for little stuff, the light pulse would be a cost-effective "shotgun" approach to deal with the cloud of crap that's too small to track.
Sorry I can't find a link at the moment. I saw it a few months ago on YouTube from either NewSpace or SpaceUp, or ISDC or one of the other conferences in the last year or two.
XML is like violence. If it doesn't solve your problem, you're not using enough of it. --AC
Boeing:
LegendMUD
Actually, probably not. That's the beauty of this. Shooting gas at a satellite might cause some orbit degradation, but it'd be tough to do something really nasty to it. This only works against small pieces of debris, much smaller than any satellite. Which has, incidentally, always been the most worrying aspect of orbital debris.
Clearly the customers here are Governments.
One of the first orbits to be cleared would probably be around the ISS.
John Campbell of Iridium spoke at a June 2007 forum discussing the difficulty of handling all the notifications they were getting regarding close approaches, which numbered 400 per week (for approaches within 5 km) for the entire Iridium constellation. He estimated the risk of collision per conjunction as one in 50 million. Yet in 2009, less than two years after he made his prediction, his company lost Iridium 33 to a collision.
To date, there have been eight known high-speed collisions in all, most of which were only noticed well after the fact.
Sig Battery depleted. Reverting to safe mode.
Of course he's ignoring segments of the claims... You can't produce breathless hyperbole if you include all the facts.
Here's a quick summary of the procedure you're talking about: http://www.technologyreview.com/view/423302/nasa-studies-laser-for-removing-space-junk/
Initially, they were thinking of ablating the surface of the junk with the laser, but turns out you need a hell of a lot of power to do that, so it wouldn't be very economical. More recent calculations suggest exposure to a ~5kW laser might be enough to decay the orbit enough to bring it back into the atmosphere where it'll burn up, and they estimate that a device such as this, big enough to handle 5-10 objects a day, could be put together for a few million dollars.