Calculations suggest that the spacecraft, "lost" since Aug. 2009, is still circling some 200 km above the lunar surface, but it was generally considered "lost."

NASA’s Jet Propulsion Laboratory, using a new interplanetary radar technology, has spotted India's Chandrayaan 1, which has been out of radio contact since August 2009.

"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 of the test project, in a press note released by JPL on Thursday.

"Finding LRO was relatively easy, as we were working with the mission's navigators and had precise orbit data where it was located. Finding Chandrayaan-1 required a bit more detective work because the last contact with the spacecraft was in August 2009."

"Although the interplanetary radar has been used to observe small asteroids several million miles from the Earth, 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," the press note added.

Optical telescopes are unable to search for small objects hidden in the bright glare of the moon.

Chandrayaan-1, India’s first moon mission, was launched on October 22, 2008. It was successfully placed in a polar orbit around the moon on November 8, 2008. The Moon Impact Probe was placed on the moon on November 14, 2008, and with this India became the fourth country to touch the moon.

Analysing the soil collected by the impact probe, Indian scientists found evidence of the existence of water on the moon. The mission was expected to last for two years; however, after 312 days, it had to be closed, as the station lost track of the spacecraft on August 29, 2009.

Finding a dormant spacecraft around the moon is difficult, since its orbital path could have varied over time, or even crashed on the moon. JPL's calculations suggest that Chandrayaan-1 is still circling some 200 km above the lunar surface, but it was generally considered "lost."

As Chandrayaan-1 is in a polar orbit around the moon, the scientists aimed the radar at a location above the moon’s north pole and waited for the satellite to pass the radar beam. "Chandrayaan-1 was predicted to complete one orbit around the moon every two hours and 8 minutes. Something that had a radar signature of a small spacecraft did cross the beam twice during four hours of observations, and the timings between detections matched the time it would take Chandrayaan-1 to complete one orbit and return to the same position above the moon’s pole," the press note said. Seven more readings over the next three months confirmed that it is indeed Chandrayaan.

India's second moon mission Chandrayaan-2 is expected to be launched at the end of 2018.