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http://timesofindia.indiatimes.com/...ld-glitch-isro-chief/articleshow/60343839.cms
NEW DELHI: ISRO Chairman AS Kiran Kumar on Saturday firmly denied that the PSLV-C39 rocket carrying eighth navigation satellite IRNSS-1H failed on Thursday as it was carrying one-tonne extra load.
A report in TOI on Saturday had stated that "the PSLV C-39 rocket, which failed to launch the IRNSS-IH, was dragged down by at least one tonne extra weight''. The report stated that this was more than the design permitted.
Speaking to TOI on Saturday prior to making a presentation at the Nehru Centre in Mumbai, the ISRO chief said: "The report is incorrect and the rocket was not carrying any extra load." He said the heat shield added additional weight to the launch vehicle as it failed to get detached at the second stage and went along till the fourth stage separation point. "It was not because ISRO put any additional weight prior to the launch,'' he said.
He added that a portion of the rocket with the satellite enclosed in the heat shield was currently orbiting 163km x 6,600 km and was being tracked by the multi-object tracking radar at Satish Dhawan Space Centre, Sriharikota. "It is expected to remain this way for another 25 days,'' he said. Kiran Kumar said a failure analysis committee was being formed to study the setback.
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.
Dr K Sivan, director of Vikram Sarabhai Space Centre (VSSC), said, "Launch failure will not affect future missions as they will go as planned. But corrective measures will be taken in future for all types of vehicles as the heat shield separation mechanism is similar in all launchers."
The unsuccessful launch has necessitated the urgent launch of the ninth navigation satellite IRNSS-1I. Dr Sivan said the "standby ninth satellite will be launched soon".
NEW DELHI: ISRO Chairman AS Kiran Kumar on Saturday firmly denied that the PSLV-C39 rocket carrying eighth navigation satellite IRNSS-1H failed on Thursday as it was carrying one-tonne extra load.
A report in TOI on Saturday had stated that "the PSLV C-39 rocket, which failed to launch the IRNSS-IH, was dragged down by at least one tonne extra weight''. The report stated that this was more than the design permitted.
Speaking to TOI on Saturday prior to making a presentation at the Nehru Centre in Mumbai, the ISRO chief said: "The report is incorrect and the rocket was not carrying any extra load." He said the heat shield added additional weight to the launch vehicle as it failed to get detached at the second stage and went along till the fourth stage separation point. "It was not because ISRO put any additional weight prior to the launch,'' he said.
He added that a portion of the rocket with the satellite enclosed in the heat shield was currently orbiting 163km x 6,600 km and was being tracked by the multi-object tracking radar at Satish Dhawan Space Centre, Sriharikota. "It is expected to remain this way for another 25 days,'' he said. Kiran Kumar said a failure analysis committee was being formed to study the setback.
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.
Dr K Sivan, director of Vikram Sarabhai Space Centre (VSSC), said, "Launch failure will not affect future missions as they will go as planned. But corrective measures will be taken in future for all types of vehicles as the heat shield separation mechanism is similar in all launchers."
The unsuccessful launch has necessitated the urgent launch of the ninth navigation satellite IRNSS-1I. Dr Sivan said the "standby ninth satellite will be launched soon".
