Wednesday, March 11, 2009

Giving space junk a shower

What do you do when there's too much junk in orbit? One guy thinks we should hose it all down. Literally.
In the 1980s, Jim Hollopeter helped design rockets that shot into orbit. Today, some of those launchers are still cluttering up space, and he wants to wash them away with a rocket-powered water gun.


The volume of man-made space debris has grown so large that scientists say garbage now poses a bigger safety threat to the U.S. space shuttle than an accident on liftoff or landing. The International Space Station occasionally fires thrusters to dodge junk.

The problem hit home Feb. 10, when a defunct Russian military satellite smashed into an American one used for commercial communications, spewing shards across thousands of cubic miles.

The crash prompted Mr. Hollopeter to refine designs for a concept he had long toyed with: Using aging rockets loaded with water to spray orbiting junk.

His idea is that the extraterrestrial shower would gradually knock refuse down toward the atmosphere, where it would burn up, as would the launcher. The water would turn to steam.
Pretty cool idea. Just as cool as the concept of a gravity tractor.


AlanDP said...

Maybe I'm missing something, but wouldn't water immediately turn to steam upon being exposed to the vacuum of space? Before it's able to push anything anywhere? I don't see how this could work.

Albatross said...

I don't know. I am almost completely uninformed on the behavior of water in open space. I assume that it would freeze pretty quickly, but I really don't know much else. I know that carbon dioxide ice on the Martian poles sublimes when exposed to sunlight, turning directly from a solid to a gaseous state, so I guess water might behave differently than here on Earth.

It's an excuse to learn more, that's for sure.

AlanDP said...

I had always thought that in a complete absence of atmospheric pressure, such as in the vacuum of space, water would immediately overcome its vapor pressure and "boil," or probably really sublimate immediately.

I remember being taught in high school that water boils when its internal vapor pressure overcomes the atmospheric (external to the water) vapor pressure. One way to do that is to heat the water. Another way is to lower the atmospheric pressure.

Albatross said...

You may be correct. I missed out on that lecture in chemistry class. :-)