In the midst of ordering PCB boards for my satellite, I read about a neat UK
"CubeSail" satellite. It's a sweeper for space, to clear out all the space junk that we're cluttering low earth orbit with. It's basically a solar sail in reverse-- instead of propulsion, you use it to capture junk.

Now, this isn't needed for Project Calliope. We will responsibly biodegrade in the most natural way possible-- flaming burn-up as our orbit decays into the atmosphere. So we're tidy (and firey!)