Tim Furniss/LONDON

Failure of a Russian/ Ukrainian Zenit 2 booster during launch on 10 September, with the loss of 12 Globalstar mobile communications satellites, may force Boeing to carry a dummy payload rather than a commercial satellite on its first flight of the Sea Launch booster. The launcher is based on the Zenit 2 and equipped with a third stage.

The Boeing-led Sea Launch programme, a $2 billion venture involving partners from Norway, Russia and Ukraine in launching boosters from a converted oil platform, had already been considering launching the first Zenit 3 with a dummy payload rather than risk the Galaxy XI communications satellite. The loss of the Zenit 2 has increased that pressure.

The Galaxy XI rethink - the satellite is owned by PanAmSat - comes in the wake of the loss of the Galaxy X on the failed maiden launch of the Boeing Delta III. The Galaxy IV was also lost in orbit in May. PanAmSat says that it is considering using another commercially proven launcher, such as the Ariane 4, to launch the Galaxy XI.

The Zenit 2 was 272s into its flight when a "-faulty command was issued in the control system, shutting down the engines". The vehicle and its payloads crashed in the Gorno-Altaysk region. The cause has been pinpointed to a Russian computer malfunction.

The Zenit 2 has flown 31 times and suffered eight mishaps, a failure rate of 26%, according to the Airclaims Spacetrack database. The booster, which has lost 19 satellites of the 47 that it has carried, had been booked to fly two more launches involving a total of 24 Globalstars, but these launches have been cancelled.

Globalstar will switch to launch options on Russian Soyuz and Boeing Delta IIs, in addition to flights already manifested for these boosters. The first Soyuz launch of four craft is due on 5 November.

Globalstar will claim $190 million insurance and will have to provide an extra $85 million for the building of replacement spacecraft and new launches. The loss of the satellites brings insurance claims since June to $830 million after in-orbit and launch failures.

Boeing has been buoyed, meanwhile, by the successful launch of a Delta II booster from Vandenberg AFB, California, on 8 September, following the catastrophic loss of the first Delta III on 26 August. Despite that, Boeing is sticking to its plans to launch the next Delta III as planned in February 1999 with the Orion 3 satellite.

The Delta II launch on 8 September placed five Motorola Iridium mobile communications satellites into low earth orbit, bringing the total to 72. The commercial launch of the Iridium system is set for 1 November.

Boeing says a guidance fault caused the Delta III failure, but has not explained what caused the initial roll oscillation that caused the guidance system to react. A guidance fault or aerodynamics are possible causes, the company says.

Source: Flight International