NASA's LRO Laser Successfully Sends Signals to Indian Moon Lander

 

For the first time ever, scientists made a laser bounce between a NASA spacecraft and a small gadget on ISRO's Vikram lander on the Moon. This experiment could be a game-changer, helping us precisely find locations on the Moon's surface.

On December 12, 2023, at 3 p.m. EST, NASA's Lunar Reconnaissance Orbiter (LRO) aimed its laser at Vikram, which was about 62 miles away in the Moon's South Pole region. The laser pulses bounced off a tiny NASA retroreflector on Vikram, confirming the success of the technique.

This retroreflector, a Laser Retroreflector Array, is a small but robust device, only 2 inches wide. It has eight quartz-corner-cube prisms in a dome-shaped aluminum frame, reflecting light back to its source from any direction. This little gadget doesn't need power, maintenance, and can last for decades.

Using lasers to measure the time it takes for light to bounce back is a common method to track satellites from Earth. Now, scientists have reversed this technique, sending laser pulses from a moving spacecraft to a stationary one, helping precisely locate objects on the Moon.

Xiaoli Sun, leading the team at NASA's Goddard Space Flight Center, stated, "We've shown that we can locate our retroreflector on the surface from the Moon's orbit. The next step is to improve the technique for future missions."

These retroreflectors have various applications, from studying the Moon's movement to aiding spacecraft docking. The new, smaller retroreflectors, like the one on Vikram, could guide astronauts to the Moon's surface or mark locations for future landings.

However, there are challenges. The current laser instrument on LRO wasn't designed for this pinpointing task. LOLA, the altimeter, took eight tries to contact Vikram's retroreflector. It sends laser beams towards the Moon, measuring the time they take to bounce back to map the Moon's topography. But for precise targeting, a future laser system with continuous coverage is needed.

Despite challenges, NASA plans to use LRO's laser altimeter to refine surface target positions for now. Multiple NASA retroreflectors are scheduled for future Moon missions, including one on JAXA's SLIM lander and another on a private spacecraft by Intuitive Machines, both part of NASA's Commercial Lunar Payload Services initiative.

In essence, this successful laser experiment opens new possibilities for lunar exploration and research, paving the way for future missions to the Moon's surface.