The failure of the Proton booster on 27 October was caused by "fire in the turbopump of the second stage", says the Russian Aviation and Space Agency.

Engine No 1 on the booster's second stage failed, followed by the shutdown of the other three engines, at 222s into the flight from the Baikonur Cosmodrome. The event is almost identical to an incident on 5 July which caused the failure of another Proton.

Debris from the failed booster, including two engines, has been found 200km (130nm) from Karaganda, but little environmental damage seems to have occurred, unlike in July when fuel and debris were scattered over a large area.

As a result of that accident, Russia is to equip a rapid-reaction emergency team to tackle any launch failures at, or downrange from, the Baikonur Cosmodrome.

The Express A1 communications satellite lost in this most recent Proton failure was insured by Ingosstrakh for $24.4 million.

Proton builder Khrunichev says that, despite the two recent accidents, the launcher has had only three failures in 10 years, during which time 97 missions have been successful, carrying 142 satellites into orbit.

International Launch Services, hit by the previous Proton failure and problems with RL10 upper stage engines on its grounded Atlas fleet, has again put Proton launches on hold.

"The launch business is unforgiving," says new ILS president Mark Albrecht.

Source: Flight International