Why in news?

The Indian Space Research Organisation (ISRO) is set to launch the LVM-3 rocket carrying its heaviest-ever satellite, BlueBird Block-2 (≈6,100 kg).

The satellite will be placed into a low Earth orbit (LEO) of about 520 km roughly 15 minutes after liftoff.

BlueBird Block-2 will be the largest commercial communications satellite deployed in LEO to date. Designed by AST SpaceMobile, the satellite is part of a constellation aimed at direct-to-mobile connectivity.

Unlike traditional satellites that rely on ground stations, this system will communicate directly with standard smartphones, enabling 4G/5G voice and video calls, messaging, streaming, and data access globally.

What’s in Today’s Article?

• LVM3: India’s Heavy-Lift Launch Vehicle
• ISRO’s Push to Optimise LVM3 Engines
• Significance of LVM3-M6 Mission

LVM3: India’s Heavy-Lift Launch Vehicle

• The Launch Vehicle Mark-3 (LMV3) is a three-stage launch vehicle weighing about 640 tonnes and standing 43.5 metres tall.
• Developed over decades, it represents the peak of India’s launch vehicle engineering.
• S200 Solid Strap-On Boosters: Power at Lift-Off
  • The first stage comprises two S200 solid-propellant boosters, among the most powerful solid rockets in use worldwide.
  • They provide the massive thrust needed at lift-off to overcome gravity and pass through Earth’s dense lower atmosphere.
• L110 Liquid Core Stage: Controlled Acceleration
  • After booster separation, the L110 liquid stage takes over, using hypergolic propellants for smooth, controllable thrust.
  • This stage plays a crucial role in shaping the satellite’s trajectory and reflects India’s long-standing expertise in liquid propulsion.
• C25 Cryogenic Upper Stage: Precision and Efficiency
  • The C25 cryogenic stage burns supercooled liquid oxygen and hydrogen stored below –180°C.
  • It is India’s largest and most advanced cryogenic engine, offering high efficiency, longer burn duration, and precise orbit insertion—key to technological self-reliance achieved after decades of effort.

ISRO’s Push to Optimise LVM3 Engines

• ISRO is upgrading the LVM3 to meet human-rating requirements for Gaganyaan and to increase lift capacity for modules of the proposed Bharatiya Antariksh Station.
• This involves adding redundancies for safety and boosting overall performance.
• More Thrust from the Cryogenic Upper Stage
  • ISRO is enhancing the cryogenic upper stage, which provides nearly 50% of the velocity needed for geosynchronous missions.
  • The current C25 stage carries 28,000 kg of propellant and produces 20 tonnes of thrust.
  • The planned C32 stage will carry 32,000 kg of fuel, increasing thrust to 22 tonnes, enabling heavier payloads.
• Switch to a Semi-Cryogenic Second Stage
  • The agency is considering replacing the liquid-propellant second stage with a semi-cryogenic engine using refined kerosene and liquid oxygen.
  • This change would lower costs, improve efficiency, and raise LEO payload capacity from ~8,000 kg to ~10,000 kg, a configuration likely for space-station module launches.
• Bootstrap Reignition for Multi-Orbit Missions
  • To support missions deploying satellites into multiple orbits, ISRO is developing bootstrap reignition for cryogenic engines.
  • This allows the upper stage to restart without external gases (like helium), reducing system mass and increasing payload capability—especially valuable for LEO constellation missions.

Significance of LVM3-M6 Mission

• The LVM3-M6 / BlueBird Block-2 mission is a dedicated commercial launch using ISRO’s LVM3 rocket to deploy the BlueBird Block-2 communication satellite of AST SpaceMobile.
  • It represents the sixth operational flight of the LVM3 launch vehicle.
• This is ISRO’s third commercial mission with the LVM-3, after launching OneWeb satellites in 2022–23.
• With alternatives like SpaceX’s Falcon-9 and European Space Agency’s Ariane-6 available, the launch is a chance for ISRO to prove it can deliver heavy launches at lower cost.
• Expanding the LVM-3’s Role
  • Originally designed for geosynchronous missions (~36,000 km), the LVM-3 has now proven versatile in low Earth orbit (LEO) deployments.
  • This marks the third LEO mission for the vehicle, reflecting its evolution from the earlier GSLV-Mk3.
• Operational Readiness and Turnaround Time
  • The launch follows the CMS-03 mission on November 2, making it the shortest gap between two LVM-3 launches.
  • It tests ISRO’s ability to assemble and execute heavy missions rapidly, a key metric for commercial reliability.
• Record-Breaking Payload
  • At 6,100 kg, the BlueBird payload is ISRO’s heaviest satellite ever placed into orbit, surpassing the cumulative OneWeb payloads (~5,700 kg) to LEO and the 4,410 kg CMS-03 sent to geosynchronous transfer orbit last month.
• Strategic Momentum
  • This is the second year since 2023 that ISRO flies two LVM-3 missions in a single year, underscoring growing cadence, capability, and confidence in India’s heavy-lift launch ecosystem.