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Original artwork by Windows to the Universe staff (Randy Russell) using images courtesy of Iridium Satellite LLC and NASA.
Satellites Collide in Earth Orbit!
News story originally written on February 13, 2009
In February 2009 two satellites in Earth orbit crashed into each other and were destroyed. This was the first time ever for a major collision between two satellites in Earth orbit.
The satellites were about 776 km (482 miles) above the ground when they hit each other. They were over Siberia at the time. Scientists think they were moving at a speed of about 11.6 km per second (26,000 mph) relative to each other when they hit. The crash scattered a huge cloud of "space junk". The space junk is moving at very high speeds. That makes it very dangerous to other spacecraft and astronauts. Several satellite operators are worried about the safety of their vehicles. There is some chance the pieces might hit the Hubble Space Telescope. NASA thinks the International Space Station is pretty safe because it orbits at a lower altitude.
The two spacecraft that collided were an Iridium communications satellite and a Russian Kosmos military satellite. The Kosmos satellite had a mass of 950-kilograms (2,094 lb). It was launched in 1993, but had been out of use and pretty much "dead" since 1995. The Iridium satellite had a mass of 560 kg (1,235 lb). It was launched in 1997 and was still working up until the time of the crash. Iridium's "constellation" of 66 communications satellites includes spares or backups on-orbit. The company is moving one of those to cover the gap created by the destruction of their spacecraft.