Chandrayaan-3, India’s third lunar mission, achieved a historic feat on August 23, 2023, when it successfully landed its Vikram lander near the south pole of the Moon. The lander, named after the father of the Indian space program Dr Vikram A Sarabhai, carried a rover called Pragyan, which means ‘wisdom’ in Sanskrit. The lander and the rover were designed to conduct scientific experiments and exploration on the lunar surface for 14 Earth days.
The Vikram lander had a crucial role in Chandrayaan-3, as it was responsible for making a soft landing on the Moon and deploying the Pragyan rover. The lander was equipped with several advanced technologies, such as a Hazard Detection and Avoidance system, Laser & RF-based Altimeters, Laser Doppler Velocimeter, and Lander Horizontal Velocity Camera. These instruments helped the lander to navigate through the challenging terrain and select a safe landing spot.
The lander also carried three scientific payloads: RAMBHA-LP, ChaSTE, and ILSA. RAMBHA-LP measured the density and variation of plasma near the lunar surface. ChaSTE recorded the temperature characteristics of the lunar surface near the poles. ILSA detected seismic activity near the landing area and mapped the composition of the lunar crust and mantle.
After landing, the Vikram lander released the Pragyan rover, which rolled out of a ramp and started its journey on the Moon. The rover had two scientific payloads: APXS and LIBS. APXS analyzed the elemental composition of rocks and soil using X-ray fluorescence spectroscopy. LIBS identified minerals and elements using laser-induced breakdown spectroscopy.
The Vikram lander also served as a communication link between the Pragyan rover and Earth. The lander relayed data and images collected by the rover to the Chandrayaan-3 orbiter, which then transmitted them to ISRO’s ground station.
The Vikram lander also became a permanent landmark on the Moon, as it positioned itself as a fiducial point or a precisely located reference marker on the lunar surface. The lander’s Laser Retroreflector Array (LRA), a sophisticated instrument comprising eight corner-cube retroreflectors, was used by NASA’s Lunar Reconnaissance Orbiter (LRO) to perform precise laser range measurements. This experiment not only demonstrated international collaboration in space but also enhanced our understanding of the Moon’s dynamics, internal structure, and gravitational anomalies.
The Vikram lander’s role in Chandrayaan-3 was vital for advancing India’s space ambitions and contributing to global lunar science. The lander showcased India’s technological prowess and scientific curiosity in exploring the unknown frontiers of space.