Gaganyaan is expected to be launched on the back of ISRO's GSLV Mark III rocket

Highlights Gaganyaan is scheduled to launch by December 2021

The PM had announced the mission in his Independence Day speech last year

IAF and ISRO signed an agreement for crew selection and initial training

All eyes may have been on Chandrayaan 2 and lunar lander Vikram tonight as India looked to become only the fourth nation to successfully soft land on the moon's surface. However, behind the scenes ISRO and the Air Force are already busy planning for Gaganyaan, the nation's first manned space mission, with the IAF today announcing that the first level of selection of potential astronauts has been completed.

"Completed Level-1 of Indian Astronaut selection at Institute of Aerospace Medicine. Selected Test Pilots underwent extensive physical exercise tests, lab investigations, radiological tests, clinical tests and evaluation on various facets of psychology. #MissionGaganyaan," the Indian Air Force said on its official Twitter account.

#MissionGaganyaan -IAF completed Level-1 of Indian Astronaut selection at Institute of Aerospace Medicine. Selected Test Pilots underwent extensive physical exercise tests, lab investigations, radiological tests, clinical tests & evaluation on various facets of their psychology. pic.twitter.com/O3QYWJYlQd — Indian Air Force (@IAF_MCC) September 6, 2019

The Gaganyaan mission, which will consist of two unmanned flights in addition to the manned one, was announced by Prime Minister Narendra Modi during his Independence Day speech last year, is scheduled to launch by December 2021.

The mission entails placing a three-member crew into a low-Earth orbit for a period of seven days. If successful, it will make India the fourth country to independently send human beings into space.

In May this year, the Air Force and ISRO signed an agreement for crew selection and initial training.

The chosen astronauts - four in total - will then be sent to Russia by November for 15 months of training at the Yuri Gagarin Cosmonaut Training Centre, per the terms of a deal announced by Prime Minister Narendra Modi during his visit to that country earlier this week, for advanced training.

Gaganyaan astronauts will be called "Vyomnauts"; 'vyom' is a Sanskrit word that means 'space'.

The programme is expected to cost more than Rs 10,000 crore; this includes the cost of technology development, flight hardware realisation and essential infrastructure elements. The mission will consist of two unmanned flights in addition to the manned flight.

The manned mission is likely to be launched on the back of ISRO's GSLV Mark III rocket, which is the same one that launched Chandrayaan 2 from Sriharikota in Andhra Pradesh on July 22.

The GSLV Mark III - Geosynchronous Satellite Launch Vehicle - is India's most powerful rocket.