ISRO launched 36 satellites in its heaviest rocket from Satish Dhawan Space Centre in Sriharikota

Bangalore: The Launch Vehicle Mark 3 (LVM3) is ISRO’s newest medium-heavy lift launch vehicle, the heaviest rocket currently in use by the space agency. Formerly called the Geosynchronous Satellite Launch Vehicle Mark-III (GSLV MK-III), the rocket is designed to mainly launch satellites into geostationary orbit at 35,000km.

On Sunday, in its first commercial mission, the LVM-3 launched 36 satellites belonging to OneWeb’s constellation in five staggered phases into their designated orbits. The launch was facilitated through ISRO’s commercial arm, NewSpace India Limited (NSIL), and came about after Russia denied launch services because of Western sanctions.

At 6 tons, this was the heaviest payload carried by an Indian launch vehicle. At 0142 hrs IST, ISRO announced that the mission was a success.

With the successful complex insertion sequence, after years of test flights and hiccups and a national lunar mission in its pocket, India’s largest and heaviest rocket is now in the market to ferry international customer satellites into space.

The development for the GSLV MK-III began in the early 2000s, along with the development of the cryogenic upper stage, which ISRO has been trying to develop to reduce reliance on the currently-used Russian design. The failure of the upper stage to ignite in consecutive flights in the GSLV MK-II led to the first test flight of GSLV MK-III being delayed.

The rocket’s first experimental flight (also known as developmental or test flight) was initially scheduled for the early 2010s, but was pushed to make time for the Mars Orbiter Mission which launched in 2013.

The static fire tests for the rocket and its boosters were conducted in 2010, 2011, and 2015. The human-rated variant of the rocket, which is being developed for the Gaganyaan program, also underwent static fire tests this year.

The cryogenic upper stage was also tested successfully in 2017.

The maiden suborbital test flight of the GSLV MK-III was on 18 December 2014 as a test flight with a dummy upper stage. It carried the Crew Module Atmospheric Re-entry Experiment (CARE), a part of the Gaganyaan mission. The first orbital test flight occurred on 5 June 2017, carrying the GSAT-19 and placing it successfully in a 170km orbit. The second orbital test flight on 14 November 2018 placed the GSAT-29 into a geostationary orbit.

The first operational flight of the launch vehicle was on 22 July 2019, with Chandrayaan 2. The 4 tonne payload of this mission was, at the time, the heaviest payload carried by ISRO to orbit.

This Sunday’s successful mission carried a payload of 5,796kg — now ISRO’s heaviest till date.