NASA has been tracking missing spacecraft since 2009 with interplanetary radar
NASA has tracked down an Indian spacecraft missing since 2009 using interplanetary radar technology. It has been the biggest test of the technology to date and the demonstrated potential could be helpful in future lunar missions.
The spacecraft, the Chandrayaan-1, is an unmanned cube of about 1.5 cubic meters and has yet to orbit the moon. Detecting the vehicle with telescopes proved impossible because the moon’s reflected light was too bright to see such a small object.
The interplanetary radar has been used for some time, for example, to observe asteroids that are millions of kilometers from Earth, according to NASA. Although Chandrayaan-1 floats through space at a distance of ‘only’ about 384,400 kilometers, its small size made detecting this object more challenging than usual asteroids. NASA also tracked down its own Lunar Reconnaissance Orbiter with the technology, but it wasn’t lost, so the agency had a very good idea of where to look.
NASA’s radar installation consists of two major parts. The microwaves are emitted from an antenna 70 meters in diameter at the Goldstone Deep Space Communications Complex in Fort Irwin, California. The rebounding waves are captured almost all the way across the country, by the 100-foot-wide Green Bank Telescope in West Virginia.
The search was complicated by the fact that the lunar gravitational pull is not equally strong, making it more difficult to estimate where the Indian spacecraft should have been. It could not even be ruled out that Chandrayaan-1 had already crashed on the moon. However, NASA knew that the spacecraft was moving over the moon’s poles and that has been the benchmark that led to its rediscovery.
This new application for interplanetary radar can be useful for both estimating collision risk and supporting space vehicles with communication and navigation problems.
Image: NASA