Panaji: India’s first Moon mission became casualty of unforeseen high temperatures that led to faulty thermal protection.
In May this year, the orbit of the spacecraft was raised to 200kms from 100 kms from the surface of the Moon. Scientists had then said it was done for a better view and to enable further studies on orbit perturbations, gravitational field variation of the Moon and also enable imaging of the lunar surface with a wider swath.
But Dr T K Alex, director, ISRO Satellite Centre, Bangalore revealed on Sunday that the orbit was raised to escape the surface heat which was above 75 degrees Celsius. It was this that led to the failure of two star censors in July. These censors were responsible for the orientation of Chandrayaan and the scientists were operating the spacecraft using ingenious ways.
The thermal issue reportedly appeared in November, forcing ISRO to deactivate some payloads. Officials also said scientists had foreseen that the mission would fail before the official announcement made on August 25. The mission had accomplished 95% of its objectives and had sent excellent images including that of the solar eclipse on July 22.
Top European and American space scientists will join their Indian counterparts in Bangalore on Monday to review the performance of India`s maiden moon mission Chandrayaan-1 that was aborted prematurely last week, a senior space agency official said Sunday.
"Scientists from the European Space Agency (ESA), the National Aeronautics and Space Administration (NASA) and the Bulgarian Academy of Sciences will review the performance of their payloads (scientific instruments) that were onboard the spacecraft along with our payloads," Indian Space Research Organisation (ISRO) director S Satish told news agencies.
Chandrayaan was launched Oct 22, 2008 from spaceport Sriharikota, about 90 km northeast of Chennai, with 11 scientific instruments, including three from ESA, two from NASA and one from Bulgaria. The remaining five were from the Indian space agency ISRO.
"At the day-long closed-door review meeting, to be presided over by ISRO chairman G. Madhavan Nair, the scientists of the respective space agencies will present the results, consisting of data, pictures and analysis for a detailed discussion of the 10-month-old mission, which had scientific and technology objectives," Satish said.
The meeting, however, will not go into the reasons for terminating the mission abruptly after repeated attempts to restore communication link with the spacecraft by the space agency`s telemetry, tracking and command network (Istrac) here failed.
The ESA`s three payloads were the imaging x-ray spectrometer (C1XS), the smart infrared spectrometer (SIR-2) and sub kiloelectronvolt (keV) atom reflecting analyzer (SARA).
Similarly, the US payloads were the 6.5kg mini synthetic aperture radar (MiniSAR) and the moon mineralogy mapper (M3).
The lone Bulgarian payload was the radiation dose monitor (RADOM).
The five Indian payloads were the terrain mapping camera (TMC), the hyper spectral imager (HySI), the lunar laser ranging instrument (LLRI), the high energy x-ray spectrometer (HEX) and the moon impact probe (MIP).
"We have achieved the technology objectives of the mission by flying the spacecraft 400,000km to the moon, inserting into the lunar orbit and placing the Indian tricolour on the lunar surface Nov 14 without hitch," Satish noted.