The Iridium satellites are to fly in orbits 483 miles high.

The Khrunichev plant signed a $156 million contract to launch 21 Iridium satellites on three Proton-K rockets in 1997-1998.

Most of the floats use the Argos System of satellites to recover data, though a few are using the newer Iridium satellite constellation.

The Iridium satellite, which was operational at the time of the collision, was destroyed, as was Kosmos-2251.

At one stage there was a threat that the Iridium satellites would have to be de-orbited; however, they remained in orbit and operational.

Some types of buoys, such as those used for the tsunami warning system, use Iridium satellites to communicate with their base.

Iridium satellites are to be launched starting in 2015.

The ninety eight Iridium satellites used the LM-700A configuration, specialised for communications.

Alternatively, one may use the commercial Iridium satellites which allow higher data rates.

Since Iridium satellites will have to be replaced frequently, the success rate for launchings will be of great concern.