NASA’s spacecraft circling the Moon has made a groundbreaking connection with India’s Chandrayaan-3 mission, announcing a successful laser interaction between the Lunar Reconnaissance Orbiter (LRO) and Vikram lander. The laser beam, transmitted and reflected by an Oreo-sized device on the Vikram lander, marks a significant advancement in precisely locating targets on the lunar surface, according to NASA.
Situated 100 kilometers away from the LRO, near the Moon’s south pole region and the Manzinus crater, the Vikram lander received laser pulses from the orbiter on December 12 of the previous year. NASA scientists confirmed the success of their technique when the orbiter detected reflected light from a small NASA retroreflector on Vikram.
The approach of sending laser pulses from a moving spacecraft to a stationary one, measuring the light’s travel time, is commonly used to track Earth-orbiting satellites. However, applying this technique in reverse—locating a stationary object from a moving spacecraft—holds numerous applications for lunar exploration, scientists explained.
Lead researcher Xiaoli Sun from NASA’s Goddard Space Flight Center, responsible for developing the retroreflector on Vikram in collaboration with the Indian Space Research Organization (ISRO), expressed optimism about the achievement. Sun emphasized the need to enhance the technique for routine use in future missions utilizing these retroreflectors.
NASA’s Laser Retroreflector Array, a compact yet powerful device measuring only 2 inches (5 centimeters) wide, features eight quartz-corner-cube prisms in a dome-shaped aluminum frame. Known for its simplicity and durability, the retroreflector requires no power or maintenance, ensuring a long lifespan. Its design enables it to reflect light from any direction back to its source.
Retroreflectors, a proven technology dating back to the Apollo era, serve various scientific and exploratory purposes. NASA highlighted their use in revealing that the Moon is gradually moving away from Earth at a rate of 3.8 centimeters per year.
In response to this milestone, ISRO announced that the Laser Retroreflector Array on Chandrayaan-3’s lander is now serving as a fiducial point, offering precisely located markers for reference on the Moon. ISRO confirmed the success of the laser range measurement conducted by NASA’s Lunar Reconnaissance Orbiter, utilizing the Lunar Orbiter Laser Altimeter on December 12, 2023, during lunar night time.
