BENGALURU: The Indian Space Research Organisation (ISRO) on Wednesday launched the heaviest satellite so far after its Launch Vehicle Mark-3 (LVM3)-M6 rocket lifted off with the 6.10-tonne BlueBird-6 Block-2 communication satellite of US-based AST SpaceMobile (AST and Science, LLC) and released it accurately in a in the 518.50 km altitude circular Low Earth Orbit (LEO).
The launch took place at 8.55 am and the satellite released in its orbit at 9.11 am in what ISRO scientists described as a “textbook launch”.
The heaviest satellite that ISRO has launched so far was the 4.40-tonne Communication Satellite 03 – also known as GSAT-7R – in a Geosynchronous Transfer Orbit (GTO) on November 2, 2025 to provide the Indian Navy with secure, advanced multi-band maritime communication for ships, submarines and aircraft across the Indian Ocean Region. It replaced the older GSAT-7 (Rukmini) satellite.
The LVM3-M6/BlueBird Block-2 Mission was executed from the second launch pad of the Satish Dhawan Space Centre (SDSC) in Sriharikota. The launch was a commercial deal between ISRO’s business arm NewSpace India Ltd (NSIL) and US-based AST SpaceMobile (AST and Science, LLC)
ISRO Chairman V Narayanan said this was the third commercial launch undertaken by ISRO using the LVM3 launcher and the first dedicated to a foreign customer for communication purposes. It was also the ninth launch mission of the LVM3 rocket – nicknamed “Bahubali” – all of which have been successful.
LVM3-M4 carried India’s historic Chandrayaan-3 lunar mission in July 2023, which recorded the country’s first successful touchdown of the unmanned lunar spacecraft on August 23, 2023 – a feat which also recorded India as the first among nations to have landed near the lunar South Pole.
The LVM3-M6, also known as the Geosynchronous Satellite Launch Vehicle (GSLV)-MkIII, is a three-stage rocket with a cryogenic engine designed and developed by ISRO’s Liquid Propulsion Systems Centre. It uses two S200 solid rocket boosters to provide enormous thrust required for the lift-off with heavier payloads.
Satellite will provide faster 4G and 5G services: ISRO
The booster has been developed by Vikram Sarabhai Space Centre. The Texas-based AST SpaceMobile is building the first and only space-based cellular broadband network, accessible directly by smartphones and designed for both commercial and government applications.
Explaining the BlueBird Block-2 Mission, the team said the satellite – which will be a part of a constellation of other similar satellites under the mission – will provide faster 4G and 5G services and video calls. It also aims at enhancing network connectivity with locations where there were hassles earlier. AST SpaceMobile has launched five satellites, Bluebird 1-5 in September 2024, which provide continuous coverage across the US and other select countries.
The LVM3-M6 has injected the satellite in the 518.50 km circular LEO orbit at a 53 degree inclination to the equator. It is just 1.5 km lower than the designated orbit, and is considered accurate. This precise placement is also an achievement marked by the ISRO team, said Narayanan.
Senior scientists said the satellite was brought to Sriharikotta on October 16. The launch was postponed due to technical issues before it was decided to finally launch it on December 24. The satellite and its data are being tracked by ISRO’s space stations in Sriharikota and Port Blair. It will also be tracked by satellite data centres in Australia and Indonesia.
The story is reported by Bosky Khanna of The New Indian Express
