ISRO/PTI

LUNAR SURFACE PHOTOGRAPHED by the MIP during its descent.

AT 8.31 p.m. IST on November 14, the Moon Impact Probe (MIP) of Chandrayaan-1, with India’s flag painted on its sides, impacted the moon’s surface and emphatically signalled India reaching the moon. India thus joined Russia, the United States, Japan and the European Space Agency in the elite club of those who have impacted a probe on the lunar surface.

At 8.06.54 p.m., radio frequency engineers beamed commands from the Spacecraft Control Centre (SCC) at ISTRAC, ISRO’s Telemetry, Tracking and Command Network at Peenya in Bangalore, for the MIP to separate from the Chandrayaan-1 spacecraft, two days after it had reached its final orbit of 100 km above the moon.

The MIP separated as planned without any hitch. Soon, its three instruments – a video camera, a radar altimeter and a mass spectrometer – went into action. The video camera took pictures of the moon’s surface during its 25-minute descent; the altimeter measured the MIP’s altitude from the moon; and the spectrometer analysed the constituents of the moon’s extremely thin atmosphere.

The 35-kg MIP, which was built at the Vikram Sarabhai Space Centre in Thiruvananthapuram, followed a curved path and struck the Shackleton crater on the moon’s south polar region exactly as determined, at 8.31 p.m. .

“Just as we had promised, we have given India the moon,” said ISRO Chairman G. Madhavan Nair. “It was during Jawaharlal Nehru’s time that the nucleus for India’s space programme started. It is only fitting that on Children’s Day, celebrated in his honour, India should plant its flag on the lunar surface,” he added.

Former President A.P.J. Abdul Kalam, himself a rocket technologist from ISRO, who was present at the SCC, said: “…Technological excellence and creative leadership at ISRO have combined to make Chandrayaan successful. The whole country should be proud of ISRO.”

M. Annadurai, project director, Chandrayaan-1, called it “ISRO’s gift to the children of India on the occasion of Children’s Day.” S.K. Shivakumar, Director, ISTRAC, was equally happy with the success.

In the entire Chandrayaan-1 mission, every event took place with clock-work precision: the Polar Satellite Launch Vehicle (PSLV-C11) putting Chandrayaan-1 in a perfect, initial orbit around the earth on October 22, the series of manoeuvres to make the spacecraft approach the moon which is about 3,84,000 km away, the critical manoeuvre of inserting Chandrayaan-1 into the lunar orbit on November 8, the manoeuvres to reduce the spacecraft’ s orbit to bring it closer to the moon, the spacecraft reaching its final lunar orbit on November 12, and, finally, the MIP separating from the spacecraft and crash-landing on the moon on November 14.

The sequence of events on November 14 began around 7.15 p.m. The spacecraft got oriented in the right attitude before the command went from the SCC for the MIP to separate from Chandrayaan-1. There were positive signals that the MIP had separated. “For the 25 minutes of its descent towards lunar soil, we received continuous radio frequency signals from the MIP,” Annadurai said. When the signals dropped, it indicated that the MIP had crashed onto the Shackleton crater. Data kept pouring in from the three instruments on the MIP for the entire duration of its descent.

The MIP is a technological forerunner to India soft-landing a rover on the moon in 2012-13. Two other objectives of the MIP mission were to demonstrate India’s capability to impact an instrument at a planned time and at the desired location on the moon and to perform a scientific exploration of the moon at close range.

T.S. Subramanian