5,500 Tons of Space Junk Orbiting the Planet

By RANDOLPH E. SCHMID, THE ASSOCIATED PRESS

WASHINGTON – More than 9,000 pieces of space debris are orbiting the Earth, a hazard that can only be expected to get worse in the next few years. And currently there’s no workable and economic way to clean up the mess.

The pieces of space junk measuring 4 inches or more total some 5,500 tons, according to a report by NASA scientists J.-C. Liou and N. L. Johnson in toay’s issue of the journal Science.

Even if space launches were halted now – which will not happen – the collection of debris would continue growing as items in orbit collide and break into more pieces, Liou said by telephone.

“On the other hand, we are not claiming the sky is falling,” he said, “We just need to understand what the risks are.”

The most debris-crowded area is between 550 miles and 625 miles above the Earth, Liou said, meaning the risk is less for manned spaceflight. The International Space Station operates at about 250 miles, and Space Shuttle flights tend to range between 250 miles and 375 miles, he said.

But the junk can pose a risk to commercial and research flights and other space activities. Much of the debris results from explosions of satellites, especially old upper stages left in orbit with leftover fuel and high-pressure fluids.