When the Soviet Union launched Sputnik I in 1957, space was a lonely place: The occasional cosmic pebble darted by, and way out there, the Moon circled in silence. Sputnik, of course, has long since fallen to Earth. But another 8,100 man-made objects, mostly space junk, crowd the heavens – in addition to the 773 working satellites that now whirl above the world. And there's more – much more – on the way. During the next decade, space-based communications ventures, including the big systems listed below, will push plenty of new satellites skyward. By 2008, the 1,528 birds pictured – plus another 650 or so – will be keeping watch on the neighborhood.
Future Systems:
GEO: geosynchronous Earth orbit 22,300 miles Main uses: Signal relays for broadcast, cable, and direct TV; meteorology; intelligence operations; mobile maritime telephony. | Inmarsat-3| Spaceway| Astrolink| Cyberstar| Euroskyway| KaStar| Worldspace| Aster| V-Stream| Number of New Birds
| Key Players: | Inmarsat, Lockheed Martin, Matra Marconi Space | Hughes Electronics | Lockheed Martin | Loral, Alcatel, NDS, Adaptec | Finmeccanica, Alenia Aerospazio | KaStar Satellite Communications | WorldSpace, Matra Marconi Space, Alcatel | Spectrum Astro | PanAmSat 74
| Fully operational: | 1998 | 2004 | 2005 | 1999 | 2000 | 2000 | 2000 | 2005 | 2003
| Number of Birds: | 5 | 8 | 9 | 3 | 5 | 4 | 3 | 25 | 12
MEO: middle Earth orbit 1,000-22,300 milesMain uses: Primarily GPS-style surface-navigation systems. MEO will soon host four new constellations of voice and data satellites. | GESN| ICO| Orblink| Ellipso| Number of New Birds
| Key Players: | TRW | ICO Global Communications, Hughes Electronics | Orbital Sciences | Mobile Communications Holdings, Boeing 55
| Fully operational: | 2005 | 2000 | 2002 | 2002
| Number of Birds: | 19 (MEO/GEO) | 12 | 7 | 17
LEO: low Earth orbit 100-1,000 miles Main uses: Because of their proximity to Earth, LEO satellites are useful for communications, spying, and remote sensing. The new breed of low flyers are:little LEOs, mostly for data communications, including email and paging; big LEOs, enabling the worldwide mobile phone network; and broadband LEOs, offering high-speed, high-bandwidth data communications, such as videoconferencing. | ORBCOMM| FAISat| Leo One| LEO SAT Courier| ECCO| Teledesic| Iridium| Globalstar| SkyBridge| Number of New Birds
| Key Players: | Orbital Sciences, Teleglobe, Technology Resources Industries | Final Analysis Communication Services, Lockheed Martin | Leo One USA | Satcon | Constellation Communications | Teledesic, Boeing, Motorola, Matra Marconi Space | Iridium, Motorola | Globalstar, Loral, Qualcomm | Alcatel, Loral 730
| Service: | Little LEO | Little LEO | Little LEO | Big LEO | Big LEO | Broadband LEO | Big LEO | Big LEO | Broadband LEO
| Fully operational: | 1999 | 2003 | 2002 | 2000 | Undetermined | 2003 | 1998 | 1999 | 2002
| Number of Birds: | 36 | 38 | 48 | 72 | 54 | 288 | 66 | 48 | 80
| Present Systems:| LEO| MEO| GEO
| Sixty percent of current satellites, including those in elliptical and other orbits not listed here, are used for communications. The rest? Mostly spy, science, weather, or navigation birds. | 325| 66| 278
Sources: Federal Aviation Administration; Futron; Harvard-Smithsonian Center for Astrophysics
