Historic voyage to the Moon

T.S. SUBRAMANIAN

IT is a time of reckoning for India’s space scientists as they prepare for the country’s first rendezvous with the earth’s closest neighbour, the moon.

On October 29, the Indian Space Research Organisation’s (ISRO) spacecraft Chandrayaan-1 was on its way to reaching two-thirds of the 3.84-lakh-kilometre distance to the moon. It is expected to enter its final orbit around the moon on November 15.

That morning, three minutes after the firing of its engine system, Chandrayaan-1 was knifing through space in an orbit around the earth with an apogee of 2.67 lakh km and a perigee of 465 km. In this highly elliptical orbit, the spacecraft takes about six days to go round the earth once.

This was the fourth precision manoeuvring of the spacecraft to raise its orbit, but what made the day for the engineers at the Spacecraft Control Centre (SCC) at ISTRAC, ISRO’s Tracking, Telemetry and Command Network at Peenya in Bangalore, was the fact that they started getting signals from Chandrayaan-1.

The previous manoeuvre, on October 26 morning, had Chandrayaan-1 sailing into deep space and reaching almost half the distance to the moon, achieving an apogee of 1.64 lakh km and a perigee of 348 km.

But it was a dreadful launch day on October 22 at the spaceport at Sriharikota in Andhra Pradesh. Tension ran high at the Mission Control Centre as Team ISRO raced against time to complete the countdown for the lift-off of the Polar Satellite Launch Vehicle PSLV-C11 at 6.22 a.m.

“This is the beginning of our long journey to the moon,” declared an exultant G. Madhavan Nair, ISRO Chairman.

“It is a historic moment for India.... We have opened a new chapter [in the history of ISRO’s space exploration programme],” he said, adding: “Everything went perfectly.

It was a remarkable performance by the launch vehicle.... What we have started is a remarkable journey for an Indian spacecraft to go to the moon and try to unravel the mysteries of the moon.... The first leg, and perhaps the most difficult part, has been accomplished successfully.”

Chandrayaan-1, built by the ISRO Satellite Centre (ISAC) in Bangalore, has the most comprehensive set of 11 scientific instruments to fly on board a moon mission.

It will put a total map of the entire surface of the moon in the hands of the scientists in India and abroad.

The spacecraft has a novel combination of remote-sensing and communication capabilities.

Frontline