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Explained: Why ISRO stopped Chandrayaan 2 launch at final moments

Huma Siddiqui

Chandrayaan 2: India’s Chandrayaan-2 space exploration endeavor was to commence in early hours of July 15, from Sriharikota but the countdown clock was put on hold within the last hour (T-56 hour) of launch due to technical snag. This was not the first time that a mission of GSLV has been postponed by the Indian Space Research Organisation (ISRO).

So far there have been a dozen successful missions of the GSLV rockets out of the 16 flown so far. Four were failed missions.

A top officer said on condition of anonymity that “A lot of preparation goes in the launch of any such big mission which is thousand times more complex. And it all could be very well planned; each stage has to be confirmed and cleared and a huge data is taken in to do that.”

Adding, “It was critical for the mission to be re-scheduled as there were issues showing up during sequence checks. The launch needs to be better planned, as the last stages are more critical.”

GSLV MK-III is ISRO’s most powerful rocket, weighing 640 tonnes standing 144m high. The first stage of rocket comprises of two Strap-on boosters, the 2nd stage has two Vikas engines, and 3rd stage has the cryogenic engine. On top of the 3rd stage, the spacecraft component weighs 2,379kg with an Orbiter, Lander and a Rover packed within.

Sharing his views about the re-scheduling of the launch of the Chandrayaan-2 on Monday, Milind Kulshreshtha, Artificial Intelligence and C4I expert, said, “The re-scheduling is a wise decision since a lot is at stake for the nation, then just research and manufacturing expenditure. With automation, the checks on the spacecraft are highly sensitive for the complex space body. The last process of liquid fuel porting into the fuel tank was in progress when the launch was called off for the day.”

According to him, globally, some missions have been either put on hold or re-scheduled due to last minute issues.

The January 28th, 1986 space shuttle Challenger take-off from Cape Canaveral, Florida occurred at just the allowed minimum temperature forecasted -1°C. “However, from thousands of components making the shuttle, O-ring performance at low temperature was the suspected weak link in the chain and two O-rings did give way. These two rubber O-rings were used to seal the joints of the booster to contain the high-pressure gases produced by the burning solid propellant inside and main force of these are aimed towards the nozzle at the aft end of each rocket to attain the huge thrust required to achieve the escape velocity. The investigation attributed the catastrophe to NASA administration’s keenness to not miss the time of launch due Governmental and assumed public pressure,” Kulshreshtha pointed out.

According to him, the SpaceX Falcon 9 rockets keep the propellant at super cold temperatures to shrink its size to increase the quantity in the tanks and make them even more powerful. This advantage comes with a major risk for a manned aircraft since the propellant would need to be loaded just before takeoff, while the astronauts are aboard. A minor accident or a spark at this fuelling exercise could set off an explosion.

With private players like the US-based Boeing and other European private firms too involved, the NASA safety certification becomes critical due to the active competition among these private players with commercial interest.