Interplanetary Landfill

It’s time I explained something about garbage.  Not just any garbage, mind you, space garbage.  Every satellite, manned spacecraft, and missile ever launched since 1956 has left, in some way, some debris in orbit.  From tools, and bags dropped by astronauts, to shattered remnants of weapons tests and collisions.  The problem has been recognized as a real threat to space travel for quite some time, but little has been done to address the problem (other than monitoring). 

Space junk is such an issue it has its own webpage, Wikipedia article, and an entire division of NORAD devoted to the problem.   Unlike the scene in Wall—e where the spaceship busts through the crowd of satellites surrounding the earth, the situation is far more serious.  Satellites don’t just sit still in orbit.   They travel tens of thousands of miles per hour.  In an earlier post, I showed a video of a car hitting a wall at over a hundred miles an hour.  A collision in orbit is 10,000% worse.  Even a small object can cripple a satellite, or destroy a space station.  The ISS (International Space Station) has to routinely alter course to avoid floating debris.

Image credit NASA

The problem isn’t getting any better.  Every month there are new satellites launched into various orbits, on various missions, by an increasing number of countries.  Not every launch is successful, and not every country cares about the debris left over (I’m looking at you DPRK and China). 

This isn’t ordinary junk.  It isn’t plastics, spare tires, Bart Simpson dolls, or unused AOL floppy disks.  Satellites are generally made of expensive materials in order to resist the harsh conditions of space.  This means a lot of gold, copper, aluminum, silicon, and rare earth metals that comprise electrical circuits, and the shielding necessary to keep them from shorting out during solar storms.  There are power systems, which can include solar and nuclear sources, and fuel for guidance systems to keep the satellite in the desired orbit.  Satellites are NOT cheap.

The greatest problem confronting scientists right now is how to deal with the problem.  DARPA (the Defense Advanced Research Projects Administration) has been looking at solutions that involve robots, lasers, nets, and automated spacecraft to collect the ever increasing trash, and get rid of it (either by recycling, moving, vaporizing, or returning).   Described in this Mental_Floss article.

The solution isn’t as easy as it sounds.  Remember the debris is moving rather quickly (17,000 mph +) and that contacting said debris in the wrong manner could, as I said earlier, cause significant damage to the spacecraft, if not the debris.   A simple case of this was a weapons test by China in 2007, where they destroyed a satellite using a “kinetic kill vehicle”.   The resulting impact shattered both vehicles into over 150,000 pieces with over 2,300 of those pieces larger than the size of a golf ball.   

Lasers would move the debris out of the way instead of vaporizing it, because blowing the junk up only adds to the problem.  I’m not a fan of this because: 1) it’s wasteful (throwing away gold makes no sense), 2) pushing our junk further into space, is just polluting the entire solar system instead of just our earth moon system.  

I’m also not a fan of capturing the debris and then vaporizing it on re—entry, because we’re just back to throwing away gold.  On top of that, we go through the expense of launching the retrieval vehicle into space.  

Using a single use capture vehicle to go after one bit of space debris at a time would take a very long time somewhat address the issue.  Remember there are hundreds of thousands of individual bits of junk up there.  This method would return the debris, but be a very expensive remedy in the end. 

Obviously, the problem is a complex one, and that no one solution will work in all cases.  It’s also not a problem limited to the United States.  This is a global issue that needs to be addressed sooner, rather than later.