The Hindu : Front Page : Indigenous effort all the way
Indigenous effort all the way
T.S. Subramanian
Another picture of the moon taken by the Moon Impact Probe on Friday.
CHENNAI: What was extraordinary about the historic event of Chandrayaan-1’s probe landing on the moon on Friday night was that the spacecraft was built in India, it was put into orbit by the Indian rocket, PSLV-C11, and the launch took place from Indian soil, said a jubilant M. Annadurai, Project Director, Chandrayaan-1. Mr. Annadurai led the team that integrated the 11 scientific instruments, including the Moon Impact Probe (MIP) into the Chandrayaan-1 bus at the ISRO Satelllite Centre, Bangalore. The MIP was built by the Vikram Sarabhai Space Centre (VSSC), Thiruvananthapuram.
“We have got all the data. We are working on the data and processing them,” Mr. Annadurai said.
S. Ramakrishnan, Director (Projects), VSSC, called it “a momentous occasion for ISRO and India because it is for the first time that we have sent a spacecraft to an extra-terrestrial body and its MIP with the logo of the Indian flag has reached the moon soil.”
Everything went as per schedule right from the separation of the MIP at 8.06.54 p.m. IST from Chandrayaan-1 to the MIP impacting on the Shackleton crater 25 minutes later, Mr. Annadurai said. The entire sequence of events began at 7.15 p.m. at the Spacecraft Control Centre (SCC), which was the nerve-centre of the operations, at the ISRO Telemetry, Tracking and Command Network (ISTRAC), Bangalore, headed by its Director S.K. Shivakumar.
The spacecraft got oriented in the right attitude before the command went from the SCC for the MIP to separate. The MIP separated as per plan and “we got the positive signal that it had separated,” Mr. Annadurai said. Then the data link from the cable to the radio frequency got changed as per plan. “For 25 minutes of its descent towards the lunar soil, we received continuous radio frequency signal from the MIP,” he added. About 300 seconds after the separation of the MIP, the SCC received signals of a reduction in the velocity of the descent of the MIP indicating that the retro-rocket had fired.
Twenty-five minutes after the separation began,
“the receiver went on unlock, indicating that the MIP had impacted on the Shackleton crater on the moon,” said Mr. Annadurai. “The trajectory of the MIP was excellent,” he said.
As the MIP crashed on the lunar surface, it self-destructed.
Earlier, data from the video-camera of the MIP, its radar altimeter and mass spectrometer kept pouring in simultaneously throughout the 25 minutes of the MIP’s descent. The video-camera had taken a number of pictures of the moon’s surface.
As this sequence was being enacted, Chandrayaan-1, the mother-spacecraft, had gone behind the moon.
“We have had a good success and everything went as per our aim. What is important is that the former President, A.P.J. Abdul Kalam (a rocket technologist himself) was present at the SCC during the occasion,” said Mr. Annadurai.
Mr. Ramakrishnan called it “a precision mission” in which the MIP was in communication with the mother-spacecraft during all the 25 minutes. The MIP separation was indicated by a disturbance in the Chandrayaan-1. Its gyros and sensors sensed the separation. “We could see the spin-up and de-orbit motors work [on the plot-board],” he said.
“Everything went precisely in this mission. Right from the PSLV-C11 launch on October 22, the Chandrayaan-1 being safely inserted into the lunar orbit on November 8, the MIP separating from Chandrayaan-1 and its impacting on the moon, everything performed with clock-work precision,” Mr. Ramakrishnan said.