The US space agency NASA‘s Lunar Reconnaissance Orbiter (LRO) successfully detected signals reflected by the LRA on December 12, 2023, using laser range measurement, according to ISRO.
“The ranging utilised the Lunar Orbiter Laser Altimeter (LOLA) on the LRO. The observation occurred during lunar night time, with the LRO ascending to the east of Chandrayaan-3,” ISRO said.
Under international collaboration, NASA’s LRA was placed on the Chandrayaan-3 Vikram lander. It consists of eight corner-cube retroreflectors on a hemispherical support structure. This array enables lasers to range from various directions by any orbiting spacecraft with suitable instruments.
The passive optical instrument, weighing about 20 grams, is designed to last for decades on the lunar surface.
Since its landing near the lunar south pole on August 23, 2023, Chandrayaan-3’s Vikram lander has been accessible for LOLA measurements. ISRO mentioned that while several LRAs have been deployed on the Moon since the beginning of lunar exploration, the LRA on Chandrayaan-3 is a miniature version and is currently the only one available near the south pole.”NASA’s LRA on Chandrayaan-3’s 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,” ISRO added.
This will benefit current and future lunar missions. Besides aiding in the precise determination of the spacecraft’s orbital position, these measurements will also help refine the lunar geodetic frame, providing insights into the Moon’s dynamics, internal structure, and gravitational anomalies.