BENGALURU: An instrument on the Chandrayaan-3’s Vikram lander has started serving as a location marker near the lunar south pole, the Indian Space Research Organisation said on Friday. While several markers have been deployed on the Moon since the beginning of the lunar exploration, the one on Chandrayaan-3 is the only one available near the south pole currently.
Meanwhile, NASA in a statement said, “For the first time at the Moon, a laser beam was transmitted and reflected between an orbiting NASA spacecraft and an Oreo-sized device on ISRO’s lander on the lunar surface.” It added that this successful experiment opens the door to a new style of precisely locating targets on the Moon’s surface.
The Laser Retroreflector Array (LRA) was developed by NASA and accommodated on the Vikram lander under international collaboration. “NASA’s Lunar Reconnaissance Orbiter (LRO) achieved a laser range measurement using the LRA by successfully detecting signals reflected by it on December 12, 2023.
The ranging utilized the Lunar Orbiter Laser Altimeter (LOLA) on the LRO. The observation occurred during lunar nighttime, with the LRO ascending to the east of Chandrayaan-3,” said ISRO in a statement. Sending laser pulses toward an object and measuring how long it takes the light to bounce back is a commonly used way to track the locations of Earth-orbiting satellites from the ground.
The LRA on Vikram lander will continue to serve as a long-term geodetic station and a location marker on the lunar surface, benefitting current and future lunar missions that different countries will undertake. The space agency said, “These measurements, apart from helping in the precise determination of the spacecraft’s orbital position, will help refine the lunar geodetic frame, revealing insights into the Moon’s dynamics, internal structure and gravitational anomalies.”
The instrument comprises eight corner-cube retroreflectors on a hemispherical support structure. This array facilitates laser ranging from various directions by any orbiting spacecraft with suitable instruments. The passive optical instrument, weighing about 20 grams, has been designed to last for decades on the lunar surface.