Chandrayaan-1 was India’s first lunar mission and it was a successful one. The mission consisted of an orbiting spacecraft and a lunar impactor. The mission was designed to last two years, but the Indian Space Research Organisation (Isro) lost contact with the orbiter after almost a year in operation.
The Chandrayaan-1 mission payload was launched from the Satish Dhawan Space Centre on 22 October 2008 aboard the PSLV-XL C11 rocket. The orbiter was inserted into lunar orbit on 8 November 2008 and was expected to remain operational until at least 2010.
Sadly, the orbiter started experiencing technical issues with the star sensors, thermal shielding and more. On 29 August 2009, Isro lost contact with the spacecraft.
While the mission might appear to be a partial failure, it must be remembered that this was the mission that confirmed the presence of water on the surface of the moon.
Isro lost touch with the spacecraft, but that didn’t mean that the spacecraft had disintegrated or crashed into the surface of the moon. The National Aeronautics and Space Administration (Nasa) decided to “find” the Chandrayaan-1 orbiter to test some new tracking hardware that was being developed.
The tracking hardware involves an Earth-based radar system that Nasa has been using to track asteroids. They used this radar to pinpoint the location of Nasa’s own Lunar Reconnaissance Orbiter (LRO), but this was easy as they had precise orbital data for the LRO.
Isro’s Chandrayaan-1 orbiter, however, was incommunicado since 2009 and its orbital decay or drift was unknown. Nasa points out that the orbiter was also very small.
The moon is 380,000 km away from us, not a small distance, and the radar had to be very powerful. Nasa used a 70 metre antenna to beam microwaves to the moon and then analysed the returning radar echoes as they were received on a 100-meter telescope.
Nasa scientists predicted the orbit of Chandrayaan-1 and targeted the microwave beam in the area where they expected to see the spacecraft. They found it. Nasa tracked the spacecraft at regular intervals over the course of three months and now have precise data on its velocity and trajectory.
Of course, the spacecraft itself can’t be recovered, it’s in lunar orbit after all, but Nasa’s findings prove that they have the capability of tracking even tiny spacecraft at great distances from the Earth.