NASA’s recent discovery that India’s Chandrayaan I is still in orbit around the moon comes as no big surprise, G Madhavan Nair, the former chairman of the Indian Space Research Organisation (ISRO) and the key figure behind the Chandrayaan I mission, has said. “The big achievement here is the advancement made in NASA’s radar systems. That they could track our tiny spacecraft from approximately 400,000 km away is a big achievement,” Madhavan Nair said.
ISRO launched the Chandrayaan I mission on October 22, 2008, from Sriharikota, but after 312 days in orbit around the moon, the space agency had lost contact with it – in August 2009. Shortly afterwards, ISRO declared the mission over. Recently, more than seven years later, NASA’s ground-based probe had managed to locate the spacecraft still in orbit around the moon.
“Back then, we had predicted a two-year life for Chandrayaan I. But we lost contact after a power system failure,” Madhavan Nair recalled.
According to ISRO, “the satellite made over 3,400 orbits around the moon and the mission was concluded when the communication with the spacecraft was lost on August 29, 2009.”
So why doesn’t the NASA discovery come as a surprise? Satellites burn up in the atmosphere after atmospheric drag reduces velocity, pointed out Madhavan Nair. For instance, a satellite in a 200 km orbit around the earth would burn up in the earth’s atmosphere in 30 or so days due to the drag effect. But since the moon lacks any real atmosphere, technically Chandrayaan I could stay in orbit for hundreds of years, he said.
NASA’s technology which helped it locate the Chandrayaan I would come in handy in tracking meteors and other celestial objects, Madhavan Nair said.
Chandrayaan aside, NASA’s radar had also managed to locate its own Lunar Reconnaissance Orbiter.