The Indian Space Research Organisation (ISRO) has recently propelled their heaviest rocket, the Launch Vehicle Mark 3 (LVM3 or GSLV Mark 3), into orbit with 36 satellites of UK-based OneWeb. OneWeb operates a global communications network maintained by a constellation of 648 Low Earth Orbit (LEO) satellites.
LVM3-M2: A Feat for ISRO
The LVM3-M2 mission signifies a dedicated commercial operation for OneWeb via NewSpace India Limited (NSIL), a Central Public Sector Enterprise (CPSE). This mission holds prominence as it is the first multi-satellite endeavour, carrying 36 OneWeb satellites to the LEO with the heaviest payload, weighing 5,796 kg till date by an LVM3.
Capabilities of LVM3
The LVM3 can launch 4,000-kilogram class satellites into Geosynchronous Transfer Orbit (GTO) and carry payloads up to 8,000 kgs to LEO. It comprises three stages, including two solid propellant S200 strap-ons on its sides, and a core stage encompassing an L110 liquid stage and a C25 cryogenic stage.
Firsts and Technical Achievements
This launch marks several firsts for NSIL and ISRO: the LVM3’s inaugural commercial mission and first launch to LEO, introduction of a rocket with a six-ton payload, and the first OneWeb mission with NSIL/Department of Space. Technical advancements include improved handling of multiple satellite separation events, longer nominal mission duration, and ensuring data availability for the entire mission duration. A new payload adaptor and interface ring for the satellites dispenser have also been realised.
OneWeb Constellation: An Overview
The OneWeb constellation operates in a LEO Polar Orbit, featuring 12 rings or orbital planes with 49 satellites in each plane. The planes are inclined near polar at 87.9 degrees and are situated 1,200 km above the Earth. Each satellite completes a full trip around the earth every 109 minutes, effectively covering new locations on the ground throughout its journey.
ISRO’s Success Story: A Glance at Other Launch Vehicles
ISRO began its journey with the Satellite Launch Vehicle (SLV) and was succeeded by the Augmented SLV (ASLV), both of which were capable of carrying small satellites to lower earth orbits. The Polar SLV (PSLV) emerged in the 1990s as ISRO’s primary rocket.
Present-day PSLV is significantly advanced and more potent compared to its earlier versions. It marked a milestone as India’s first launch vehicle equipped with liquid stages and has been the most reliable rocket used by ISRO, boasting 52 successful flights out of 54.
The Geosynchronous SLV (GSLV) was created for heavier payloads and deeper space explorations. In its 18 missions, GSLV has had four failures but now comes with an indigenously developed Cryogenic Upper Stage (CUS), making it self-sufficient for launching heavier satellites into space.
The GSLV Mark III, renamed as Launch Vehicle Mark III, is ISRO’s heaviest rocket so far. It was used for the Chandrayaan-2 moon mission in 2019 and is versatile enough to travel to Geostationary Orbit (GEO), Medium Earth Orbit (MEO), Low Earth Orbit (LEO), and even sun and moon missions.
