The Indian Space Research Organisation (ISRO) plans to send miniaturised payloads aboard the Chandrayaan-II satellite, in line with the international standards, though the weight of the satellite is expected to be about double that of Chandrayaan-I. The second moon mission by India aims to have fewer scientific instruments than the ones on Chandrayaan-I spacecraft.
Chandrayaan-I spacecraft carried 11 scientific payloads (According to ISRO, there were 16 instruments as some payloads carried more than one instrument) including five from India with a total weight of about 100 kg. While the weight of the smallest instrument was about 150 gm, the bigger one weighed around 10 kg.
“As a spin-off of Chandrayaan-I, we will now work on miniaturising the payloads during Chandrayaan-II. For example, the IRS cameras used earlier during the first mission were bulky, and now we want to make it light. Space instruments are really getting lighter the world over, and we will follow the same path,” M Annadurai, project director of Chandrayaan mission said.
He said, the weight of the instruments were brought down considerably during Chandrayaan-I, and the plan was to bring it down further.
On the contrary, the weight of the satellite to be used during Chandrayaan-II mission is expected to be much higher than that used during the previous mission as the satellite will now have more propellant. The Chandrayaan-I spacecraft weighed 1,380 kg when it lifted off, including the 800 kg of propellant. While orbiting the moon, the weight of the satellite was about 550 kg.
“We expect Chandrayaan-II spacecraft to be nearly double the weight of the satellite used in the first mission and the propellant will also be almost double of that used in Chandrayaan-I,” Annadurai added.
In response to ISRO’s 'announcement of opportunities’ for Chandrayaan-I mission, space agencies from other countries had offered to send 26 instruments. Of this, six were selected after a rigorous evaluation process.
Following the success of Chandrayaan-I, especially after the discovery of water on lunar surface, ISRO is now getting much more proposals for carrying scientific payloads. “However, we can’t afford to carry so many payloads this time since the approach of the mission will be different now. We would try to carry more Indian payloads,” said Annadurai.