Space Junk: Part II

Ok, so let’s assume space junk is indeed a problem worth devoting time and energy to solve. (Although at this point I wouldn’t label it as a “crisis”, even if it does meet some of the criteria we discussed in class, namely the fact that it represents a trend that radically deviates from historical trends.) What can be done about it, what should be done about it, and what is being done about it?

The NASA Orbital Debris Program Office has this to say about debris mitigation:
“Controlling the growth of the orbital debris population is a high priority for NASA, the United States, and the major space-faring nations of the world to preserve near-Earth space for future generations. Mitigation measures can take the form of curtailing or preventing the creation of new debris, designing satellites to withstand impacts by small debris, and implementing operational procedures ranging from utilizing orbital regimes with less debris, adopting specific spacecraft attitudes, and even maneuvering to avoid collisions with debris.”

That doesn’t quite sound like mitigation to me. The statement introducing the paragraph references the importance of controlling the growth of orbital debris, but except for the first measure listed, all the solutions listed are merely ways of dealing with a large (and growing) amount of junk. That sounds like mitigation of the effects of space junk, not mitigation of the problem of space junk itself.

Is this a problem that is best solved by adaptation or by reduction and elimination? Let’s assume, for a few moments, that we need to get rid of much of the abandoned, burnt out, used up, forgotten, useless, and lost hunks of metal and plastic as we can. There are really only two options for doing this: bring them down to Earth or send them further out into space.

But what about destroying them? Without sci-fi super-villain scheming, the conventional methods of blowing things up merely breaks up the guilty debris into smaller fragments, and micro-meteorites can be just as problematic as their toaster or refrigerator sized predecessors.

“Re-entry” is the polite name for bringing space junk back down to Earth. It has two forms: uncontrolled re-entry and controlled re-entry. Uncontrolled re-entry involves the inevitable orbit decay that accompanies the loss of the satellite’s energy followed by an eventual crashing down to Earth. That sounds fun, right? As the NASA Orbital Debris Program Office website puts it, “the surviving debris impact footprint cannot be guaranteed to avoid inhabited landmasses.”

Well, at least there’s comfort in the fact that 70% of the Earth’s surface is covered by water, and with the imminent threat of global-warming induced sea-level rise it’ll be easier to miss land if we start bringing dead satellites down in 50 or 100 years.

Of course, there are less hazardous ways of bringing large objects down to Earth from space. For example, the MIR space station successfully plummeted into the ocean without any complications. (You can read about the entire saga here on space.com.) Needless to say, despite the fact that no one got hurt people living in the South Pacific weren’t very happy about the fact that it was happening.

Sending satellites further out into space typically involves sending useless satellites to a “graveyard orbit.” This only postpones the plummeting to Earth problem. True, it will take hundreds of years for satellites in a graveyard orbit to lose enough energy to de-orbit and crash into the Earth, but it will eventually happen.

So, the two solutions to space debris (which, of course, only apply to satellites and spacecraft that have control and propulsion systems and not to the innumerable pieces of inanimate trash—here’s a breakdown of the space debris by type: operational spacecraft — 7%, old spacecraft — 22%, rocket bodies — 17%, mission-related objects — 13%, miscellaneous fragments — 41%) boil down to: not really that safe and reliable versus putting off the inevitable until another day.

I haven’t stumbled across any radical solutions, like making a spacecraft with a giant bulldozer-type shovel attached to it that scoops up all the trash and sends it into the sun or anything, but I’m sure people have tossed those around too.

And we've traversed another giant circle. Coming back to the real problem with this problem: not the difficultly posed by its geographic remoteness, but by its conceptual remoteness. Who really has time (or money, or effort) to worry about all the junk floating around in orbit when Tuvalu will be submerged within a century? I think that’s a challenge that mars the entire space program, especially with all of the looming “environmental crises” we’ve been discussing nipping at our heels.