NASA's Deep Space Network Finds Silent Lunar Satellite
Mar 11 2017
Chandrayaan-1, which was India's first unmanned mission to the moon, has finally been found again - long after it was given up for lost. Indian Space Research Organisation (ISRO), who was the owner and operator of the lunar mission later declared the spaceship as "lost" after it mislaid communication with the spacecraft on 29th August 2009. Chandrayaan-1 is small - about half the size of a smart auto which makes its detection even more noteworthy. NASA's scientists were looking at the moon from Earth (a distance of 237,000 miles) attempting to find this tiny spec of an object. "Detecting Chandrayan-1 was tough because of its diminutive size which is about 1.5m on each side". According to Nair, the finding of the spacecraft in deep space by an Earth-based telescope deployed by NASA shows that "radar technologies have really advanced". Finding LRO was less of a challenge and more of a proof of concept; it's an active spacecraft, so precise location data from the mission's navigators guided the search, detection team members said. Scientists at Nasa's Jet Propulsion Laboratory said it required "more detective work" to find Chandrayaan-I after they spotted Nasa's Lunar Reconnaissance Orbiter (LRO). These are caused by regions of high density, called mascons, under the lunar surface, and can act like shifting currents do on a ship to send orbiting satellites off course as they revolve around the Moon.
An Indian spacecraft launched in 2008 to explore the moon was lost to scientists the next year. This antenna sent out a beam of microwaves which reached the moon and then the radar echoes bounced back from the orbit of the moon, being intercepted by the Green Bank Telescope in West Virginia.
NASA reported how it used the 70-meter antenna at the Goldstone Deep Space Communications complex in the Mojave Desert to detect India's Chandrayaan-1, which lost contact with earth nearly a decade ago. On July 2 previous year, the scientists pointed two antennas, one in California and the other in West Virginia, to a location about 160km above the Moon's north pole. Sure enough it did, and multiple detections over a three month period allowed NASA to confirm the object definitely is Chandrayaan-1.
"It turns out that we needed to shift the location of Chandrayaan-1 by about 180 degrees or half a cycle from the old orbital estimates from 2009", Ryan Park, manager of the JPL's solar system dynamics group, said in the release.
They were both orbiting the moon.
The main objectives of the Chandrayaan-1 were to test the impact of a sub-satellite (Moon Impact Probe - MIP) on the surface on the Moon as a fore-runner to future soft-landing missions and also to detect water-ice on the Moon.