LINDA WERTHEIMER, host:
This is MORNING EDITION from NPR News. I'm Linda Wertheimer.
Yesterday, two American astronauts and a Russian cosmonaut onboard the International Space Station had to briefly take shelter in an escape capsule. The danger they faced was a small piece of orbiting space junk. NASA was worried that it might smash into the station. NPR's Nell Greenfieldboyce has more.
NELL GREENFIELDBOYCE: The Earth is surrounded by space junk. Stuff like dead satellites, rocket parts, bits of paint. It's all whizzing around the planet at incredible speeds, like super fast bullets. If junk collides with a spacecraft it can cause real damage. Brian Weeden is an expert on space debris with the Secure World Foundation.
Mr. BRIAN WEEDEN (Secure World Foundation): Say you were sitting in the space station looking out the window. By and large you would not be able to see objects that were on a collision path.
GREENFIELDBOYCE: He says the objects are just moving too fast and coming from too far away.
Mr. WEEDEN: Their closing speed is almost more than really humans can kind of detect, especially for the ones that are really a threat for collision.
GREENFIELDBOYCE: But the military routinely tracts pieces of space junk that are bigger than a baseball. There's about 18,000 of them. Late Wednesday, NASA got word that something was soon going to come within three miles of the station. NASA says it was part of a spent rocket motor, about five inches across, traveling at a speed of roughly 20,000 miles per hour.
Kelly Humphries is a NASA spokesperson. He says normally they'd just move the $100 billion station to get it out of the way.
Mr. KELLY HUMPHRIES (Spokesperson, NASA): Because we got the notice so late we didn't have time to coordinate one of those maneuvers.
GREENFIELDBOYCE: So the next morning the crew was told to get ready. The astronauts closed hatches between rooms on the station, in case one was hit and lots air pressure. Then the crew went to the Soyuz spacecraft. That's a Russian capsule that's docked to the station. It's a kind of lifeboat.
Mr. HUMPHRIES: Asking the crew to seek shelter in a Soyuz is pretty rare.
GREENFIELDBOYCE: Humphries says the crew sat inside the escape capsule for about 10 minutes and waited for the piece of debris to pass safely by.
Mr. HUMPHRIES: We don't know, and probably will never know, how closely the debris actually came.
GREENFIELDBOYCE: Humphries says the bit of junk was not related to a dramatic crash in space that occurred last month. A large communication satellite collided with a defunct Russian one, spewing out a large new cloud of debris. But these recent incidents have put a spotlight on the growing problem of space junk.
Mr. BILL AILOR (Director, Center for Orbital and Reentry Studies): I think the more visibility you get to a problem like this the better.
GREENFIELDBOYCE: Bill Ailor is director of the Center for Orbital and Reentry Debris Studies at the Aerospace Corporation. He says people have proposed various ways to clean up the junk, but there's so much of it and it covers such a large amount of space that any cleaning effort would be technically difficult and also expensive.
Mr. AILOR: It's difficult to put objects into space, and similarly, it would be difficult to bring individual objects down.
GREENFIELDBOYCE: He says most experts think the best thing to do is just to avoid, as much as possible, putting any more litter up there.
Nell Greenfieldboyce, NPR News.
NPR transcripts are created on a rush deadline by Verb8tm, Inc., an NPR contractor, and produced using a proprietary transcription process developed with NPR. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.