When Space Gear Turns Into Space Junk
There are millions of bits of junk up there, and sometimes they fall to Earth.
JOHNSON SPACE CENTER, Houston, Nov. 25, 2008 — -- When astronomer Kevin Fetter spotted the bright object streaking across the sky, he had a pretty good idea what he was looking at: astronaut Heidi Stefanyshyn Piper's tool bag.
Fetter trained his telescope on the item and recorded it streaking across the sky. What was once a $100,000 tool bag is now just another piece of space junk.
The numbers are staggering: 13,000 pieces of junk larger than 10 meters are orbiting in space. There are at least an additional 100,000 pieces of orbital debris that measure between one and 10 centimeters, and the number of pieces smaller than one centimeter orbiting around Earth is in the millions. It's a mess up there.
What Is Dangerous?
Why does NASA care so much about all the space junk? It only takes one tiny micrometeoroid to punch a hole in the International Space Station or the space shuttle and that could cause catastrophic damage.
When an astronaut needs to throw something away on the space station there aren't many options. They can stash it and wait for a progress supply ship to take it away, or return it on one of the rare shuttle flights.
But when you have something really big you can't stash it in a supply ship.
Astronaut Clay Anderson shoved a big piece of hardware off the International Space Station in July 2007 during a spacewalk. The item was a coolant storage unit on the International Space Station -- an EAS, for early ammonia servicing unit. It weighed 1,360 pounds and it was big enough that no one at NASA made the decision to toss it overboard lightly.
The EAS finally re-entered Earth's atmosphere Nov. 3, and what was left of it splashed harmlessly into the Indian Ocean south of Tasmania overnight.
Fetter tracked the EAS as it came down from space.
Tracking Space Junk
The Department of Defense tracks objects larger than 10 centimetersand if it looks like something will come close enough to the International Space Station to worry flight directors, then Mission Control can initiate course maneuvers for the space station to keep it from being hit.
Deputy Space Station Program Manager Kirk Shireman told ABC News last year that NASA takes several factors into consideration before deciding to jettison something from the space station. NASA officials came up with a space jettison policy, which they hope will be a model for other countries flying in space.
Shireman said he asks himself several questions before he tosses something overboard: "Is it safe for the International Space Station? Is it safe for any other orbiting vehicle? Is it safe for people on Earth? Does it make sense from an overall problematic risk standpoint?"
The space station has a very colorful history of shoving items off into orbit. Remember SuitSat in 2006? SuitSat1 was an old Russian spacesuit stuffed with junk from the International Space Station, powered by three ni-cad batteries, and housing a ham radio transmitter. It orbited for a few months before it finally fell to Earth.
SuitSat was so popular with people who track space junk that the Russian Space Agency is considering doing it again.
Cosmonaut Panel Vinogradov hit a golf ball into space two years ago year as a publicity stunt for a golf club manufacturer. The golf ball stayed in orbit for a few days.
How long will Piper's tool bag orbit Earth? Fetter predicts it will take at least a year for the tool bag's orbit to decay enough for it to fall out of orbit and back to Earth.