Orbiting Debris collection
Since early this year, when the Russian Cosmos collided with the Iridium33 satellite and created two huge debris fields spreading around the globe, the issue of orbiting space debris has become openly serious.
Unfortunately, it is going to be hugely expensive to clean it up, and involve a serious amount of risk.
There are three different solution options, for 3 different types of debris.
1. For defunct, intact satellites, such as the Russian Cosmos, there will have to be individually targeted, one-shot "Space Tugs", that are sent after specific satellites, attach to them, and then, with their own dedicated rocket fuel and navigations systems, safely de-orbit the offending satellite, or send it into a safe parking orbit. As it may become possible to have lively cis-lunar economic traffic someday, the preferred method will involve de-orbit. For entire defunct satellites in GEO, there will be arguments that it would be cheaper to raise them out of the way to a parking orbit, but that would put them in the way for cis-lunar development. I suspect there would need to be a liability insurance rider involved, if the parking orbit alternative was chosen. If, at some time in the future, cis-lunar traffic did develop, and the parking orbit became a problem, removal would be paid for by the insurance.
2. For very small LEO debris - paint chips, nuts and bolts, little shards of insulation and stuff, Earth based lasers could theoretically target the debris and vaporize bits of it, causing it to change orbit and de-orbit. That's the theory, anyway.
3. Send a collection vessel up to sweep up bits of debris, and after collecting groups of debris, deorbit the entire collection vessel.
This is the most economical, but carries the biggest risk. The debris is traveling at orbital speeds - 17,000 mph, and if it impacts part of the vehicle not involved with collection, it may make the collecting vehicle explode, or damaged, creating more debris than it collected.
Consider the debris fields from the Cosmos/Iridium collision. You could, actually, insert a collection vessel into the orbit at approximately the same velocity, and collect debris at differences of only a few mph (or kph). The problem is, that much of the debris is spinning wildly, and if you manage to match orbit with it, you would still have several kilograms of mangled bits of sharp metal, rotating like a buzz saw through your collection vessel.
I think the design would have to involve an inflatable sphere of several layers of padded Whipple shields, with internal baffles and an internal interwoven series of arresting cables, to contain any buzz saw momentum affects. Several of the internal sections would have to be free-wheeling, in order to absorb the oddball momentum no matter what direction it tried to impart. If the internal collection spaces could, it would be a good idea to turn directional momentum into rotational momentum, so the entire collection ship wasn't knocked off its vector.
Unfortunately, it is going to be hugely expensive to clean it up, and involve a serious amount of risk.
There are three different solution options, for 3 different types of debris.
1. For defunct, intact satellites, such as the Russian Cosmos, there will have to be individually targeted, one-shot "Space Tugs", that are sent after specific satellites, attach to them, and then, with their own dedicated rocket fuel and navigations systems, safely de-orbit the offending satellite, or send it into a safe parking orbit. As it may become possible to have lively cis-lunar economic traffic someday, the preferred method will involve de-orbit. For entire defunct satellites in GEO, there will be arguments that it would be cheaper to raise them out of the way to a parking orbit, but that would put them in the way for cis-lunar development. I suspect there would need to be a liability insurance rider involved, if the parking orbit alternative was chosen. If, at some time in the future, cis-lunar traffic did develop, and the parking orbit became a problem, removal would be paid for by the insurance.
2. For very small LEO debris - paint chips, nuts and bolts, little shards of insulation and stuff, Earth based lasers could theoretically target the debris and vaporize bits of it, causing it to change orbit and de-orbit. That's the theory, anyway.
3. Send a collection vessel up to sweep up bits of debris, and after collecting groups of debris, deorbit the entire collection vessel.
This is the most economical, but carries the biggest risk. The debris is traveling at orbital speeds - 17,000 mph, and if it impacts part of the vehicle not involved with collection, it may make the collecting vehicle explode, or damaged, creating more debris than it collected.
Consider the debris fields from the Cosmos/Iridium collision. You could, actually, insert a collection vessel into the orbit at approximately the same velocity, and collect debris at differences of only a few mph (or kph). The problem is, that much of the debris is spinning wildly, and if you manage to match orbit with it, you would still have several kilograms of mangled bits of sharp metal, rotating like a buzz saw through your collection vessel.
I think the design would have to involve an inflatable sphere of several layers of padded Whipple shields, with internal baffles and an internal interwoven series of arresting cables, to contain any buzz saw momentum affects. Several of the internal sections would have to be free-wheeling, in order to absorb the oddball momentum no matter what direction it tried to impart. If the internal collection spaces could, it would be a good idea to turn directional momentum into rotational momentum, so the entire collection ship wasn't knocked off its vector.