GSLV suffers glitch, fails to deliver geo satellite

BENGALURU: Isro suffered twin setbacks on Thursday as its GSLV-F10 rocket developed an anomaly in the cryogenic upper stage (CUS) and failed to deliver the geo-imaging satellite (Gisat-1) in the intended orbit. The failure of the mission would mean not only the much-anticipated Gisat-1 — officially named earth observation satellite EOS-03 — becoming unavailable, but also raises concerns over the reliability of CUS of GSLV-Mk2.
Isro has been hoping to use this class of rockets frequently for commercial launches. A rocket stacks multiple engines one on top of the other. On Thursday, the third stage, meant to accelerate EOS-03 into orbit, failed to ignite.
The GSLV-F10 took off from the second launchpad of Sriharikota at 5.43am as scheduled and the core stage burnout happened as planned, propelling the rocket on its intended path. The second stage ignition happened some two minutes into the launch and payload fairing (equipment to protect payload) was confirmed by the mission control a little after four minutes of the launch, as planned.
Tense moments followed the second stage shut-off. While the mission control was heard announcing the command for CUS ignition, there was no confirmation about it and telemetry screens began showing a deviation in the path at the third stage.
“Performance of the first and second stages was normal. However, CUS ignition did not happen due to a technical anomaly. The mission couldn’t be accomplished as intended,” Isro said in a statement, minutes after chairman K Sivan announced the same at Sriharikota. “...The third stage should have ignited and performed, and since that did not function properly, we’ve lost the satellite. We are waiting for data to know the exact reason,” he told TOI.
Since the CUS didn’t ignite, the third stage along with the payload didn’t have the required velocity to remain in space. “It impacted on Andaman sea a few minutes later,” a source said. The CUS was at an altitude of 140km when the anomaly occurred.
Isro will set up a failure analysis committee (FAC) to look at the data. Sivan and multiple other scientists TOI spoke with, including Vikram Sarabhai Space Centre director S Somnath, said Isro would need at least 24 hours to elaborate on the anomaly.
This was Isro’s third attempt at launching the satellite. The first was scheduled for March 5, 2020, but was scrubbed minutes before the 26-hour countdown was to begin on March 4, 2020. Isro then planned to launch earlier this year (2021), but it didn’t happen owing to a voltage issue that scientists described as a “minor power problem”.