NASA’s spacecraft sends signals to the Chandrayaan-3 lander located on the moon.
On December 12 of the previous year, the lander was positioned approximately 100 kilometers away from the Lunar Reconnaissance Orbiter (LRO) near the Manzinus crater in the Moon’s southern pole region. During this time, the LRO emitted laser pulses towards the lander.
In New Delhi, NASA reported that a laser instrument aboard one of its spacecraft orbiting the Moon has successfully communicated with the Vikram lander from India’s Chandrayaan-3 mission. According to the US space agency, the laser beam was sent and reflected between the Lunar Reconnaissance Orbiter (LRO) and a device on the Vikram lander, approximately the size of an Oreo. This development marks the initiation of a novel method for precisely locating targets on the lunar surface, as per NASA. The event took place when the lander was situated 100 kilometers away from the LRO near the Manzinus crater in the Moon’s south pole region, and laser pulses were directed towards it on December 12 of the preceding year.
Upon detecting reflected light from a small NASA retroreflector on the Vikram lander, scientists at NASA confirmed the success of their technique. The method involves sending laser pulses from a moving spacecraft to a stationary one, determining its precise location. While sending laser pulses towards Earth-orbiting satellites from the ground is common, this reverse technique holds significant applications for lunar missions, according to scientists. The retroreflector, known as the Laser Retroreflector Array, is a compact device featuring quartz-corner-cube prisms arranged in a dome-shaped aluminum frame. It requires no power, minimal maintenance, and can endure for decades. NASA intends to refine the technique for routine use in future missions employing retroreflectors.
Measuring only 2 inches wide, the retroreflector played a crucial role in indicating the Moon’s gradual distance increase from Earth—3.8 centimeters per year—by reflecting light back to Earth. The Laser Retroreflector Array on the Chandrayaan-3 lander is now functioning as a fiducial point, providing precise markers for reference on the Moon, as confirmed by the Indian Space Research Organization (ISRO). NASA’s Lunar Reconnaissance Orbiter (LRO) successfully utilized the retroreflector for laser range measurement, detecting signals reflected on December 12, 2023, during lunar night time. The Lunar Orbiter Laser Altimeter (LOLA) on the LRO was employed for the ranging, with the observation occurring as the LRO ascended to the east of Chandrayaan-3, according to ISRO.
