(Image source from: Twitter.com/isro)

Chandrayaan-3's Vikram lander now serving as Moon's South Pole location marker:- The recent achievement of transmitting and reflecting a laser beam between ISRO's Vikram lander and NASA's Lunar Reconnaissance Orbiter (LRO) has significant implications for future space missions. This successful experiment opens up opportunities for accurately locating targets on the moon's surface.

On December 12, the LRO directed its laser altimeter instrument towards a small retroreflector on the Vikram lander. Positioned 100 kilometers away from the LRO, near the Manzinus crater in the moon's South Pole region, the Laser Retroreflector Array (LRA) on the Vikram lander effectively reflected the light back to the LRO. This retroreflector was fitted on the lander through an international collaboration between NASA and ISRO.

The LRA is a compact device, measuring only 5 cm wide. It consists of eight quartz-corner-cube prisms arranged within a dome-shaped aluminum frame. This design allows the retroreflector to efficiently reflect incoming light back to its source, regardless of the direction of the light. It is a simple and durable method that minimizes light scattering.

Retroreflectors have various applications, including the ability to accurately determine the location of a stationary spacecraft from a moving one by sending laser pulses and measuring the time it takes for the light to bounce back. This technique, commonly used for tracking Earth-orbiting satellites from the ground, can now be reversed for space missions.

The LRA on the Vikram lander serves as a long-term geodetic station and a location marker on the lunar surface. It has a long lifespan and requires no maintenance or power source. Currently, the LRA on Chandrayaan-3 is the only retroreflector available near the moon's South Pole. Its presence will benefit current and future lunar missions, as it provides a precise and reliable method for determining location on the moon.

Overall, this achievement in laser beam transmission and reflection between the Vikram lander and LRO sets the stage for improved navigation and targeting capabilities in future lunar missions. It marks a significant step forward in space exploration technology and collaboration between international space agencies.