[ScientificSorcerer (OP)]

There is a huge problem with the future of space travel, space junk.  It has gotten pretty darn bad. space satellites have been destroyed in the past because of random junk hitting stuff at high speed. No maned ships have been hit but the problem is just getting worse, more and more junk is piling up and only one mission plans do anything about it.

I don't know about you guys but the idea in the video just plain sucks in my opinion.
I think we'll need something like a big magnet to clump up all of that junk then hit the ball out of orbit.

it's probably not that simple but it's better then a dang crane machine in space.

[CliffordK]

I think we'll need something like a big magnet to clump up all of that junk then hit the ball out of orbit.

I doubt much of the space debris is iron based, so it won't be very magnetic.  You might be able to do something like an aerogel blob to absorb multiple small objects, but as they mentioned in the film, you may still need to speed and direction match the objects somewhat as a 10kps collision would be difficult to absorb.

The large objects are likely much easier to avoid than the small ones, but over time, uncontrolled collisions between large and small objects could make more small objects.

The one change I would do with the Swiss plan is that the "Janitor Satellite" should be able to redirect the captured object, then go pick something else up. perhaps absorbing propellant from the captured object, or energy from it when it is thrown out of orbit.

They didn't discuss the tumble rates, but I assume they will practice the capture with full size models on Earth before trying it in space.

[lean bean]

Does this idea seem mad today?
480 million copper needles to create a reflecting layer in space.
Project West Ford
http://en.wikipedia.org/wiki/Project_West_Ford

[CliffordK]

I wonder if the copper needles would be relatively easy to mop up using essentially aerogel blobs inserted into an orbit that crosses their orbit.  Solar panels might be a problem unless well protected as an impact to the solar panels would damage the panel, and likely add to the space junk.

Anyway, having a bunch of objects in a well defined orbit, all sharing a similar orbit, and I would think one could make a plan to capture them.  Of course, it may take decades to do, but no sense in just putting it off forever.

[lean bean]

 

he successfully allayed the fears exhibited by the vast majority of UN ambassadors from other countries. He and the articles explained that sunlight pressure would cause the dipoles to only remain in orbit for a short period of approximately three years. The international protest ultimately resulted in a consultation provision included in the 1967 Outer Space Treaty.

Status

As of 2008, several clumps of the needles are still in orbit, and occasionally re-enter.

from http://en.wikipedia.org/wiki/Project_West_Ford

That last part about several clumps remain, can they detect the single needles that remain if not in clumps?

And these two projects are ones we are allowed to know of.

Cliff

Anyway, having a bunch of objects in a well defined orbit, all sharing a similar orbit, and I would think one could make a plan to capture them.

Yes, making a plan is the easy part, lets hope the clean up missions don't become part of the junk itself.

[CliffordK]

I suppose there is a lot of second guessing in hindsight.  Had they put the needles in a 100 mile orbit, their orbit would have decayed as planned.  Why they put them in a 3500 km orbit is beyond me.

I hope the Swiss plan goes well, although it is a lot of effort for one piece of "debris" in an area larger than all the oceans combined.

I do wonder.  In the film they say the orbiting debris is traveling 7 to 8 km/s, but the collisions are at about 10km/s.  However, is that right?  Isn't all the debris orbiting either in the same direction (eastward), or north/south?  So I would think the collision velocities would be quite a bit less than the velocity relative to Earth of the stuff.

[Pumblechook]

If there are 20,000 objects over 5cm in orbit and given that the UK has an area 1/2000 of the Earth there will be just 10 objects over the UK at a moment in time and given that these will be at different heights the chance of two objects colliding must be very small.   

[CliffordK]

One would think it would be hard to run into anything in space.  But, in 2009, a US satellite collided with a defunct Russian satellite

Most of the satellites have been placed into either LEO, or geosynchronous orbit, and thus those two orbits also have the largest concentration of debris.

It might be safer to put more stuff into a medium earth orbit, but also more expensive to get there than to LEO.

There is discussion of the sandblasting effect of sub-cm objects.  Does hydrogen/oxygen rocket fuel make orbital ice pellets like orbital hail?