Radiation Ruination To Be Avoided On Chandrayaan-II, Says ISRO

The intense radiation from the sun that roasted India’s first unmanned lunar satellite’s key orientation instrument — the star sensor — has raised concerns over the safety of Indian astronauts on the country’s first manned space flight, planned around 2015.

A scientist from the Indian Space Research Organisation (ISRO) pointed out that radiation can kill astronauts if the emissions from the sun are intense. Scientists at ISRO are taking no chances. Chandrayaan program director M. Annadurai stated the organization is looking at “increasing the thickness of the radiation shield for Chandrayaan-II.” The star sensor failure has forced the ISRO to rework their design. The improvised radiation shield will protect the next unmanned moon mission, Chandrayaan-II, scheduled for 2012-13. ISRO scientists say the shield for Chandrayaan-II will be a tester for the manned space flight. ISRO wants to send two Indian astronauts for about a week into an Earth orbit.

Scientists plan to land a robotic rover that will explore the lunar surface in their Chandrayaan-II mission. They are now awaiting the conclusion of ISRO’s review meeting to take stock of the Chandrayaan-I mission, including the failure of the star sensors, which will be held later this year. Annadurai admitted that as this was the first time that India had sent a satellite into a close lunar orbit at an altitude of just 100 kms, “we have learned from our experience that we need to improve the radiation shield for the next mission.” At a distance of just 100km from the Moon’s surface, any lunar satellite receives an overdose of radiation, primarily the direct blasts from the sun, and secondarily, the reflected radiation off the moon’s surface. One of the avenues space scientists must deal with regarding high radiation threats to satellites is to completely close down the satellite’s operations. “But we cannot close down the star sensor as that would mean losing the orientation of the satellite, which is difficult to regain later,” said Annadurai. The star sensors keep the satellite pointed in a particular direction. This is a key instrument for satellites that can help the camera side pointed at the earth’s or moon’s surface.