Senior ISRO scientists at the Vikram Sarabhai Space Centre (VSSC) here have continued their meeting for a second day on Saturday to analyse the reasons for the failure of the PSLV- C39 mission.
The Failure Analysis Committee, headed by VSSC Director K.Sivan, is poring through the flight data of the mission in a bid to understand what went wrong. Dr.Sivan told The Hindu that a simulation exercise would be carried out to zero in on the exact reason. “We are on track and hope to reach a conclusion within a week,” he said.
Payload stuck
The PSLV- C39 mission, carrying the IRNSS-1H navigation satellite, on Thursday failed after the heat shield refused to open and release the satellite. Located in the fourth stage of the rocket, the heat shield, also referred to as payload fairing, protects the satellite from the intense heat generated due to friction with the atmosphere during take off.
The fairing on the PSLV- C39 was programmed to separate from the vehicle three minutes into the flight but the rocket continued to travel with the satellite trapped inside, dragging down the velocity.
Based on the initial inference, informed sources at ISRO said the command for separation had gone through but failed to trigger the mechanical process that pops open the heat shield. They said the investigations were likely to centre on the electrically-initiated pyro devices that initiate the sequence of separation.
Pyro devices use explosive energy generated by charge ignition to sever the components and actuate a release mechanism to push the fairings apart.
What is intriguing for scientists is that the pyro device which probably malfunctioned, is based on an electro-mechanical process, one that is far less complex than thousands of other components in the rocket.
“With all other systems on the rocket working as expected, the C-39 launch itself was successful. The glitch seems to limited to the heat shield separation,” an ISRO engineer who sought anonymity said.
The C39 mission which represented the 41st fight of the PSLV, ISRO’s workhorse launch vehicle, was to launch the IRNSS- 1H navigation satellite as a replacement for the IRNSS-1A which was crippled by the failure of the atomic clocks on board.
