On Friday Morning (July 14), Indian Space Research Organization launched its third lunar exploration mission named India’s Chandrayaan-3 to explore the south pole of the moon. Chandrayaan-3 mission consists of a propulsion system, a robotic lander, and a rover. The mission which was launched from India’s Satish Dhawan Space Centre is expected to land on the moon on August 23 or August 24, if the space vehicle didn’t face any challenges in deep space.
If ISRO succeeds with its Chandrayaan-3 mission, it will make India become the fourth nation to soft-land a probe on the lunar surface after the Soviet Union, the United States, and China. The Indian Space Research Organization has projected three main goals for its Chandrayaan-3 mission. These objectives set for USD 77 million lunar mission include a safe soft landing close to the lunar south pole, safe deployment of a robotic rover, and demonstration of its operations on the lunar terrain.
The last goal of this mission is to conduct in-situ scientific experiments on a single lunar day of operation (which is equivalent to about 14 Earth days). However, before the Chandrayaan-3 space vehicle arrives in lunar orbit to carry out these ISRO’s goals, the spacecraft has to pass through a series of steps.
How ISRO’s Officials Plan to Soft Land India’s Chandrayaan-3 Lunar Rover aboard the moon surface
ISRO carefully created a unique workable plan to safely soft land the Chandrayaan-3 on the lunar surface. The Indian Space Agency divided the 40-day journey of its Chandrayaan-3 to the lunar surface into three segments including the Earth-centric phase, the lunar transfer phase, and the moon-centric phase.
Earth-centric phase
The first phase of this mission commences with the prelaunch, launch, and ascent session which was accomplished by the successful liftoff and safe separation of the Chandrayaan-3 from its ascent rocket. The space vehicle is currently in the Earth-bound maneuver stage, implying that Phase 1 is partially over.
During this last stage of phase 1, the Chandrayaan-3 is planned to conduct five orbits around Earth. After completing each orbit, the space vehicle will boost its distance away from our home planet. At the completion of the fifth orbit, the Chandrayaan-3 will enter the lunar transfer trajectory, thus pushing it further to the lunar transfer phase.
Lunar Transfer Phase
During the lunar transfer phase, the Chandrayaan-3 will leave Earth’s orbit and safely move into the lunar orbit. The spacecraft will make this transfer after it has completed the fifth and final orbit around Earth. Once it enters the lunar orbit, it will enter the last phase of the mission, which is the moon-centric phase.
Moon-centric Phase
During the moon-centric phase, the Chandrayaan-3 will conduct four orbits around the moon. The spacecraft will move closer to the lunar surface at the completion of each orbit. ISRO didn’t project the Chandrayaan-3 to land on the lunar surface once it enters the moon’s orbit. This is because the lunar wispy atmosphere makes it challenging in slowing down the speed of spacecraft during a landing stage.
Unlike the Earth’s thick atmosphere that slows down the speed of a spacecraft during its descent stage, the moon’s atmosphere does not give our spacecraft the same advantage. Hence, space agencies looking forward to a safe landing must slow down the spacecraft and descent following a slower approach. Chandrayaan-3 is designed to conduct an engine burn that will take it into a circular orbit of about 62 miles (100 kilometers) over the lunar surface.
The robotic lander and rover vehicles will gradually separate from the propulsion module and begin to descend to the lunar surface. ISRO planned to soft land the lander and rover in the lunar south pole region at a speed below 5 mph (8 kph). The Indian Space Agency also projected the propulsion module of Chandrayaan-3 to remain in orbit and communicate with the rover and the lander.
ISRO planned to use the orbiters from its Chandrayaan-2 mission which arrived on the moon in 2019 as a backup communications relay for its Chandrayaan-3 vehicles. Even though the Chandrayaan-2 mission arrived in the lunar orbit with a lander and rover, they both crashed during the touchdown phase of the mission in September 2019. Hence, ISRO planned the Chandrayaan-3 to achieve a safe landing.
The Future of ISRO India’s Chandrayaan-3 on the Lunar Surface
ISRO hopes for a fascinating future on the lunar surface. During an interviewing session with Times of India, ISRO Chairman Sreedhara Panicker Somanath explained that Chandrayaan-3’s solar-powered lander and robotic rover will touch down on the lunar surface in late August.
“Landing will be on August 23 or 24, as we want the landing to happen when the sun rises on the moon, so we get 14 to 15 days to work,” he said. “If landing cannot happen on these two dates, we’ll wait for another month and land in September.”
ISRO built the Chandrayaan-3 lander with its own thruster system, guidance and navigational controls, hazard detection, and avoidance systems.
After the Chandrayaan-2 crash, ISRO focused on implementing several changes on its Chandrayaan-3 space vehicle to ensure that it succeeds with this forthcoming mission. Somanath revealed that these improvements in this latest space vehicle include landing-speed tolerance, boosting the strength of the lander’s legs, and implementation of new sensors to calculate the approach speed of the spacecraft. Immediately after the space probe safely touches down on the lunar surface, the Chandrayaan-3 rover will emerge to commence its lunar exploration.
How ISRO Equip Its India’s Chandrayaan-3 lunar exploration vehicles to Study the lunar surface
India’s Chandrayaan-3 rover has its unique scientific payloads to study the lunar surface which include the LASER Induced Breakdown Spectroscope (LIBS) and the Alpha Particle X-ray Spectrometer (APXS). The LIBS payloads will land on the moon with technologies that will study the chemical composition of the lunar surface. The Alpha Particle X-ray Spectrometer (APXS) will focus on studying the lunar rocks and soil around the Chandrayaan-3 landing sites.
While the rover conducts its scientific exploration across the lunar terrain, the lander will deploy its Radio Anatomy of Moon Bound Hypersensitive Ionosphere and Atmosphere (RAMBHA) instrument in measuring the plasma, which is a gas of electrons and ions at the moon’s surface. The lander will also study how the plasma changes over a specific period of time. The lander also has Chandra’s Surface Thermophysical Experiment (ChaSTE) which will be used in measuring the thermal properties of the south pole region.
The Instrument for Lunar Seismic Activity (ILSA) will study the moon’s seismicity which will be useful in studying the structure of the lunar crust and mantle. NASA also contributed to this mission with its LASER Retroreflector Array (LRA), which will be operating as a passive experiment in the background on the lander. Hence, the LRA experiment will focus on gathering data that will be beneficial to scientists studying the dynamics of the moon.
Conclusion
India’s Chandrayaan-3 mission is currently on its way to the lunar surface. The spacecraft will likely land on the lunar surface in late August 2023. The success of this mission will make India become the fourth nation to land a space probe on the lunar surface. India’s Chandrayaan-3 mission will focus on conducting several scientific studies on the lunar surface. What do you think about this upcoming mission?
