Tim Furniss/LONDON
The Voronezh Mechanical Engine Plant has been accused of neglect following investigations into two similar Proton launch failures on 5 July and 27 October, with Russian communications satellites.
The review board, set up to establish the cause of the failure on 27 October, says: "The most likely cause of the failure is the presence of metallic or mineral particulate matter inside one of the four second-stage engines, resulting in the ignition of the turbopump's engine assembly. The most likely cause of the particulate matter to finding its way into the engine is poor workmanship at the Voronezh Mechanical Engine Plant."
At T+221.96s, one of the four second stage engines, malfunctioned due to "the unsealing of the engine's exhaust duct followed by the automatic shutdown of the remaining engines". The board pinpointed an "ignition of the turbine exhaust duct", which was similar to burnouts on a 5 July, launch failure and during an engine test on 5 November.
Metallic and non-metallic debris was found in the internal chambers of the second stage, including a piece of asbestos fabric near the valve head of the failed engine. The board concludes that this piece of fabric was located initially in the fuel line downstream of the engine starter valve and must have got into the fuel line during manufacture.
Other non-metallic and metallic debris, plus sand particles, were also found. Several examples of neglect in manufacturing engine components at Voronezh "have been found", the review board says.
Meanwhile, ILS International Launch Services predicts a return to flight of the Proton booster as early as next month, carrying the Garuda 1 commercial satellite. This schedule may be optimistic, however, as all second-stage engines on Protons already assembled are likely to require replacement.
Source: Flight International
