India touches the Moon

The 35-kg Moon Impact Probe (MIP), one of the 11 payloads on Chandrayaan-I, ejected from the main spacecraft — orbiting around the moon at a distance of 100 km — at the appointed time of 8.06 pm. And, after a 25-minute textbook journey, hit the lunar surface at a designated location on the Shackleton crater near the moon’s south pole.

The MIP became the first Indian object to leave its imprint on the moon’s surface. The United States, the erstwhile USSR and the European Space Agency are the only other three to have “deliberately landed an object on the moon.”

“As promised, we have given the moon to India,” said a beaming ISRO chairman G Madhavan Nair, the face to this historic achievement scripted by a team of hundreds of scientists of all disciplines working 24 by 7 for close to four years at a cost of Rs 386 crore, the least expensive mission to the moon so far.

“It has a huge symbolic value apart from being a tremendous scientific achievement,” said Mylswamy Annadurai, mission director of Chandrayaan-I. “We are literally over the moon,” he told The Indian Express. “But there is still a lot of science left in Chandrayaan. The real scientific experiments start now.”

The spacecraft, which is now left with 10 payloads, will continue in its present circular orbit for the next two years and carry out a variety of scientific experiments. These include testing the possibility of presence of water on the moon’s surface, mineral mapping of the lunar terrain and details about the presence of Helium-3.

If the sense of joy at ISRO’s Telemetry Tracking and Command Centre was overwhelming, so was the tension as the clock pushed past 8 pm. Giant screens across the room streamed in various health parameters for the probe — including temperatures and data transfer rate.

Former President A P J Abdul Kalam, who had proposed the idea of landing a probe on the moon when ISRO had been hesitant, was present, next to Nair.

At 8.06 pm, the command centre transmitted orders to the spacecraft to initiate the process of separating the probe. Within 10 minutes, smiles began appearing around the room as the first signs came in of the MIP being on course to putting the Indian flag on the moon’s surface.

At the end of 25 minutes — described by the ISRO chairman as being “precise to the second” — when the probe touched down on the moon at a speed of 1.6 km per second, a wave of triumph and relief swept across the centre. “We knew things were going smoothly at 8.4 seconds after the probe separation command was given because the health status of the probe began appearing and every thing seemed to be going fine,” said Annadurai. The first hurdle was crossed when the probe snapped the cable acting as an umbilical cord to the spacecraft and began spinning down to a predetermined spot over the Malapert Mountain and onto the crater at the moon’s south pole.

“The snap was a key moment in the mission when the probe traveled on its own with its three instruments, including a video camera switched on and transmitting data via radio frequency back to the satellite,” Annadurai said.

Within minutes of the “snap,” data recorders aboard the spacecraft were flooded with information from the probe. This data will be received at ISRO’s Deep Space Network when the spacecraft is on a visible side of the moon in the early hours of November 15, ISRO officials said.

The probe, during its short life span of 25 minutes, carried on board equipment to analyse data crucial for future lunar “lander and rover” missions planned for Chandrayaan-2, slated for launch in 2011-12. For this, the MIP had a C-band altimeter which calculated the real-time height of the MIP during its descent, a video imaging system that provided close-up pictures of the moon as it came closer and closer to the surface, and a mass spectrometer for measuring the constituents of the lunar atmosphere.

Of these, the altimeter and the video-imaging system will be part of a future lander mission as well. The altimeter’s real-time data is crucial for the success of the lander. Unlike the MIP, a future landing mission won’t land at a designated location but will be able to guide its way to an appropriate site.

Key to this is data from the MIP’s video-imaging system. If the terrain is not hospitable, the lander will manoeuvre its way to a more “suitable” destination. Initial reports from ISRO said both these instruments on the MIP worked perfectly well and relayed data as expected.

A GIANT LEAP, A FIRST STEP

The MIP (above) is a bit of India on the Moon. Only the US, erstwhile USSR and the European Space Agency have landed objects on the moon before India. “It’s a tremendous scientific achievement, with huge symbolic value,” said mission director M Annadurai.

But the real experiments start now. MIP’s primary objective was to demonstrate technologies for future lander and rover missions on Chandrayaan-2, slated for 2011-12. Initial reports said all instruments on board worked perfectly.

Chandrayaan will now orbit the Moon for the next two years, carrying out a variety of scientific experiments.