Wednesday, November 26, 2008

India moon craft hit by heat rise

By Swaminathan Natarajan
BBC Tamil service

Moon (ISRO)
The lunar surface viewed by the Moon Impact Probe on its descent

Indian scientists are exploring various options to cool down a sudden surge of temperature inside the country's first unmanned lunar craft, Chandrayaan 1.

The temperature inside the satellite has gone over 50C, prompting scientists to take drastic measures.

They say that the problem arose because of very hot temperatures during the lunar orbit.

The mission is regarded as a major step for India as it seeks to keep pace with other space-faring nations in Asia.

Earlier this month the spacecraft sent a probe onto the surface of the moon.

Urgent measures

"Now the moon, our satellite and the sun are in same line this means our craft is receiving 1,200 watts of heat from the moon and 1,300 watts from the sun per meter square," said M Annadurai, project director of Indian's moon mission.

CHANDRAYAAN 1
Infographic (BBC)
1 - Chandrayaan Energetic Neutral Analyzer (CENA)
2 - Moon Impact Probe (MIP)
3 - Radiation Dose Monitor (RADOM)
4 - Terrain Mapping Camera (TMC)
5 - Moon Mineralogy Mapper (M3)
6 - Chandrayaan 1 X-ray Spectrometer (C1XS)
7 - Solar Panel

If the temperature is not kept in check, many instruments on board the orbiter may fail to perform, scientists say.

This has prompted them to take urgent measures. Most of the instruments are now switched off or being used sparingly.

"We have rotated the spacecraft by 20 degrees and this has helped to reduce the temperature of the craft. We have also switched off certain equipment like mission computers and this has resulted in the reduction of temperature to 40C now. At this temperature all the equipment can perform very well," Mr Annadurai said.

"Although we did factor in the thermal conditions in the lunar orbit, the temperature is a bit higher than we anticipated."

He insisted all the instruments carried on board of the satellite have been tested and were working properly.

While the turning-off of certain equipment will have an impact on lunar research, Mr Annadurai said that it was not worth "taking the risk to run it" at present.

Scientists also plan to raise the orbit of the Indian craft to cool it down. It is presently in orbit 100km (62 miles) from the moon. However Mr Annadurai said that would only be done as a last resort.

He said that the next month would be critical for the survival of the mission, which has an intended life span of two years.

"We are able to use terrain mapping cameras to take picture of the moon whenever required," Mr Annadurai said.

India launched its first lunar mission on 22 October. The mission aims to map the lunar surface, look for traces of water and the presence of helium.

The current difficulties are the first to be experienced by the probe, which has been praised for sending the probe onto the moon's surface.

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