India’s third mission to the moon – Chandrayaan 3 –was successfully launched by its biggest rocket, the Launch Vehicle Mark-III (LVM3), from the Satish Dhawan Space Centre in Sriharikota at 2.35 pm on Friday, July 14. This is the second such mission by the Indian Space Research Organisation (ISRO) to soft-land near the lunar south pole after Chandrayaan-2 failed to do so in its final moments in 2019. If the mission is successful, India will be the first in the world to soft-land near the moon’s south pole and the fourth country ever after the former USSR, the United States, and China to land a spacecraft on the lunar surface.
Just over 16 minutes into its flight or at about 2.50 p.m., the rocket successfully ejected the Chandrayaan-3 spacecraft at an altitude of about 179 km. Chandrayaan-3 will now begin its long journey to the moon, traveling a distance of 3.84 lakh km. Chandrayaan-3 is expected to make a soft landing on the moon on August 23 or 24.
Speaking after the successful launch, S Mohana Kumar, Mission Director said, “LVM-3 has injected Chandrayaan 3 satellite into the precise orbit. Once again, the vehicle has proved to be the most reliable heavy lift vehicle of the Indian Space Research Organisation.” Thanking the extended ISRO family, he went on to say, “This is the penance of so many across the ISRO centres for the past 73 days.”
P Veeramuthavel, Project Director said all the health parameters of the spacecraft are normal. “The journey to the moon has begun now for the most-awaited soft-landing. We will be closely monitoring the spacecraft from Bengaluru. Many critical maneuvers are lined up,” he said.
Union Minister of State for Science and Technology Jitendra Singh, who was present during the launch said, “It is indeed a moment of glory for India and a moment of destiny for all of us in Sriharikota, who are part of history in making. Thank you team ISRO for making India proud.”
Friday was the fourth operational mission of the LVM3, which was earlier known as the GSLV (Geosynchronous Satellite Launch Vehicle) Mark-III. While the first rocket’s first stage is powered by solid fuel, the second stage is by liquid fuel, and the third and final stage consists of a cryogenic engine powered by liquid hydrogen and liquid oxygen. At the time of blast off, the 642-ton rocket had a total propellant mass of 553.4 tons - all three stages put together.
The Chandrayaan-3 spacecraft comprises a propulsion module (weighing 2,148 kg), a lander (1,723.89 kg), and a rover (26 kg), the ISRO said. Incidentally, the Chandrayaan-2 payload weighed about 3.8 tons with the orbiter weighing 2,379 kg, the Vikram lander 1,444 kg, including the Pragyan rover 27 kg.
The main purpose of Chandrayaan-3 is to safely land the lander on the moon's soil. Following
that, the rover will roll out to do the experiments. The life of the payload carried by the propulsion module post-ejection of the lander is between three and six months. On the other hand, the mission life of the lander and the rover is 1 Lunar day or 14 Earth days, ISRO said.
According to the Indian space agency, the propulsion module has a Spectro-polarimetry of Habitable Planet Earth (SHAPE) payload to study the spectral and Polari metric measurements of Earth from the lunar orbit.
The lander payloads are: Chandra’s Surface Thermophysical Experiment (ChaSTE) to measure the thermal conductivity and temperature; Instrument for Lunar Seismic Activity (ILSA) for measuring the seismicity around the landing site; Langmuir Probe (LP) to estimate the plasma density and its variations. A passive Laser Retroreflector Array from NASA is accommodated for lunar laser ranging studies.
On the other hand, the rover will carry an Alpha Particle X-ray Spectrometer (APXS) and Laser Induced Breakdown Spectroscope (LIBS) for deriving the elemental composition in the vicinity of the landing site, ISRO said.
The Friday moon mission is a follow-up of the failed Chandrayaan-2 mission in 2019 when the lander named Vikram crashed onto the moon's surface in the final moments. The crash was later attributed to a software glitch. The moon’s south pole has been the target of other international missions as well, but no country has been successful as of yet. In 2019, Israel’s Beresheet crashed on the lunar surface, while more recently, a private Japanese lunar lander called Hakuto-R also failed to soft-land near the moon’s south pole.
The lunar south pole is considered a more challenging terrain to land on compared to the moon’s equator. The region, however, is fascinating to scientists as ice has been detected in its craters. Water is a critical resource for future explorations. Scientists also believe that the frozen water found in craters maybe billions of years old, and maybe untouched by the sun’s radiation and wind, and could help them understand the early solar system.
As regards the changes made in the lander this time as compared to the one that crash-landed on the moon during the Chandrayaan-2 mission, a senior ISRO official told IANS that the lander has four motors instead of five. The space agency has also carried out some changes in the software. Interestingly, ISRO is silent on naming the lander and rover this time around.
During the Chandrayaan-2 mission, the lander was named Vikram, and the rover Pragyan. The three key officials for the mission are Mission Director Mohan Kumar, Vehicle/Rocket Director Biju C Thomas, and Spacecraft Director Dr P Veeramuthuvel.
(With inputs from IANS)