For the very first time on the lunar surface, a laser beam has been effectively transmitted and reflected between an orbiting NASA spacecraft and a device the size of an Oreo located on the Indian Space Research Organisation's Vikram lander as part of India's Chandrayaan-3 mission.
In separate statements, both space agencies confirmed the success of this groundbreaking experiment. This achievement now paves the way for a novel method of precisely determining the location of targets on the Moon's surface, as highlighted by the American space agency. The milestone occurred at 3 pm EST on December 12, 2023, when NASA's Lunar Reconnaissance Orbiter (LRO) directed its laser altimeter instrument towards Vikram. Positioned near the Manzinus crater in the Moon's south pole, the lander was 100 kilometres away from LRO when laser pulses were transmitted toward it.
Upon detecting reflected light from a minuscule NASA retroreflector positioned on Vikram, the orbiter successfully confirmed the effectiveness of the employed technique, as stated by the space agency. The method involves sending laser pulses towards an object and gauging the time it takes for the light to rebound, a widely utilised approach for tracking the locations of Earth-orbiting satellites from the ground.
However, employing this technique in reverse—sending laser pulses from a mobile spacecraft to a stationary one to ascertain its exact location—holds numerous potential applications, according to scientists.
The Laser Retroreflector Array (LRA) on the Vikram lander has begun serving fiducial points (precisely located markers for reference) on the moon, ISRO said in a statement.