News

All systems go for India's lunar voyage

Vanita Srivastava

doi:10.1038/nindia.2019.87 Published online 12 July 2019

[Update on 15 July 2019: ISRO called off the launch of Chandrayaan-2 just 56 minutes before its scheduled launch due to a technical snag in the launch vehicle system.

Update on 18 July 2019: ISRO announced the new launch date as 22 July 2019.]

The launch vehicle carrying Chandrayaan-2 on its way to the launch pad.

© ISRO

India is set to embark on its second lunar voyage with a mission to the Moon’s south pole. Chandrayaan-2 will be launched on its 384,400 km voyage from the Satish Dhawan Space Center in Sriharikota, by GSLV Mk-III, India’s most powerful launcher to date.

Leading the project are two senior female scientists, project director Vanitha Muthayya and mission director Ritu Karidhal.

“Chandrayaan-2 is a programme for the entire nation,” said Indian Space Research Organisation (ISRO) chief, K Sivan.

Chandrayaan-2 has several science payloads to expand the lunar scientific knowledge through detailed study of topography, seismography, mineral identification and distribution and surface chemical composition.

According to ISRO, the Rs 1000 crore mission seeks a better understanding of the origin and the evolution of the Moon. Its polar regions are intriguing to scientists for their abundant water ice, on the floors of permanently shadowed craters. Such ‘lunar cold traps’ contain a fossil record of the early solar system and also harbour a precious resource that could aid human exploration of Earth's nearest neighbour.

The configuration

Improving on its predecessor Chandrayaan-1, launched in October 2008, Chandrayaan-2 is armed with three modules — orbiter, lander and rover, and almost all the components are designed and fabricated in India.

The orbiter which weighs 2.4 tonnes, has a mission life of one year   and will operate in a 100x100 km lunar polar orbit.

The 1.4 tonnes lander, Vikram, to be placed on the orbiter is named after Dr Vikram Sarabhai, the father of the Indian space programme. The 27 kg rover inside the lander is a six -wheeled robotic vehicle, Pragyan, ‘wisdom’ in Sanskrit.

Orbit trajectory

Chandrayaan-2 will be ejected into an Earth parking orbit, before a series of manoeuvres raises its orbit to a Lunar Transfer Trajectory. On entering the Moon’s sphere of influence, the on-board thrusters will slow down the spacecraft for a lunar capture.

The lander will separate from the orbiter and the rover will roll out and carry the experiments on lunar surface for one lunar day, which is equivalent to 14 Earth days.

The spacecraft will soft land the lander in a high plain between two craters – Manzinus C and Simpelius N at a latitude of about 70 degrees south. Soft landing, which India is attempting for the first time, aims to prevent damage or destruction of the vehicle.

“The 15-minute operation, when Vikram makes its final descent and soft-lands, will be the most terrifying moments as we have never undertaken such a complex mission,” said Sivan.