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ISRO to launch heaviest rocket 36 satellites, countdown begins

Generally, GSLV rocket is used to launch India's geostationary communication satellites and hence it was named Geosynchronous Satellite Launch Vehicle (GSLV).

New Delhi: The Indian Space Agency (ISRO) on Saturday began a 24-hour countdown for the launch of its heavy-lift rocket GSLV Mk-3 at 12.07 pm. Its name has been changed to LVM3 M2. It has 36 'OneWeb' satellites. The 43.5-metre tall and weighing 644-tonne LVM 3 M2 rocket is scheduled to be launched on Sunday at 12.07 pm from the first second pad of India's Rocket Port in Sriharikota, Andhra Pradesh.

The fuel for the rocket will also be filled

"The countdown is going on smoothly. L110 stage gas charging and propellant filling is in progress," an Indian Space Research Organization (ISRO) official said. The rocket and satellite systems will be checked during the countdown. Fuel for the rocket will also be filled. The GSLV rocket is generally used to launch India's geostationary communication satellites and hence the name Geosynchronous Satellite Launch Vehicle (GSLV). GSLV Mk-3 refers to the third-generation rocket.

Will connect 36 small broadband communication satellites

The rocket, which took off on Sunday morning, will orbit the OneWeb satellites in Low Earth Orbit (LEO). ISRO has changed the name of GSLV Mk-3 to Mk-3 (Launch Vehicle Mk-3). The rocket will connect 36 small broadband communications satellites of Network Access Associated Limited (OneWeb) to LEO just 19 minutes into its flight.

LVM3 M2 three-stage rocket

OneWeb, Bharat is a joint venture between Bharti Global and the UK Government. The satellite company is planning to build a cluster of around 650 satellites in Earth Orbit (LEO) to offer communication services. The LVM3 M2 is a three-stage rocket, with the first stage fueled by liquid fuel on two strap motors powered by solid fuel, the second by liquid fuel and the third by a cryogenic engine.

ISRO's heavy-lift rocket has a capacity of 10 tonnes to LEO and four tonnes to Geo Transfer Orbit (GTO). "The OneWeb satellites will have a total launch mass of 5,796 kg," ISRO said. The 36 satellites will be on a dispenser system built by Swiss-based Beyond Gravity, formerly RUAG Space. Beyond Gravity previously provided satellite dispensers for the launch of 428 OneWeb satellites into Arianespace.

"The dispenser was supplied with 36 satellites by the vendor. It was used in all their earlier launches," the official said. This is the first time for Beyond Gravity that their dispenser has been fitted on an Indian rocket. Starting in 1999, ISRO has so far put 345 foreign satellites into orbit. With the successful launch of 36 OneWeb satellites, this number will increase to 381.

Plans to put another set into orbit in 2023

Another set of 36 satellites from OneWeb is planned to be put into orbit in January 2023. The launch brings OneWeb's cluster to 462 satellites, more than 70 per cent of the satellites required for OneWeb to reach global coverage. According to ISRO, the OneWeb constellation operates in an LEO polar orbit.

The satellites are arranged in 12 rings (orbital planes) with 49 satellites in each plane. The inclination of the orbital planes is near the polar (87.9°) and 1,200 km above Earth. Each satellite makes one complete revolution of the Earth every 109 minutes. The Earth is rotating beneath the satellites, so they will always be flying to new places on the ground. There will be 648 satellites in this constellation.

ISRO's commercial arm, NewSpace India Limited (NSIL), has signed two contracts with Network Access Associated Limited (OneWeb), the latter to place broadband communication satellites into Earth orbit. OneWeb's board voted to suspend satellite launches from the Baikonur rocket port in Russia.

For the first time, an Indian rocket will carry a payload of about six tonnes.

Meanwhile, the Sunday rocket mission has several firsts for the Indian space sector. This is the first commercial launch of GSLV Mk-3 and for the first time, an Indian rocket will carry a payload of around six tonnes. Similarly, OneWeb is using an Indian rocket to put its satellites into orbit for the first time. Also, this is the first commercial launch of GSLV Mk-3 contracted by NSIL, and the first time the renamed GSLV Mk-3 is being used to place satellites in LEO.


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