NASA Studies Satellite Collision Over Siberia
ROBERT SIEGEL, host:
Up in Earth orbit, flying debris from an outer-space collision could threaten some satellites and spacecraft. NASA is especially mindful of the danger posed to the International Space Station. NPR's Nell Greenfieldboyce has the story of a sort of celestial smash-up.
NELL GREENFIELDBOYCE: This crash involved two big communications satellites, each over 1,000 pounds. They collided about 500 miles up, over Siberia, spewing out two clouds of space junk. NASA spokesman Kelly Humphries says there have been a few previous space collisions involving small objects, but those were minor.
Mr. KELLY HUMPHRIES (Spokesman, NASA): This is the first hyper-velocity collision of two intact spacecraft.
GREENFIELDBOYCE: He says the agency is now assessing the risk that this debris might hit other things in space, including the Hubble Space Telescope.
Mr. HUMPHRIES: All satellites that are operating in, or passing through, lower Earth orbit potentially are at risk.
GREENFIELDBOYCE: So far, he said, it looks like the crew of the International Space Station is not in any danger. There's an elevated risk to the station, but it's small and within acceptable limits. The accident has left some experts asking: How could this happen?
Mr. JOEL WILLIAMSON (Former Director, Center for Space Stations Survivability): These are large, trackable satellites. We should have a very good estimation of exactly where they are at any one time.
GREENFIELDBOYCE: Joel Williamson is a space debris expert and former director of the Center for Space Systems Survivability at the University of Denver. He says the military tracks thousands of objects in space - from working satellites to pieces of space junk.
Mr. WILLIAMSON: You can track anything that's a little bit larger than a softball.
GREENFIELDBOYCE: And satellites should be able to maneuver out of the way if there's warning of a possible collision. In this case, one of the satellites was non-operational - an old one owned by the Russian government. The other was owned by Iridium, a private satellite company based in Maryland. In a written statement, Iridium said, this even was not the result of a failure on the part of Iridium or its technology.
A corporate communications director would not talk on tape. But in emails, she said the company continually monitors its satellites and constantly takes actions to avoid other objects in space. But they didn't have advance warning that the collision would occur.
The military says its first indication of a potential problem came when Iridium reported that it had lost contact with the satellite. Navy Lieutenant Charlie Drey is with public affairs at the United States Strategic Command. He says the military does track objects, but they don't have the resources to analyze collision possibilities for all objects, all the time.
Lieutenant CHARLIE DREY (Public Affairs, United States Strategic Command): When we see something, you know, we will try to notify people so they can take the appropriate actions.
GREENFIELDBOYCE: But in this case, you all didn't see anything in advance?
Lt. DREY: No.
GREENFIELDBOYCE: The incident came just as space policy experts were meeting in Austria, at a subcommittee of the United Nations Committee on the Peaceful Uses of Outer Space. Brian Weeden is at the meeting. He works for the Secure World Foundation. He says the accident has been a big topic of conversation during breaks.
Mr. BRIAN WEEDEN (Secure World Foundation): It's a mixture of surprise and a little bit of inevitability.
GREENFIELDBOYCE: He says as space has gotten more crowded, people have talked about the need for some kind of air-traffic control for space.
Mr. WEEDEN: But we're still a long ways off from getting any kind of international agreement on what those rules might be and how they might be implemented.
GREENFIELDBOYCE: He says orbital debris mitigation was already on the meeting's agenda. He thinks this week's event might change the discussion.
Nell Greenfieldboyce, NPR News.
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