G.S. MUDUR

New Delhi, Aug. 29: India’s first moon mission ended prematurely today with engineers losing radio contact with Chandrayaan-1 after months of struggle to cling on to a troubled spacecraft threatening to slip beyond control.

The Indian Space Research Organisation lost contact with the Rs 380-crore spacecraft 10 months into its intended two-year mission that helped India gain experience in a deep space venture yet humbled Isro by its challenges.

The space agency said the Isro Deep Space Network station near Bangalore lost radio contact with Chandrayaan-1 abruptly at 1.30am on Saturday after receiving routine housekeeping telemetry signals from the spacecraft until 12.25am.

During that hour, the spacecraft would have moved to the moon’s far side, and radio silence was expected, a senior official said. “We expected to pick up telemetry at 1.30am which never came,” the official said.

Engineers at the Deep Space Network today analysed the last sets of telemetry data from the spacecraft in an attempt to understand better what might have happened, but sources indicated that the spacecraft mission was over.

The trouble on the spacecraft began months ago with the high temperature and electromagnetic radiation levels at its 100km lunar orbit appearing to cause problems with components involved in power distribution, the sources said.

Isro has not specified when exactly the problems began, but in May this year the agency raised the orbit of Chandrayaan-1 to 200km above the lunar surface where the environment would be less severe than at 100km.

The agency revealed in July that a star sensor — an electronic eye that helps point the antenna and cameras in the right directions — had malfunctioned and a set of backup electromechanical sensors called gyroscopes had been activated.

“The last three months have been attempts at salvaging the mission,” a senior Isro engineer told The Telegraph over the phone. “We now have no contact — and thus no control over the spacecraft.”

Chandrayaan-1 had 10 scientific payloads designed to capture images of the lunar terrain at unprecedented detail, search for minerals and ice and assess the lunar environment for future missions.

Isro chairman Madhavan Nair had said last month that 90 per cent of the mission objectives had been completed. But two senior scientists who have been involved in analysing the data received from the spacecraft declined to comment after The Telegraph requested them to quantify how much of the task had been completed over the past 11 months. “Ask Isro,” a senior scientist in a European country said.

Even in its 200km orbit, the spacecraft is locked in lunar gravity and required thruster firings to stay in orbit. Without such firings, Chandrayaan-1’s orbit will decay over time and the spacecraft will crash on the moon, an engineer said. (See graphic)

“This mission has been a success,” said the engineer. “We put a spacecraft in lunar orbit in our very first attempt — spacecraft from other countries have missed the moon altogether. But we’ve also learnt lessons — we’ll need to use them for future missions.”