CHENNAI: Tension will peak at the Sriharikota spaceport after 1.30pm on Monday, about an hour before the lift-off, when Isro will redo the helium-filling in the cryogenic engine which suffered a glitch that forced an abortion of Chandrayaan-2 on July 15.
Late on Saturday, the space organisation said that the performance of Chandrayaan-2 was normal after rehearsals for the rescheduled launch at 2.43pm on Monday. Isro chairman K Sivan, who reached Sriharikota on Sunday, told reporters at Chennai airport that the mission will be a success, and that the agency expects Chandrayaan-2 to discover several new things on the Moon.
“Corrective measures have been taken … it took us more than a day to do that after the glitch was discovered leading to the cancellation. I can assure you that there will be no such technical snag this time,” Sivan said.
Isro engineers and scientists at the spaceport, however, are spending anxious hours during the run-up, cross-checking that everything is in place. “Whether it is a Moon mission or a Mars mission, whether we are launching a PSLV or a GSLV, the drill is the same. Yes, the tension is more palpable this time,” said a source.
The 20-hour countdown for the July 22 launch started at 6.43pm on Sunday. Filling of propellants will start late on Sunday night and continue on Monday. For all the GSLV-MkIII launches, Isro first fills the solid propellants in the rocket boosters after the countdown begins.
Then it fills the propellants in the core stage (L110), which is a liquid engine using Unsymmetrical dimethylhydrazine and nitrogen tetroxide. Then follows the filling of fuel in the cryogenic stage — liquid hydrogen and liquid oxygen — and then helium.