No Delay Planned for Rosetta Launch
16 Dec 2002
(Source: European Space Agency)
Flight 157 Arianespace
Update from Kourou
The independent inquiry board that will determine the causes of Flight 157's launch failure will begin its work on Monday, December 16.
Arianespace Chief Executive Officer Jean-Yves Le Gall said the board has the task of determining the source of in-flight problems on the first mission of the "10-ton" Ariane 5, and to assess what effect this failure will have on flights of the basic Ariane 5 launcher version.
Speaking to journalists at the Spaceport this morning, Le Gall said Arianespace's next mission - an Ariane 4 launch with the New Skies Satellites' NSS-6 telecommunications spacecraft - remains on schedule for a December 17 liftoff.
In parallel, Arianespace is continuing with preparations for the upcoming Ariane 5 mission, which will use a basic Ariane 5 launcher to place Europe's Rosetta scientific spacecraft on a deep-space trajectory to rendezvous with a comet. This launch has been set for January 12, and Le Gall said activity is continuing on a schedule that would support this target date, pending a go-ahead from the Flight 157 inquiry board.
"The Flight 157 failure has not affected Arianespace's determination to move ahead and to overcome our difficulties," Le Gall told the journalists. "We will not change our overall strategy, and we are confident about the future."
Arianespace is now assessing its planned phase-in schedule for the "10-ton" Ariane 5 launcher version, and will continue as rapidly as possible with the next flights of the basic Ariane 5, he said.
According to Le Gall, Flight 157 encountered problems beginning at approximately 96 sec. into the mission. The anomalies were in the Ariane 5's core stage propulsion system, which is powered by the Vulcain 2 cryogenic main engine. This was followed by flight control difficulties that led to the launcher's controlled destruction over the Atlantic Ocean.
ESA News http://www.esa.int
12 December 2002
Arianespace releases initial information on Flight 157
During a press conference today in Kourou, French Guiana, Arianespace CEO Jean-Yves Le Gall provided initial information on the failure of Flight 157. He also announced the establishment of an independent inquiry board.
Initial data analysis performed last night showed that the countdown, engine ignition and initial phase of flight were normal. A first anomaly occurred 96 seconds into the mission, involving the cooling circuit for the Vulcain 2 engine that powers the main cryogenic stage.
From T + 178 sec to T + 186 sec, the engine speed changed and a significant flight control perturbation occurred. At T + 187 sec, the Ariane 5's payload fairing was jettisoned as planned, but the launcher's attitude was not correct. The launcher subsequently demonstrated erratic behavior.
In compliance with range safety procedures, the launcher was destroyed at approximately 456 sec. into the mission. The Ariane 5 was at an altitude of about 69 kilometers and a distance of 800 kilometers off the coast of French Guiana.
Jean-Yves Le Gall announced that an independent inquiry board is being set up, with members to be named within a few days. The board will have two main objectives:
1. Ensure that the Flight 157 anomaly will not affect upcoming launches of the baseline version of Ariane 5.
2. Analyze, understand and correct the Flight 157 failure causes so that the 10-ton-payload Ariane 5 version can resume launches with high reliability.
The date for the next press conference will be announced shortly following the submittal of initial conclusions by the inquiry board.
The launch date for the next scheduled Arianespace mission, Flight 156, which will use an Ariane 4 to orbit the NSS-6 satellite, has been confirmed for the evening of Tuesday, December 17.
IMAGE CAPTION: [http://www.esa.int/export/esaCP/ESAB9X7708D_index_1.html
] The Ariane 5 ten tonnes on the launch pad at Europe's spaceport in Kourou, French Guiana. This new launcher is able to put a payload of 10 tonnes into geostationary orbit. Credits: ESA/CNES/Arianespace/Photo Service Optique-CSG