US, Russian satellites collide

12.02.2009
A commercial Iridium communications satellite and decommissioned Russian satellite both appear to have been destroyed after an unprecedented collision in space, Iridium said Wednesday.

The collision took place on Tuesday and was verified by U.S. government organizations that track satellites and other orbits, said Iridium, which is based in Bethesda, Maryland.

The Iridium network, which offers satellite telephone and data service to governments, corporations, media and other groups worldwide, is made up of 66 satellites orbiting approximately 800 kilometers above the Earth's surface. This low-earth orbit means the satellites orbit the globe continuously and so, if enough are put into space, all parts of the planet can be covered with service at all times.

In contrast, typical communication satellites like those used for TV broadcasting orbit at 36,000 kilometers so they appear at the same spot in the sky when viewed from earth. This means reception systems can be simple because dish antennas don't have to move, but such satellites have trouble covering higher northern and lower southern parts of the globe.

The in-orbit collision will mean brief service outages for some customers over the next few day,s but Iridium said it expects to have the issue largely resolved by Friday. Within a month, the company expects to have one of a number of in-orbit spare satellites moved into position to replace the one that was lost.