by Doug Bernard for VOA Digital Frontiers Washington DC (VOA)
Dec 10, 2012 The amount of space junk floating around the Earth
grows every year, and increasingly can pose risks to spacecraft
orbiting the planet. In the United States, NASA's Orbital Debris
Program (ODP) at the Johnson Space Center in Texas, keeps an eye
on the ever-expanding junkyard of space. "We define orbital
debris as any man-made object orbiting the Earth that is no
longer serving a useful purpose," says Gene Stansbery, project
manager for the ODP. "That can be anything from very large
rocket bodies and dead satellites that are no longer useful, all
the way to very tiny particles that are eroded from the painted
surfaces of spacecraft or rockets, the entire size range." In
the weightless and friction-free environment of orbit, it's not
so much the size of all this junk floating in the Earth's orbit,
but also the speeds at which it travels, according to Stansbery.
"If you look at orbital velocities and the average collision
velocity, you're