X-SciTech

Orbital Debris: A Growing Headache that's Getting Worse

By CBSNews.com CBSNews.com

October 26, 2010 / 10:21 PM EDT / CBS News

On Tuesday, astronauts aboard the International Space Station had to fire the craft's thrusters in order to move the orbiting lab and its crew of six safely away from a chunk of an old NASA research satellite.

Computer generated orbital debris graphics displaying currently tracked debris objects. NASA

It wasn't really a close call - this time - but increasingly, the ISS and other vehicles sent into low Earth orbit find themselves in the same neighborhood as a growing junkyard of space debris. (In 1996: a French satellite was damaged by debris left over when - paradoxically -a French rocket exploded a decade earlier.) It's estimated there are 19,000 objects larger than 10 centimeters and a half million objects measuring between 1 and 10 centimeters in diameter. Most of this debris is found within 2,000 kilometers of the Earth's surface.

According to NASA, this potpourri of stuff iincludes:

Derelict spacecraft and upper stages of launch vehicles
Carriers for multiple payloads
Debris intentionally released during spacecraft separation from its launch vehicle or during mission operations
Debris created as a result of spacecraft or upper stage explosions or collisions, solid rocket motor effluents, and tiny flecks of paint released by thermal stress or small particle impacts.

To make things that much more interesting for any manned missions, the orbital debris circling the Earth feature speeds between 7 to 8 kilometers per second. NASA notes that average impact speeds of orbital debris with another space object can reach around 10 kilometers per second.

Thus the urgency of getting out of the way of a small piece of debris, when possible. Often, that's not the case and a craft winds up taking a beating - as you can see in the accompanying image gallery.