OVER the next five years there will be new galaxies of satellites orbiting the earth like electronic necklaces. More numerous, cheaper and closer to earth than traditional communications satellites they will make mobile phones truly mobile. A hand held phone will be usable almost anywhere on earth for a relatively modest fee - ($3 per minute has been mentioned). Where phones go, computers follow quickly, so there will be worldwide connectivity to the Internet, plus paging and datacast services.
Last week Boeing won the contract to build and deploy the $9 billion satellite network planned by Teledesic. This US privately held company is owned mostly by Bill Gates of Microsoft and Craig McCaw, a fellow billionaire who made his money by being one of the first into US cellular phone networks. Boeing is also to invest $100 million in Teledesic, taking a 10 per cent stake.
Over 18 months beginning in 2001, Teledesic plans to launch 288 satellites, which will orbit the earth in 12 separate 24 satellite chains. From about 800 miles up, these low earth orbiting satellites (LEOS) will rain down, voice, data and video links at speeds comparable to fibreoptic landlines, Teledesic says.
The Teledesic contract is a major victory for Boeing, which wants to rapidly grow its defence and space business. Its partly owned subsidiary, Sea Launch, is building a mobile, ocean based satellite launch platform, and the aerospace giant is expanding its space business aggressively through the recently completed acquisition of Rockwell International units and a planned purchase of McDonnell Douglas.
Teledesic and Boeing will not have the skies to themselves. Among their potential competitors are the Iridium, ICO and GlobalStar consortia, plus Odyssey, Constellation and Ellipso.
Iridium, which includes Motorola among its backers, plans a network of 66 satellites. It will be the first to launch, and would have had satellites in orbit since January but for launch problems. Iridium is due to go live next year, providing voice, fax, paging and data communications from handheld devices. Data rates on Iridium will be only 9,600 bits per second (compared with Teledesic's two megabits) but the appeal will be directly to individuals, with their own phones and pagers, rather than to companies.
For its part, Teledesic's chief executive David Twyver says: "We expect our customers to be companies rather than individuals, initially at least. Almost every company now is putting mission critical internal applications on Internet style back bones, and they'll need to get access to every one of their sites."
Individually, each of these competing satellite projects is huge, with multi million pound budgets and dozens of suppliers. One Irish company with a particularly large input is Iona Technologies, whose Orbix software will be used to control the switching of calls between Iridium satellites and earth stations.
Communications satellites are not new, of course - but their size, cost and high altitude have made them expensive and limited them to specialised uses.
Traditional satellites weigh tons and need enormous launch rockets. They circle the earth at altitudes of up to 22,000 miles, sitting over the equator and orbiting at the same speed as the earth's rotation. This makes them "geostationary" they appear to be hovering over the same spot on earth.
At these altitudes as few as three satellites can "see" the entire surface of the earth. But the heavy satellites have meant huge launch costs, with correspondingly high usage costs, while the high altitudes mean that the earth terminals have to be powerful - and bulky. (The neatest terminals for the existing Inmarsat satellites are about the size of a hefty briefcase.)
LEOS satellites get away from the geostationary principle. They will orbit over the poles while the earth rotates beneath them, giving each satellite a "footprint" that roves over the surface of the planet. There will be so many in a constellation, however, that all the earth will be covered at a given time. A satellite to which a user "uplinks" may not have an earth station within range to patch the call back into the terrestrial phone system. In this case the connection will be banded off to other satellite(s) until it can get back to earth.
Overall, the effect is of a high tech version of the cellular phone system based in space, with each satellite creating a single cell. Come to think of it, it's not so long since cellular phones were the latest thing in staying connected...