Rain threat to India’s first moon mission
India’s first mission to the moon, Chandrayaan-I is all set for its lunar rendezvous on November 8 as India’s space scientists keep open the option of hoisting it into orbit between October 22 and October 28 from the spaceport here.
There have been 86 manned and unmanned flights to the moon since the then Union of Soviet Socialist Republics launched the world’s first mission on January 2, 1959. This was followed two months later by the US on March 3.
Chandrayaan-I will be the first international study of the Moon. Of the 11 instruments on board, five are Indian, two from the US’s NASA, three from the European Space Agency and one from Bulgaria.
The scientists are not overly nervous about the weather, which has been playing truant with incessant rains over the last three days, during the countdown for the launch at 6.22 am on Wednesday.
A couple of times in the, the Polar Satellite Launch Vehicle (PSLV) has blasted off amid showers. Their anxiety, however, stems from the prospect of lightning and thunderstorm at dawn on Wednesday, which would force them to delay the flight either by a couple of minutes or till early the next morning.
“Rain per se is not an issue, but if there’s lightning or a thunderstorm, we have to delay the lift-off. We will take a call at 5.30 am,” Mylswamy Annadurai, Project Director, Chandrayaan-I, told Hindustan Times.
G Madhavan Nair, Chairman, Indian Space Research Organisation (ISRO), concurred with his colleague: “It has been raining heavily but one must watch for thunderstorms.” Therefore, the launch window would be open through the week—October 22-28. “We have decided that Chandrayaan should keep its date with the Moon on November 8. That will not change. We can push the spacecraft forward during its transfer orbit even if the blast-off is delayed by a couple of days because of thunderstorms. If we delay the flight, we have to advance the launch by four minutes the next morning and likewise (by an additional four minutes) in case of further delays,” Annadurai said.
The 44-metre-tall, 316-tonne PSLV C11, ready to sling the orbiter into space, has been protected from downpours at the second launch pad at the Satish Dhawan Space Centre here. About 18 minutes after the lift-off, the PSLV will jettison Chandrayaan-I into a geostationary transfer orbit, about 23,000 km from the Earth.
From there, the spacecraft would be nudged towards its orbit of 100 km from the Moon (3,86,000 km from the Earth) by firing the motors onboard.