Tim Furniss/LONDON

Hughes and the Inmarsat-affiliate company ICO Global Communications, have selected four booster types, to carry 12 mobile communications satellites into orbit from late1998.

The first ICO craft will be on an ILS International Launch Services Atlas 2AS booster. Three more - probably including the ICO 2 and 3 - will be flown on the ILS Proton launcher from Russia.

The McDonnell Douglas Delta 3 has also been allocated five ICO satellites as part of an 11-launch deal negotiated with Hughes. These launches are likely to be used after 1999, as the first Delta 3 will not be flown until late 1998.

Three ICO satellites will be carried on the Boeing-led Sea Launch, which has Ukraine's Zenit booster. Hughes has already signed a ten-launch deal with Sea Launch, of which the ICOs will be part.

Arianespace, which is a notable absentee from the ICO launch manifest, has clearly been a casualty of the failure of the first European Space Agency Ariane 5 in June 1995 and subsequent delays in the programme.

The European launcher company is not expected to receive the new booster until 1998, and also has a full manifest of Ariane 4 launches covering the period of the initial ICO launch schedule.

The 2,750kg, Hughes HS-601 ICO spacecraft are being built as part of a record $2.3 billion deal, which also includes launch services. The ICOs will be placed into intermediate, 10,345km circular orbits in two orbital planes crossing at a 90í angle.

Six satellites have to be in service by 1999 and the system will eventually consist of ten operational satellites and two in-orbit spares.

The spacecraft will provide global telephone, data, facsimile and messaging services through receivers as small as handheld cellular phones. The C-band and S-band transponder-craft will be able to support 4,500 simultaneous telephone calls.

Source: Flight International