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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."
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