Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: Storm Steve on 27/07/2010 06:00:42

Title: Will Cubesats Increase the Space Junk Problem?
Post by: Storm Steve on 27/07/2010 06:00:42

In the Naked Astronomy podcast "The Biggest Questions in the Universe"
http://www.thenakedscientists.com/HTML/podcasts/podcast-transcript/transcript/2010.07.25-1/ (http://www.thenakedscientists.com/HTML/podcasts/podcast-transcript/transcript/2010.07.25-1/) there is a discussion about small satellites called cubesats. Cubesats are as small as 10x10x10 cm.

The suggestion was made that we should send constellations of tens or even hundreds cubesats into orbit.

My question is about space junk and satellite tracking.  There is so much junk currently in orbit that act as projectiles. The junk can destroy functioning satellites. Modern satellites must be able to evade the junk in order to survive. There are systems in place to track space junk.

Won't these tiny cubesats greatly increase this problem?

Thanks,
Steve

Title: Will Cubesats Increase the Space Junk Problem?
Post by: Soul Surfer on 27/07/2010 10:09:23

The problem is not so much the satellites themselves(which can be tracked and accounted for) but streams small particles caused by the destruction of or collisions between satellites.  Even a small flake of paint at a relative speed greater than a rifle bullet can be very destructive.

Title: Will Cubesats Increase the Space Junk Problem?
Post by: BenV on 27/07/2010 11:49:41

I asked this very question to Chris Castelli, but had to lose it in the edit as the interview was too long.  Here's a transcript from the unedited audio:

Chris Castelli:  They're very small and because they're generally put into a very low orbit, they eventually - naturally - de-orbit anyway.  Even though they may be 90-100km above us, there is actually an atmosphere there, and this does put drag on the CubeSats.  Generally, the CubeSats don't have any propulsion systems on board, so they eventually will decay, come back down to Earth and burn up harmlessly in Earth's atmosphere.

It's interesting you should bring up debris, because I think the University of Surrey are proposing to launch something called CubeSail which will deomonstrate a passive way of de-orbiting a satelite using a CubeSat platform as a way of quickly demonstrating the concept and the technology.  It will unfurl a large sail in orbit, and this, when it's positioned in the right way - into the track of the orbital motion - will actually put drag on the satellite and de-orbit it more quickly.  So they're looking at that with a CubeSat type platform.

Title: Will Cubesats Increase the Space Junk Problem?
Post by: Storm Steve on 28/07/2010 06:39:14

Thanks!

After reading the transcript my understanding is that CubeSats are usually put into a very low orbit, where there is little chance of collision with other satellites (that are generally at higher altitudes).

If CubeSats were put into a more "normal" orbit it would seem to be a nuisance to track (and avoid) hundreds of cannon ball sized projectiles.

Title: Will Cubesats Increase the Space Junk Problem?
Post by: palau on 07/08/2010 20:21:31

From what I know, there are CubeSat pico satellite in a 500 km polar orbit, so they will not come on Earth too soon.

Title: Will Cubesats Increase the Space Junk Problem?
Post by: peppercorn on 17/08/2010 18:53:05

I'd not heard of cubesats... Is this a cubesat?

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[;D]

Title: Will Cubesats Increase the Space Junk Problem?
Post by: cwinfield on 30/09/2010 21:48:13

The latest Kentucky Space CubeSat will test deploying a tether behind the CubeSat, increasing drag and meeting the NASA requirement of objects to be removed from orbit within 25 years of their launch.

Chris