Chandrayaan-3 lander serving as location marker near lunar south pole

An instrument on Chandrayaan-3 lander has started serving as a location marker near the lunar south pole, the ISRO said on Friday.

The Laser Retroreflector Array (LRA) on the Chandrayaan-3 lander has begun serving as a fiducial point (precisely located markers for reference) on the Moon, the national space agency headquartered here said in a statement.

US space agency 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, it said.

"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.

NASA's LRA was accommodated on the Chandrayaan-3 Vikram lander under international collaboration.

It comprises eight corner-cube retroreflectors on a hemispherical support structure. This array facilitates lasers ranging 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.

Landed near the lunar south pole on August 23, 2023, Chandrayaan-3's Vikram lander has been accessible for LOLA measurements since then, ISRO said.

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 the only one available near the south pole currently, the statement said.

"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 said.

These measurements, apart from aiding in precise determination of spacecraft's orbital position, will help refine the lunar geodetic frame, revealing insights into the Moon's dynamics, internal structure, and gravitational anomalies, it was noted.