In a groundbreaking achievement, NASA’s Lunar Reconnaissance Orbiter (LRO) has successfully pinged India’s Chandrayaan-3 mission’s Vikram lander using a cutting-edge laser instrument. The significant development occurred as the laser beam was transmitted and reflected between the LRO and a compact device, similar to an Oreo in size, on the Vikram lander.
Situated 100 kilometers away from the LRO near the Manzinus crater in the Moon’s south pole region, the Vikram lander became the focal point for NASA’s revolutionary laser pulse technique on December 12 of the previous year.
This innovative method involves sending laser pulses from a moving spacecraft to a stationary one, precisely determining its location by measuring the time it takes for the light to bounce back.
The successful implementation of this technique opens up new possibilities for accurately locating targets on the Moon’s surface. Traditionally used for tracking Earth-orbiting satellites from the ground, this reverse application showcases its potential for various lunar missions.
Xiaoli Sun, leading the team at NASA’s Goddard Space Flight Center responsible for developing the retroreflector on Vikram, expressed the significance of the achievement. “We’ve shown that we can locate our retroreflector on the surface from the Moon’s orbit,” Sun stated. The next phase involves refining the technique to make it a routine practice for future missions utilizing retroreflectors.
The laser retroreflector, a mere 2 inches wide and called the Laser Retroreflector Array, boasts eight quartz-corner-cube prisms arranged in a dome-shaped aluminum frame. Simple, durable, and requiring no power or maintenance, this device can endure for decades. Its unique configuration enables it to reflect light from any direction back to its source.
Retroreflectors, a staple in lunar science and exploration since the Apollo era, have multifaceted applications. In this context, NASA’s retroreflector not only confirmed the success of the laser pulse technique but also serves as a fiducial point on the Moon for precise reference markers.
ISRO, the Indian Space Research Organization, acknowledged the achievement and highlighted the Laser Retroreflector Array (LRA) on the Chandrayaan-3 lander’s new role as a fiducial point on the Moon.
NASA’s LRO, utilizing the Lunar Orbiter Laser Altimeter (LOLA), achieved a laser range measurement by detecting signals reflected by the LRA on December 12, 2023, even during lunar night time. This remarkable progress represents a significant leap in lunar exploration capabilities and sets the stage for future missions utilizing similar technology.