7 ideas to solve the space junk problem
— By Tyler Falk on January 14, 2014, 3:43 PM PST
For the near Earth space debris, launch rockets that release clouds of ionized particles in the paths of the offending items. We don't have to capture the junk, we just need to slow it down so that it falls back into the atmosphere. We could put linear engines on new satellites themselves, so they can accelerate or decelerate as they pass thru the ion clouds. Old junk would just decelerate from the friction and from the accretion of mass that is not actually in orbit.
To make this (and other space launches) less expensive, we need cheap hydrogen balloons to take the rockets to 60,000+ feet before they ignite. This would make a rocket launch much much less expensive. Hydrogen balloons are much cheaper and more efficient than helium balloons, and could be made safe enough for temporary use.
Today's rockets use most of their energy and mass to get out of the thick lower atmosphere. We had to design them that way in the 1950s and 60s because we did not have the computing power to compute the orbits on the rocket itself. Now that's trivial, especially with GPS available.
I agree that lasers are an ideal solution for garbage collection, but the aiming problem will be difficult if the "garbage collection" spacecraft is moving at high velocity relative to the offending debris. Not as difficult as using a net, but still hard.
Most of the proposed technology addresses whole appliances. As stated above, at least one third of the debris is in very small pieces - too small for retrieval by anything other than something like a net.
Unfortunately, to be effective for anything other than a whole satellite, the net would have to be enormous - beyond current technology, on account of how far apart the debris pieces are now.
These tiny pieces are also the hardest to track, but they are none too small to cause catastrophic damage to an operating craft.
It's not a good thing, and there should have been more international outrage than there was when the Chinese intentionally added thousands of pieces of debris to the cloud.
What the Chinese did was unforgivable. A virtual act of "space war". The first of its kind.
I don't think launching more hardware is the solution. As has already been mentioned here, deploying nets or similar solutions is questionable simply because most objects in orbit are not all in the same orbit, meaning that they differ in speeds by as much as tens-of-thousands of miles per hour. There are no space-worthy light-weight (meaning launchable) materials available that can survive those kinds of impacts intact without just creating even more debris, and contributing to the "cascade" problem.
I personally favor the laser approach, either ground, air or space-based. It's relatively low cost. Targetable objects can be nudged into orbits that would more rapidly decay, resulting in the disintegration in the atmosphere.
One of the problems with the junk is that it is in orbit, along with good satellites. So "sweeping" an area with nets is unlikely to be effective, since the net and the junk are traveling at the same speed. Putting the net into a retrograde orbit means the speed differential becomes so huge that the junk will break the net. Better would be to use a laser or something else to slow the junk down, so it falls back into the atmosphere.
@theotherwill The problem here can be reduced to one term: "Delta-V," which is the amount of energy required (and accumulated) to put a satellite into orbit. In order to retrieve a satellite (or anything else in orbit), a means to subtract that energy is necessary. In short, it takes as much energy and launch resources, to de-orbit as it takes to put it into orbit.
All the nets, etc. that we wish to put there to sweep the junk require a lot of rocket power, which is expensive.
@omb00900 That's hyperbole. "Space war" would be appropriate if the Chinese weapons damaged a foreign satellite or rendered unusable an orbital path that another country wanted to use. "Criminal vandalism" with financial & diplomatic punishments would be more appropriate.
@theotherwill@omb00900OK, I'll go with "criminal vandalism", but you might be splitting hairs. I wonder how many wars have been started over an act of criminal vandalism?
It was purely a political act, and there were no repercussions, which was my real point.