ISRO expects it will perform smoothly this time; earlier one failed in April 2010
As Geo-synchronous Satellite Launch Vehicle (GSLV-D5) is slated to lift off around 5 p.m. on August 19 from Sriharikota, and various checks showing that the vehicle is in the pink of its health, the mood is one of optimism at the spaceport.
The mission’s significance is that GSLV-D5 is powered by an indigenous cryogenic engine and Indian Space Research Organisation (ISRO) has used every expertise available in the country to ensure that the engine performs smoothly this time. The rocket will put India’s advanced communication satellite called GSAT-14, weighing 1,980 kg, into orbit.
ISRO Chairman K. Radhakrishnan told The Hindu, “The Mission Readiness Review (MRR) has cleared the vehicle. The integration of the satellite with the launch vehicle has been completed. On August 11, we plan to move the vehicle to the launch pad.”
There is enormous focus on this mission, as the GSLV flight with an indigenous cryogenic engine failed in April 2010. The subsequent GSLV flight with a Russian cryogenic stage also failed in December of that year.
S. Ramakrishnan, Director of Vikram Sarabhai Space Centre (VSSC) in Thiruvananthapuram, brimmed with confidence when asked whether the indigenous cryogenic engine would perform well this time.
“Of course,” he said. “We are doing well. We have done all the possible tests. As of now, the [cryogenic] stage health is fine. All checks show that the health of the vehicle is all right.”
It would take about an hour for the 49-metre tall rocket, weighing 414 tonnes, to roll on a one-km long rail track from the 17-storey tall VAB (Vehicle Assembly Building) to the launch pad on August 11. A platform with wheels, on which the three-stage vehicle was stacked up inside the VAB, would ferry the rocket to the launch pad.
Mr. Ramakrishnan said, “Once we go to the launch pad, we will connect the umbilicals. During the final countdown, which will be of the order of 35 hours, the rocket will be filled with propellants. The satellite has already been filled with propellants.”
M.C. Dathan, Director of the Liquid Propulsion Systems Centre (LPSC), called the August 6 MRR “a wonderful meeting,” because “there was no apprehension or anxiety” excepting a couple of minor issues. Tests on the vehicle yielded positive results.
Mr. Dathan asserted “we have made use of every possible expertise available in the country” to ensure that the indigenous cryogenic engine performed flawlessly. This included expertise from the academic institutions, and research and development centres.
In April 2010, the indigenous cryogenic engine ignited; the steering engine and the gas generator ignited, but the ignition could not be sustained beyond 800 milliseconds and the fuel booster turbo pump (FBTP) stopped.
Dr. Radhakrishnan elaborated on the steps taken to address the inadequacies of the 2010 flight. He said, “Over the last three years… we have done a series of ground tests on the sub-systems and the cryogenic engine” at the LPSC at Mahendragiri, Tamil Nadu, “after making the necessary design changes in the FBTP and the oxidiser turbo pump.” An important test done this year was testing the FBTP in operating conditions at cryogenic temperatures. Ignition of the engine in high-altitude conditions [simulating the vacuum in space] was also done. The duration of this test was 3.5 seconds, when the ignition of the main engine, the gas generator and the two steering engines should take place in a given sequence. “This happened.”