Steve Nichols and Tim Furniss

Aeronautical equipment for the new Iridium satellite telephone service is making its debut on the AlliedSignal stand (Hall 4, Stand F8).

Promising to deliver telephone calls from every part of the planet, on the ground or in the sky, the Iridium service is due to be launched commercially on 23 September, despite many setbacks.

Iridium uses a "constellation" of low-earth orbiting satellites. When you use a phone it connects to whichever satellite is currently overhead, transferring you to the next one in the chain before it disappears over the horizon.

The satellites are at a height of only 485 miles (780km), much lower than their geostationary cousins 35,000km away.

Their low altitude means a conventional-looking cellphone can be used without a dish, but the main advantage is that the phone will work anywhere on the planet.

But there have been problems.


Bill Peltola, Iridium's regional director, says: "It's difficult to keep a network of 66 satellites working all the time, so we do have spares.

"We've launched more satellites from China recently and had another on a Delta II booster launched from Vandenberg Air Force in the US on Tuesday."

The Boeing launch follows the catastrophic loss of the company's first Delta III on 26 August. This latest launch placed five Motorola Iridium satellites into orbit.

These, based on spacecraft buses from Lockheed Martin, replace five satellites that have experienced anomalies in orbit.

Seventy-nine satellites have now been launched on 17 boosters, giving 72 operational satellites - 66 working systems and six spares. A further two non-operational Iridiums still need replacing.

Desmond O'Brien, AlliedSignal's Air Transport Manager, explains: "AlliedSignal is providing Iridium phone systems for aircraft. The range includes one, five and eight channel systems.

Source: Flight Daily News