Chandrayaan’s temperature rises, mission scientists not sweating yet

A significant rise in temperature inside Chandrayaan — as a result of the spacecraft getting nearer to the sun while going around the moon— is preventing India’s first lunar mission from entering into the operational phase.

The high temperatures are likely to continue at least till the middle of next month when the spacecraft will move sufficiently away from the sun for the heat to subside. Though this rise in temperature was entirely expected and not a cause for any concern, the scientists at the mission control in Bangalore are playing safe by not switching on all the instruments simultaneously so as to avoid further rise in temperature because of the internal heat generated by the functioning of these instruments.

“This rise and fall in temperature inside a satellite is a normal cyclical process. There is nothing unusual about it. But since this is the first cycle being faced by Chandrayaan, we are being extra cautious. We have decided to wait till the temperatures dip to bring the mission into the operational phase,” Mylswamy Annadurai, project director of Chandrayaan-I, told The Indian Express.

As of now, all but two of the instruments onboard have been switched on and tested. But at any given point of time, only one instrument has been operational.

Chandrayaan-I placed in lunar orbit

India's maiden moon mission --Chandrayaan-I--today entered the tricky lunar orbit after scientists successfully carried out a most critical manaoeuvre, 18 days after it was fired into outer space.
Space scientists at the Indian Space Research Organisation (ISRO) carried out the lunar orbit insertion by firing the liquid engines on board the spacecraft for 817 seconds.

"The lunar orbit insertion (LOI) began at 4:50 p.M. And lasted for 817 seconds (14 minutes)," ISRO spokesperson S Satish told PTI. The satellite has been placed in a 7,502 km X 500 km elliptical orbit around the moon, he said.

Heaving a sigh of relief, ISRO chief G Madhavan Nair said today's operation was the "most critical moment" in the mission.

"We have done it," a visbly happy Nair declared.

"For the last 20 minutes, almost all our hearts were at a standStill," Nair said from a ground centre near Bangalore.

The spacecraft, launched on October 22, had been placed in the Lunar Transfer Trajectory on November four.

The mission, orbiting the earth at a distance of 3,86,000 km, was commandeered from ISRO's Telemetry, Tracking and Command Network (ISTRAC) at Peenya on the outskirts of the city with aid from the Indian Deep Space Network (IDSN) at Byalalu.

Chandrayaan-I would now be lowered gradually and placed in a circular orbit at a distance of 100 km from the lunar surface. PTI

Chandrayaan 96 hours from moon's orbit

Chandrayaan spacecraft entered the main highway to the moon and began its 96-hour flight towards the lunar orbit.

It was the fifth and final orbit raising manoeuvre before the spacecraft entered the orbit on Saturday.

A jubilant Chandrayaan project director Mylaswamy Annadurai told TOI from Bangalore the spacecraft's 440 Newton liquid engine was fired for about two-and-a-half minutes and Chandrayaan entered the moon highway with an apogee (farthest point to earth) being 3,80,000 km.

Annadurai recalled the final moments before the spacecraft entered the moon highway also known as lunar transfer trajectory. "I was at Isro's telemetry, tracking and command network (Istrac) at Bangalore since early morning and we were going step by step very carefully. As soon as we received a signal that Chandrayaan had successfully entered the main highway to the moon, there was a jubilation in the mission control room," he said. Istrac director S K Shivakumar told TOI, "Yes, we all had a sense of satisfaction, but let me tell you that there were no clapping and embracing because the lunar orbit insertion (LOI) was still left," Shivakumar said.

He said commands are flashed to the spacecraft in the form of a digital message. "The return key in a keyboard
is hit and the message is processed by the computer and transmitted to the spacecraft. Let me assure you that the person who will be hitting this return key on Saturday for the LOI is under no pressure," he said.

Annadurai said the health of the spacecraft was being continuously monitored from the spacecraft control centre at Istrac with support from the Indian Deep Space Network antennas at Byalalu. "I am happy to say that the spacecraft is performing normally," Annadurai said.

Asked if the Chandrayaan team was nervous about the LOI on Saturday, he said the orbit raising manoeuvre on Tuesday was equally crucial. "I am hoping that the manoeuvre will go off smoothly on Saturday too," he said.

He said in all probability the LOI will occur between 5pm and 6pm on Saturday. Space scientists said this manoeuvre can be a hair-raising one because 30% of lunar missions of US and the former Soviet Union have failed because of some problems during LOI.