Tim Furniss/LONDON

US/RUSSIAN SATELLITE-launcher company International Launch Services (ILS) is planning to introduce a Proton M model in 1997, capable of carrying two Hughes HS-601-class satellites into geostationary orbit (GEO). The launcher will compete head-on with Arianespace's Ariane 5.

ILS, which markets the US Atlas and Russian Proton launchers, has contracted Matra Marconi Space (MMS) to develop the dual-satellite container for the vehicle.

The Proton M will be able to place 4,500kg directly into GEO, using its restartable KVD-1 cryogenic fourth stage. The current Proton GEO capability is 2,600kg.

This is reduced to about 2,100kg by the design characteristics of Western communications-satellite payloads, such as the HS-601, which require different launch parameters, particularly a later payload-fairing jettisoning.

The Ariane 5 will offer a 6,800kg capability to geostationary transfer orbit (GTO), the equivalent of two HS-601 class spacecraft. Satellites in GTO use their own engines to reach circular GEO. An HS-601 consumes about 1,175kg of propellant en route from GTO to GEO, so it weighs about 1,800kg at its final destination.

The Ariane 5, which is scheduled to have two demonstration flights for the European Space Agency (ESA) in 1996 before being operated commercially by Arianespace, was to have been the only booster offering dual-satellite launches after its predecessor, the Ariane 4, has been phased out.

MMS, which manufactures the Spelda dual-satellite launch system for the Ariane 4, is in the preliminary design phase for a dual-satellite carrier for the Proton. ILS partners Lockheed Martin and Russia's Khrunichev and Energia have authorised final design and development.

The Proton M dual-satellite carrier will be based on the technology used in the Spelda, built originally by the former British Aerospace Space Systems, now part of MMS.

BAe had lost out on the Ariane 5 dual-satellite carrier contract when the UK Government did not commit funds to the Ariane 5. The Ariane 5's dual-satellite system called the Speltra, is now being built by Daimler-Benz Aerospace.

A flight-control test on the development and qualification version of the cryogenic main stage of the Ariane 5 launcher at Kourou, French Guiana, was aborted this month when a high-pressure oil line burst. ESA says that the impact on the Ariane schedule, aiming for a maiden flight in January 1996, "...is being studied and information will be forthcoming". It is believed that the maiden flight is likely now to be delayed until March 1996.

Source: Flight International