India’s first moon-craft, Chandrayaan-I, has been weighed down by a glitch, raising doubts about the longevity of the spacecraft as well as its two-year mission.
One of the two star sensors onboard – gadgets that help the orbiter retain its orientation and focus on the lunar surface – has collapsed. An alternative system has been turned on to ensure that Chandrayaan-I does not drift away or crash into the moon. In addition, the orbiter has been pushed back from its original orbit at 100 km from the lunar surface to 200 km for enhanced control of the spacecraft.
The snag occurred on May 16 and the substitute system was activated within a week. “It (Chandrayaan-I) has a handicap. One of the star sensors has failed but we have onboard gyros (gyroscopes are used to maintain orientation and provide stability in boats, aircraft and spacecraft) to correct it. It is difficult to say how long it will last on an alternative system.
In some cases, spacecraft (with such substitute systems) have worked for five to 10 years,” said G. Madhavan Nair, chairman of the Indian Space Research Organisation (ISRO) at a press conference here on Friday.
Nair tried to play down the setback, stating that his colleagues handle such snags on any one of the 20 satellites manufactured and launched by ISRO. “We are as transparent as could be but every day some satellite or the other will have a problem. We share with you (media) our objectives and achievements in space. In this case, somebody has been snooping around. I cannot help it,” he said.
Besides, the spacecraft had achieved 90 to 95 per cent of the mission objective through 11 instruments on board, Nair said. “The scientific community has said the quality of data is excellent. They are satisfied with the volume and quality of data. What is yet to be completed is mapping of the (lunar) terrain and minerals on the moon. That is only 5 per cent, which will be completed soon,” Nair added.
The snag, however, will not delay the design and manufacture of Chandrayaan-II, a lander-rover mission scheduled for 2012. “This will prove a valuable input for the next spacecraft. We will build in some improvements so that this problem does not recur,” Nair said.