CNN — A piece of space debris left over from a 2007 Chinese missile test collided with a Russian satellite earlier this year, rendering the satellite unusable, a researcher said Saturday.
The collision appears to have happened January 22. That's when it's thought a piece of the Feng Yun 1C weather satellite, which had been targeted in the missile test, accidentally hit a Russian satellite, said T. S. Kelso, a senior research astrodynamicist at the Center for Space Standards & Innovation.
"It changed its orientation in space," Kelso told CNN.
The collision also changed the orbit of the satellite, which was being used in scientific experiments, and might have damaged it, he said.
"There has been a piece of debris catalogued by U.S. Strategic Command as a result of that collision," Kelso said. "That would suggest that at least a part of the satellite broke off because of the collision."
It was February 4 when two scientists with the Institute for Precision Instrument Engineering in Moscow noticed a change in the orbit of the satellite, known as BLITS, Kelso said.
The scientists estimated the change happened January 22. They contacted Kelso because CSSI operates a service that looks for close satellite approaches, he said.
CSSI looked for objects that may have had a close approach with the BLITS satellite around the time of the collision. The Chinese debris was the only object they found.
Although the predicted distance between the debris and the satellite seemed to preclude a collision, the fact that the close approach happened within 10 seconds of the change in orbit made the Feng Yun 1C debris the likely culprit, Kelso wrote in a blog post.
CSSI is now working with the Russian scientists to find out more about the collision.
The Russian satellite is a small glass sphere that reflected laser beams for research. Because of the collision, the satellite now faces the wrong way and can't be used, Kelso said.
The collision also sped up the satellite's spin period from 5.6 seconds to 2.1 seconds, Kelso said.
China launched the Feng Yun 1C polar orbit weather satellite in 1999. It was destroyed in 2007 when China tested a ground-based, medium-range ballistic missile that rammed the satellite.
U.S. tracking sensors determined the missile collision created hundreds of pieces of space debris, according to a U.S. official at the time. The test prompted formal protests from the United States and several U.S. allies including Canada and Australia.
The problem of collisions involving space debris is not a new one. Scientists know of only a handful of such collisions, but that's only because they happened with objects that were being monitored from Earth.
"In this case in particular, it would have been very difficult to tell there had been a collision if it hadn't been for the fact that somebody was operating the satellite and noticed a collision," he said.
The last major space collision was in 2009 between Iridium 33, an operational U.S. communications satellite, and Cosmos 2251, a decommissioned Russian satellite, Kelso said.
It's likely there have also been "junk to junk" collisions involving unmonitored objects that no one knows about, he said.
"If nothing else, (this collision) was a bit of a reminder that it will likely happen again, and maybe we should get back to work trying to figure out what to do about it," said Kelso.