More on Orbital Space Debris 275
wvanhuffel writes "This is a call for /.'s to put their thinking caps on. The US Airforce, NASA and other agencies are looking for ideas to find and eliminate threats from space debris to craft (space, in the use of).
Personally I like the idea of "robots to serve as roving garbage scowls" - my question is "How do they identify 'garbage'?" - Would the ISS qualify?" I don't know what happened to the laser broom.
Sticky Umbrella (Score:3, Insightful)
Obviously this only works for grit and other small things.
TWW
Don't make it worse (Score:3, Insightful)
Re:Sticky Umbrella (Score:3, Insightful)
An collector in space is impractical (Score:3, Insightful)
Why launch anything into orbit at all? A far better solution would be to build a powerful enough ground based laser system to convert the garbage into vapor. It would be cheaper, as you would not have to spend vast sums of money trying to minimize failures (if the laser on the ground breaks, you get out tools and fix it. If the orbital robot breaks you just blew a lot of money). To detect the rapidly moving orbital debris you would need an extremely high resolution radar...at least one of the X band things being build in Alaska.
The laser would be an array of linear accelerators in parallel (or cyclotrons) that would accelerate electrons that would release the energy in the beam. (A free electron laser) Such lasers are inherently very efficient, and the system would only use electric power that could be obtained off an ordinary power grid (a LOT of electric power...you'd need some sort of temporary storage perhaps giant rotating drums or something)
And the best part? A multi-megawatt laser array, capable of hitting extremely small fast moving targets with enough power to vaporize them...
Certainly the Pentagon could think of a use for one of those.
Say, missile defense?
Such a system would be FAR more reliable than a rocket booster interceptor that has THOUSANDS of possible points of failure. If the wrong part fails, the booster fails. With a parallel array of lasers if one fails its no big deal. In addition, given enough power it would be able to vaporize all the incoming targets, decoys and bits of insulation and all.
Deja Vu, No? (Score:2, Insightful)
And before you get modded up further, small pieces of grit are capable of creating holes in the the space shuttle's windshield. [aero.org]
Re:Sticky Umbrella (Score:5, Insightful)
How about a large dish coated with a think layer of soft material which you put into an orbit you want to clean and after its been there for a while fire the retros and burn the lot up in the atmosphere.
For some reason, one thing I haven't seen people mention so far in this thread is the fact that to be in orbit at a given height above Earth, you have to be travelling at a very specific orbital velocity. So the umbrella either has to be going with the flow, in which case it's not going to catch up to any of the space debris (unless the debris has an eccentric orbit), or against the flow, in which case it is going to impact the space debris with a very high velocity.
I suppose a third option is to have it going with the flow, but faster than orbital velocity, in which case it's going to need a lot of fuel... (remember, a spacecraft has to eject balast every time it changes direction, otherwise conservation of momentum would be violated.)
-a
Ground based laser not practical (Score:3, Insightful)
How can you possibly believe that?
First, a laser on the ground would have to have a crapload of power since the vast majority of it would be dissipated by the atmosphere.
Next you have to refine the optics to an extremely high degree so that the beam is still focused at the target. Even the slightest bit of divergence really adds up over hundreds of kilometers. To vaporize high tensile strength steel requires a lot of energy, and most of these objects are very small -- both are reasons for needing a focused beam.
Also consider that they are traveling at tens of thousands of MPH. It would be almost impossible to servo track the object, so your laser would have to work with a single high-energy pulse. You'll need a very high peak pulse power to deliver enough energy to do any serious damage. And this ignores the fact that we can't actually track the majority of the debris. The ground based laser thing would need extremely precise tracking information which is just not available for anything but the large stuff -- which we can already do a fine job of working around. Also consider the aiming accuracy necessary to precisely hit a small target a few centimeters or smaller from hundreds or thousands of kilometers away. Then there's the issue of all the crap in the way between your laser and the target which could cause diffraction, scattering, dissipation, etc.
In the 80s the Star Wars thing was going to cost how many billions (75?) to disable (not totally vaporize as you propose) much larger objects traveling at more certain orbits, and was called a technical impossibility by many engineers who read the proposal. And even this plan would have used space-based lasers so the distances and dissipation factors was not as bad.
What you are proposing would never work. Get real.
what abou the space pen? (Score:3, Insightful)
When the obvious solution (used by the Russians) was to use a pencil...
I think that having this kind of question opened to anybody can only help...
Water Balloons To Save The World (Score:2, Insightful)
How about Nerf? But it might not be so "squishy" in a vacuum, particularly if the soft foam has volatiles which evaporate. But you just want to slow down an impacting object - if it embeds itself that's fine, but merely slowing it will also help the junk fall from orbit sooner.
A disc might not be the right design. Just a balloon full of honey or syrup. "This Orbit Clearance Service Uses And Paid For By Jello"
Actually, you'd need to use a material which is not too volatile. When exposed to vacuum the material should not boil away nor have the surface harden so it can not be penetrated easily enough. Not that an object hitting at orbital speeds will be easy to stop from penetrating...
There is an awful lot of empty space up there, so the odds of hitting anything is small. But if there is indeed a 1% chance of a satellite being destroyed in a year, there must be an awful lot of junk. A Space Shuttle can carry up a 15-foot by 90-foot cargo, which could create a rather large absorbent blob. Especially if you use balloons full of foam and create the foam from much smaller liquids, so the 15x90 volume gets multiplied to a much larger volume.
Collecting debris (Score:2, Insightful)
The bags could have a simple mechanical one-way opening, to avoid inertia to make things scape. The main criteria of (automatic?) selection would be the size, since most of the junk in orbit is small, and the main problem is this - big things are more likely to be avoided by spaceships.
Alex.
We have the technology... (Score:4, Insightful)
- into decaying orbits or
- a designated "trash ring" or
- push it to escape velocity
depending on specifics of each piece of junkFunny as it sounds, this could work. A proactive strategy would be based on using single hits over multiple targeting windows to push each piece of junk into decaying orbits or to shepherd junk into a trash ring where our grandkids could mine it (what will be the multiplier for the value of a chunk of scrap metal that is already at orbital velocity?). Beebees that miss would add an insignificant amount of water vapor to the upper atmosphere or leave near Earth space. Each shot would cost no more than the cost of the beebee-- the power is free. Someone could figure out the ratio of the size of the solar array to the number of shots that can be fired in month's time. My wag is that with collectors comparable with today's, the thing could manage a few shots a week.
A program like this would need a good name. I suggest "Space Balls"