HELSINKI — India’s bid to become the fourth country to land on the moon ended with loss of contact with the Chandrayaan-2 mission lander during the final stages of the Sept. 6 landing attempt.
The Vikram lander began a powered descent just after 4 p.m. Eastern Friday, 46 days after launch, targeting a high plain 70.9 degrees south of the equator, some 550 kilometers from the south pole.
A live stream from the Indian Space Research Organisation (ISRO) showed the lander making its descent as planned from its previous 36 by 110-kilometer orbit down to a fine braking phase below six kilometers.
However footage illustrating the spacecraft’s descent trajectory stopped just short of reaching surface. After minutes of silence, ISRO chairman K Sivan announced that communications with the lander had been lost.
“Vikram lander descent was as planned and nominal performance was observed up to an altitude of 2.1 kilometers. Subsequently the communications from the lander to ground stations was lost. The data is being analyzed,” Sivan said.
No further information was immediately available and the fate of the lander remains uncertain.
Indian Prime Minister Narendra Modi, who was present at Indian Space Research Organisation (ISRO) mission operation complex at Bengaluru, told press following the communications loss that, “it is not a small thing that we have achieved. Be courageous.”
The landing attempt continues a surge of lunar-related activity in 2019, following a failed soft landing attempt by an Israeli spacecraft in April and China’s unprecedented January lunar far side landing. The United States in March announced plans to accelerate a human lunar program with the target of a first landing in 2024.
Minutes of terror
India was aiming to join the United States, the Soviet Union and China as the only nations to have soft-landed on the moon.
The $150 million mission involved a circuitous, 46-day journey to the surface of the moon. Launch July 22 was followed by a series of orbit-changing maneuvers carried out both ahead of trans-lunar injection and following lunar orbit insertion.
Following separation from the Chandrayaan-2 orbiter Monday the Vikram lander began imaging the primary site, between craters Manzinus C and Simpelius N, and secondary target in preparation for landing.
ISRO chairman K Sivan told Indian media in the run-up to the event the “very complex process” of final approach and autonomous landing would be “15 minutes of terror”. A similar phrase has been used by NASA to describe entry, descent and landing phases of Mars missions.
Vikram and Pragyan
Aboard the 1,471-kilogram lander was a 27-kilogram rover named Pragyan, meaning ‘wisdom’ in Sanskrit, which was scheduled to be deployed onto the lunar surface about four hours after touchdown.
Chandrayaan-2 is a three-part mission which consisted of an orbiter, lander and rover. The orbiter is in a 100 by 100-kilometer lunar polar orbit where it is expected to operate for one year. Its eight payloads include a Terrain Mapping Camera, which will produce a 3D map for studying lunar mineralogy and geology. It also carries an X-ray spectrometer, solar X-ray monitor, imaging spectrometer and a high-resolution camera.
Both Vikram and the Pragyan rover had a design lifetime of one lunar daytime, equivalent to around 14 Earth days. While ISRO will attempt to reactivate the spacecraft following the end of the lunar night, the spacecraft have not been equipped to survive expected temperatures of about minus 180 degrees Celsius (minus 292 Fahrenheit).
The lander was equipped with a seismometer and a laser retroreflector, while the rover carried an alpha particle X-ray spectrometer and laser induced breakdown spectroscope. These payloads, together with those on the orbiter, mean there is good science potential, Clive Neal, a lunar scientist at the University of Notre Dame, told SpaceNews ahead of the landing.
“The geochemical instruments on the rover will give us an indication of the materials around the landing site and give another point of ground truth for calibrating the orbital detests we currently have and those that will be collected in the future,” Neal noted.
Asian space competition
Rajeswari Pillai Rajagopalan, head of the Nuclear and Space Policy Initiative at the Observer Research Foundation in New Delhi, India, told SpaceNews ahead of the landing attempt that the Chandrayaan-2 mission is a sign of India maturing as a space power.
The mission is also significant in terms of larger geopolitical and space competition within Asia, Rajagopalan notes. India and Japan are now looking to deepen collaboration in lunar exploration at a time rival China is preparing robotic lunar sample return and polar landing missions.
Rajagopalan expressed the hope that the publicity surrounding the Chandrayaan-2 mission will help lead to public debate on and development of an Indian national space policy, covering India’s disparate space activities and capabilities.