spacetoday.net: Ariane 5 investigation focuses on main engine

Posted: Fri, Dec 13, 2002, 8:06 AM ET (1306 GMT)
Ariane 5 ESC-A (Arianespace)

The failure of an Ariane 5 launched Wednesday night appears to be caused by a problem with the vehicle's main engine, officials said Thursday. According to a statement issued by Arianespace Thursday, the first anomaly occurred 96 seconds after launch when controllers noticed a small problem with the cooling circuit for the Vulcain 2 engine. Between 178 and 186 seconds a "significant flight control perturbation" took place as the engine speed slowed. The payload fairing was jettisoned as planned at the 187 second mark, but the vehicle then entered an erratic trajectory. With the vehicle off-course and heading for the Atlantic Ocean, controller's triggered the vehicle's self-destruct system about seven and a half minutes into the flight, at an altitude of 69 kilometers. Officials believe the problem is restricted to the Vulcain 2 engine, which is only used on the Ariane 5 ESC-A and not the older version of the Ariane 5. If correct, Arianespace plans to continue with regular Ariane 5 launches as the investigation proceeds, including the launch of ESA's Rosetta comet mission, which much launch between January 13 and 31. An Ariane 4 launch scheduled for December 17 will also take place. An independent commission is scheduled to start its investigation of the failure on Monday. Eutelsat officials said that its payload on the Ariane 5, the 250-million-euro Hot Bird 7 spacecraft, was insured, but CNES's Stentor experimental satellite, worth 388 million euros including launch costs, was not insured, somewhat limiting the exposure of the space insurance industry to this failure.