In a groundbreaking science experiment, NASA's Lunar Reconnaissance Orbiter (LRO) fired a laser at India's Vikram rover on the moon. Contrary to all the implications of space warfare, this carefully planned experiment was intended to test the accuracy of locating a small target on the surface of the Moon.
The laser, originating from LRO in lunar orbit, traveled an impressive 100 kilometers to hit a target just 5 cm wide - the Laser Retroreflector Array, about the size of an Oreo cookie. Mounted on the Vikram lander of the Indian Space Research Organization (ISRO), this reflective array served as the focus of the experiment.
The laser beam, after hitting the array, returned to LRO, demonstrating the potential for pinpointing the precise location of stationary objects on the Moon. Using light reflected to and from satellites is common practice on Earth for orbit tracking.
The success of this experiment could pave the way for future missions that want to use such reflectors for position accuracy. Mission leader Xiaoli Sun of NASA's Goddard Space Flight Center emphasized the significance of the experiment, stating, "We have shown that we can locate our retroreflector on the surface from lunar orbit.
" Sun added that the next step is to refine the technique so that it becomes routine practice for future missions using similar reflectors. Vikram Spotlight was developed through collaboration between NASA and ISRO. It is significant that this device is completely optical, requiring no power supply or maintenance.
Its ability to reflect light from any direction ensures that Vikram's exact location can be re-identified for decades to come, despite the rover being no longer functional.
Importance of experiment for science
In addition to immediate experimental success, such tests contribute to broader knowledge about the Moon.
Experiments like this help scientists understand the Moon's dynamics, such as its gradual drift away from Earth by 3.8 centimeters per year. NASA used its Lunar Orbiter Altimeter (LOLA) for this experiment, although LOLA was not originally designed for such precise targeting.
Daniel Cremons, a NASA scientist, acknowledged the challenge of hitting a small target with LOLA, which typically focuses on an area 10 meters wide. Despite taking eight tries, LOLA successfully hit the Vikram spotlight. This achievement opens the door to potential future lunar missions where retroreflectors will be included as a key technology.