The last few moments before India’s sojourn to the Moon
Chandrayaan-1, the first Indian Mission to Moon was launched on October 22, 2008 by PSLV-C11 from Satish Dhawan Space Centre.
The satellite made more than 3400 orbits around the Moon before the mission was concluded when the communication with the spacecraft was lost on 29 August 2009.
With the launch of this mission, India joined the elite group of countries who have performed lunar missions by launching unmanned missions to the Moon.
Prior to the launch, the transfer of data from lunar orbit through Indian Deep Space Network(DSN) and Indian Space Science Data Centre (ISSDC) was developed.
On 14 Nov 2008, the Moon impact probe separated from the Chandrayaan orbiter and struck the lunar surface.
As we celebrate 9-years of the successful conclusion of this mission, Srinivasa Hegde, Mission Director at TeamIndus, writes on the final moments of the Chandrayaan-1, of which he was Mission Director.
After a successful lunar orbit capture nine years ago on Nov 8, ISRO’s Chandrayaan-1 was in the lunar orbit of 500 km x 7500 km. All the burn signatures were nominal and we were waiting for first confirmations of the event through telemetry and Doppler data.
The first signatures came in terms of the multi-layer insulation’s outer layer temperature showing a spike, indicating proximity to the Moon followed by the expected trend in Doppler data.
We had some setback on November 9 as a DC/DC converter failed. We quickly activated redundancy and carried out the requisite re-configurations to proceed with the mission. Further lunar maneuvers were carried out on successive days establishing a circular orbit of 100 km around the Moon on Nov 12.
On Nov 14, two rehearsals were carried out with Moon Impact profile’s(MIP) deployment attitude.
At -14:36 UT, MIP was released from Chandrayaan-1, which was autonomous from the release. We had a 500 kbps radio frequency link.
The small solid motors spun the MIP and another solid motor gave the required deboost velocity.
Through out the 25-minute long descent, we got the data captured by the MIP camera on Chandrayaan's solid state recorder.
The spacecraft recorded all this data in its on-board memory for later readout.
Finally, the probe had a hard landing on the lunar surface that terminated its functioning. The impact was confirmed by Automatic Gain Control(AGC) of the radio-frequency link and downlink breakout.
On November 15, the parabolic Dual Gimbal antenna(DGA) was deployed and the recorded MIP data was played back. It was a proud moment for all of us to see the Mission becoming a successful one over the next few weeks.
India’s first inter-planetary probe has survived the vagaries of space and was recently spotted by NASA using their new ground-based radar technique.
I am often asked why a country like India should mount a Moon mission. I have thought deeply about it and one of the reasons that I feel strongly about is that many a time countries who have access to resources, tend to form a club and keep everyone else away from it. Moon is a fantastic source for many valuable resources including Helium 3, which can take care of the energy needs of all mankind.
The new space race promises big returns for investments in space exploration, evident by the moon rush kick started by the private space companies. Moon mining for the 3 crucial elements: Water, Helium-3, and Rare Earth Metals has captured the attention of the entire space industry, inspiring commercial ventures. Being space infrastructure ready is critical to become a part of the elite club of countries that are future ready.
We have to be there, not just because we humans are explorers, but also because it can help India and humankind lead a more sustainable life. And that is just one reason.
This is a special series where our scientists and engineers share their take on the major space events across the world. This article is by TeamIndus Mission Director Srinivasa Hegde Naravi.