The Earth has become ringed by a trash dump, filled with decaying old satellites, broken bolts and burned-out rockets from the Cold War era, researchers reported Friday.
The more than 9,000 objects orbiting the planet are also breaking down and spilling fuel as they disintegrate, and the pieces are becoming so small that experts say they can no longer track them.
Even a finger-sized chunk of metal can obliterate a satellite in a collision, they said.
And the space-junk problem is only getting worse for those seeking to put up new communications satellites or Earth- studying spacecraft.
“It may be possible there will be regions where … the risks of being hit by debris are so high, you will not want to do it,” said J.C. Liou, a researcher with NASA in Houston and lead author of a paper that appears in today’s issue of Science.
Liou and his co-author relied on space-debris data collected by U.S. Air Force trackers who operate from a computer-filled room deep within Colorado Springs’ Cheyenne Mountain.
They also used computer models tested by University of Colorado aerospace-engineering professor Robert Culp.
For the new analysis, Liou asked what the situation in Earth’s orbit is likely to look like in the future, given the current number of objects and their tendency to break down over time.
Collisions between orbiting objects are relatively rare, he said, but will become increasingly common.
About a year ago, a 31-year-old U.S. rocket body collided with a piece of a Chinese launch vehicle that exploded in 2000.
Those collisions, and the ongoing erosion of material in space, create an increasing number of smaller and smaller pieces of debris, zipping around the planet at more than 2,000 miles an hour.
“When they get smaller than a pop can or so, they get too small to track and we no longer know where they are,” said CU’s Culp.
There is no solution to the problem, Culp said. At various times, people have proposed retrieving spent satellites and other material with space tethers or ion engines or by perturbing their orbits with lasers.
“They’re science-fiction ideas, fantasies that will never happen,” he said. The solutions are either too expensive or chance taking down operational satellites as well as the junk.
Instead, Culp, Liou and others advocate not making the problem worse by ensuring new spacecraft all have an exit plan, a way to return to Earth after they are no longer needed.
“And you work around the problem,” Culp said. “You launch in ways you’d rather not, you go to higher altitude or a lower one. There’s still space up there.”
Staff writer Katy Human can be reached at 303-820-1910 or khuman@denverpost.com.
