Heat stroke killed Chandrayaan-1
SEP 11, 2009
DOI: 10.1063/PT.5.023673
The Times of India : Contrary to India’s space agency ISRO’s explanation that Chandrayaan-1 ‘s orbit around the Moon had been raised from 100 km to 200 km in May this year for a better view of the Moon’s surface, it is now known that this was because of a miscalculation of the Moon’s temperature that had led to faulty thermal protection. As stated in the Times of India:
Admitting this, T K Alex, director of the ISRO Satellite Centre in Bangalore, said, “We assumed that the temperature at 100 km above the Moon’s surface would be around 75 degrees Celsius. However, it was more than 75 degrees and problems started to surface. We had to raise the orbit to 200km."On May 19, however, ISRO said it had raised Chandrayaan’s orbit 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."It now transpires that heating problems on the craft had begun as early as November 25, 2008, forcing ISRO to deactivate some of the payloads—there were 11 in all.As a result, some of the experiments could not be carried out which raised questions on whether the pre-launch thermal vacuum test done on the spacecraft at the ISRO Satellite Centre in Bangalore was adequate.
Sources at NASA headquarters told Physics Today last year that they were concerned with the documentation and test results provided by ISRO for integrating two NASA-funded experiments onto the spacecraft: M 3, the Moon Mineralogy Mapper , and miniSAR , a Synthetic Aperture Radar system to search for lunar polar ice.
© 2009 American Institute of Physics
