Could harpoons be the answer to our space junk problem?
Space exploration is extremely important. However, it also means that there is some stuff in space that shouldn't really be there. This is a growing problem, and while we're a long way from a space landfill, space junk does put currently operational satellites and the like at risk. It isn't the kind of problem we can or should ignore, and one British engineer reckons the best solution to the problem is to take the junk out with a space harpoon.
The BBC reports that Dr. Jaime Reed, from Astrium UK has designed a barbed harpoon that measures 30cm in length and would be mounted on a chaser satellite. This satellite would take the harpoon to the junk, stopping about 100m away from the offending object. At that point, a camera on the ground would be used to position the harpoon for the perfect shot, and the satellite would move to just 20m away. The harpoon would then hook onto the space junk and it would be pulled (either via the satellite or a separate thruster) towards Earth, burning up on its way down.
The idea isn't perfect. For example, the BBC cites Dr. Reed as saying exploding fuel tanks in old rockets are a concern. However, the harpoon is still in the conceptual stages and there are other solutions on the table as well.
Further Reading
launching a harpoon at a hard object also seems a little off.... shards of metal floating free from each impact? using ground-based cameras to align the harpoon???
not giving this a high probability of success
Magnets are wonders.
But then I'm me.
F--king magnets...how do they work?
Something like a gas cloud might work. Create a cloud of gas in the path of the satellite by releasing something like liquid N2. It's soft enough that it might not create more space debris, and if it's dense enough it could perhaps slow the garbage satellite down enough to cause reentry. One large "cleaner" satellite could store several tanks of liquid N2, allowing it to clean up more than one garbage satellite.
One nice aspect of such an approach is that the decelerating gas quickly dissipates, leaving behind no additional space debris to impact other satellites on similar orbits. I just don't know if it's possible to create a cloud large enough to have the desired effect; especially with larger satellites, it might just change the orbit a bit instead.
Auxiliary rockets would do the trick. How else doe anything attach to anything in space? The space shuttle docked using rockets to position itself, a satellite can use rockets to negate the inertia from the harpoon launch. As for the idea as a whole, I'd like to see a much more efficient system than a 1:1 ratio for retrieving space junk...
seriously are all scientists on crack cocaine and using hemp for incense these days?