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The Indian Space Research Organisation (Isro) will get its latest generation satellite Insat-3C into space in early 2002, 16 Januaryy 2002, to be exact, if one goes by a press release from Arianespace, its satellite launch partner.
Insat 3C will be sent into orbit using an Ariane-4 rocket, which may surprise satellite enthusiasts because Isro and Arianespace had initially agreed to an Ariane-5 launch vehicle (flight 143), which had been scheduled for a July blasttoff, but was postponed when a prior flight (Flight 142) ran into trouble.
Flight 142 had a dual satellite payload which did not make it to proper orbit in July, and hence further Ariane-5 missions were aborted until corrections could be made. A committee was appointed to inquire into the mission failure. The enquiry panel had stated that that the malfunction was due to the combustion instability at the ‘EPS‘ upper stage ignition due to the abnormally high pressure gradient in the combustion chamber.
In October (see Launch of Insat-3C not before 2002 - http://www.indiantelevision.com/headlines/y2k1/oct/oct10.htm), Arianespace had said that "the return-to-flight program for the Ariane 5 is moving ahead at present with more than 60 ignition tests of the Aestus upper stage engine having been performed on a test rig in Germany. The data will be used in determining the new ignition sequence. Modifications of the Aestus engine test rig will be made to validate flight conditions during the ground-based static firings." Arianespace CEO Jean-Marie Luton had then said that the next flight of Ariane-5 was targeted for January 2002, following the modifications and the upper stage‘s qualification.
Apparently, things did not pan out with Ariane-5 and with Isro pressing for an early launch, Arianespace decided to use an Ariane-4 rocket, keeping in mind one of its long standing and most dynamic customers, the press release states.
The Arianespace press release adds that: "The recovery plan approved in August is on track towards its goal of resuming Ariane 5 launches in early 2002. All mandatory tests have approved Ariane 5 for launch. Resumption of Ariane 5 is on schedule for late January 2002. The complete recovery plan will increase the fiability and enhance quality of the launcher.
"Ariane 5 is the only new generation launcher which is available, qualified and operational today. It is already adapted to the evolution of the market and to the satellites of the next generation : Ariane 5 ESC-A will reach 10 tons performance mid 2002.
"The Ariane 5 return-to-flight program achieved a major milestone on 10 November when the first Aestus engine ignition test was performed on the modified P4-2 test bench in Lampoldshausen, Germany. Modifications to the Lampoldshausen test bench were undertaken to better simulate the flight conditions during ground tests with the Aestus engine. "The test firing phase clears the way for the continuation of the test program as defined for the action plan‘s next phase. Objectives of the next phase are improvement and qualification of the Aestus engine‘s ignition sequence. "Arianespace conducted the first phase of the next launch campaign (Ariane 511/Flight 145) during late September and early October. The heavy-lift launcher‘s two solid booster stages were mated to the core cryogenic stage, and the vehicle equipment bay was installed atop it. An EPS upper stage was temporarily modified stand and digital models will be used in an attempt to duplicate the conditions which led to the Flight 142 malfunction in July. The P4-2 stand will subsequently be used for acceptance firing tests of the Aestus engines for the upcoming Ariane 5 launchers, as well as for tests to qualify the new ignition sequence."
