DELHI: Many moons after it purportedly went missing, India’s first lunar probe - the Chandrayaan-1 - has been located by NASA.
The Indian Space Research Organisation (ISRO) lost contact with the spacecraft in August 2009, nearly a year after it was launched into orbit. It was assumed to have crashed into the moon. Up till then, the Chandrayaan-1’s most significant discovery was water molecules on the moon’s surface, NDTV had reported.
Eight years later, scientists at NASA’s Jet Propulsion Laboratory in California announced that they located it with a new interplanetary radar technique. Their calculations indicated that the Chandrayaan-1 is still circling about 200km above the lunar surface, they said in a blog post last Thursday (Mar 9).
NASA also managed to find its Lunar Reconnaissance Orbiter with the same technique, but said locating the Chandrayaan-1 required “a bit more detective work”.
At 1.5m on each side, the cube-shaped Indian lunar probe is “very small”, about half the size of a car.
“Although the interplanetary radar has been used to observe small asteroids several million miles from 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. Chandrayaan-1 proved the perfect target for demonstrating the capability of this technique,” NASA said.
HOW THEY FOUND THE CHANDRAYAAN-1
The radar team worked off knowledge that the Chandrayaan-1 had been in polar orbit.
Said NASA: “On Jul 2, 2016, the team pointed Goldstone and Green Bank at a location about 100 miles (160km) above the moon's north pole and waited to see if the lost spacecraft crossed the radar beam.
"Chandrayaan-1 was predicted to complete one orbit around the moon every two hours and eight 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.”
Using data from the return signal to estimate the velocity and distance to the target, they updated their orbital predictions and found that the Chandrayaan-1’s orbit “still had the shape and alignment that we expected".
NASA said the new radar technique could assist planners of future moon missions.
The father of India's moon mission, Krishnaswamy Kasturirangan, was quoted by the Times of India as saying: "To be declared lost and then found after eight years is a great accomplishment. Chandrayaan-1 was our first interplanetary mission and I am delighted that it has been found."
Still, do not expect the lunar probe to come back to life. As it is dormant and not sending data, the Chandrayaan-1 is as good as space junk, experts told NDTV.