Washington: Chandrayaan-1, the first lunar probe of India, has been found orbiting the moon. The space craft, which was considered lost after the Indian Space Research Organisation lost communication with it on August 29, 2009, has been found orbiting the moon by NASA, using a new ground-based radar technique. NASA’s Jet Propulsion Laboratory, situated in California, located the lunar probe still circling some 200 kilometres above the lunar surface.
“We have been able to detect NASA’s Lunar Reconnaissance Orbiter (LRO) and the Indian Space Research Organisation’s Chandrayaan-1 spacecraft in lunar orbit with ground-based radar,” said Marina Brozovic, a radar scientist at JPL and principal investigator for the test project.
Although the interplanetary radar has been used to observe small asteroids, researchers were not certain that an object of this smaller size as far away as the Moon could be detected, even with the world’s most powerful radars. But Chandrayaan-1 proved the perfect target for demonstrating the capability of this technique.
To find a spacecraft 380,000 kilometres away, JPL’s team used NASA’s 70-metre antenna at NASA’s Goldstone Deep Space Communications Complex in California to send out a powerful beam of microwaves directed towards the Moon.
Then the radar echoes bounced back from lunar orbit were received by the 100-meter Green Bank Telescope in West Virginia.
On July 2 last year, the team pointed Goldstone and Green Bank at a location about 160 kilometres above the Moon’s north pole and waited to see if the lost spacecraft crossed the radar beam.
“Finding LRO was relatively easy, as we were working with the mission’s navigators and had precise orbit data where it was located. Finding India’s Chandrayaan-1 required a bit more detective work because the last contact with the spacecraft was in August of 2009,” said Ms Brozovic.
The Chandrayaan-1 spacecraft is very small, a cube about 1.5 meters on each side – about half the size of a smart car. It was launched on October 22, 2008.