Globalstar is a consortium of international telecommunications companies formed in 1991 to provide a worldwide satellite-based telephony service. Together with Iridium, ICO, and others, Globalstar is one of the new comsat companies supporting global mobile voice and data communications with a constellation of satellites in low Earth orbit. The Globalstar constellation, launched in 1998-99, consists of 48 satellites (with four in-orbit spares) in 1,400-kilometer-high orbits inclined at 52°, allowing a concentration of coverage over the temperate regions of Earth from 70° S to 70° N. The satellites operate in the L-band (see frequency bands). Space Systems Loral is the prime contractor for the constellation; in parts of the globe lacking a communications infrastructure, the handheld Globalstar unit, supplied by Qualcomm, sends a signal to a satellite overhead. The satellite then relays this signal to a regional ground station where the signal travels through a terrestrial network to its final destination.