d linkup of two station modules in 2000, before the first crew came on board.Slideshow: Month in Space
Russian news reports said Wednesday's maneuver was required to dodge "pieces of space debris" of unspecified national origin. ESA's news release stated merely that the debris came "from an old satellite." NASA's main station news page identified the threatening object as "a spent Russian rocket," but the more detailed daily report called it "part of the Kosmos-2421 satellite" (part of the payload, not part of the booster).
Launched in June 2006, the Cosmos-2421 was a naval surveillance satellite, designed for electronic eavesdropping to keep track of Western military vessels. According to U.S. tracking data, the satellite disintegrated on March 14 into hundreds of pieces — with further fragmentation on April 28 and June 9. More than 500 objects resulted, creating one of the largest debris clouds in space history.
In recent weeks, the station has been cycling through the thickest region of the debris cloud. "It's been giving us fits," said one analyst, who asked that his name not be used because he was not authorized to speak publicly. Although the peak concentration has passed, further avoidance maneuvers may yet prove to be necessary, another source told msnbc.com on condition of anonymity.
This type of Russian satellite has been observed to do this before, satellite watcher Jonathan McDowell told NPR in July. Because the initial breakup usually occurs within range of Russian space tracking stations, experts suspect that the Russians issue some sort of self-destruct command after the satellite's orbital mission ends.
Russian space officials have repeatedly denied that any explosion occurred.
In May, Alexei Zolotukhin, chief of the Russian Space Forces' information service, said the satellite had ended its mission but had not broken up, despite "unverified media reports" to the contrary. And in July, the Interfax news agency quoted Russia's deputy space agency chief, Vitaly Davydov, as saying he saw "no evidence for media reports that claimed, citing NASA, that a Russian military satellite had exploded in orbit and that its fragments threatened the international space station."
Davydov admitted that "there have been vehicles of this type in the past that exploded," but not this time. He blamed the rumors on Western spies: "For some reason, questions of this kind didn't arise in the years when this was happening. ... These days there are such questions all of a sudden. Our interpretation is very simple: there is certain interest in vehicles of this class that are used in the interests of our Defense Ministry."
But as Wednesday's rocket firing showed, Western interest in the satellite's debris cloud was entirely prudent.
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