ISRO Achieves 175‑Tonne Semi‑Cryogenic Engine Hot Test, Paving Path to 200‑Tonne Thrust for LVM3 Upgrade

ISRO has achieved a major milestone by successfully conducting a hot test of its Semi‑Cryogenic Engine Power Head Test Article (PHTA) at 175‑tonne thrust on June 24, 2026, at the ISRO Propulsion Complex, Mahendragiri, Tamil Nadu. This test marks a crucial step toward full‑scale 200‑tonne thrust capability, strengthening India’s indigenous launch vehicle technology.

Notably, the Semi‑cryogenic engines use liquid oxygen (LOX) and isrosene (purified kerosene), which are cleaner and more efficient than older toxic fuels.

A full‑scale 200‑tonne thrust rocket engine means the engine can push with a force equal to lifting about 200 tonnes (200,000 kilograms) straight off the ground — imagine the weight of 130 cars being lifted at once. It’s the raw “push power” that propels a massive rocket skyward.

A 200‑tonne thrust class engine puts ISRO in the league of agencies like NASA and Roscosmos, which use similar high‑power engines for heavy‑lift missions.

ISRO Achieves 175‑Tonne Semi‑Cryogenic Engine Hot Test

Key Highlights of the Test

• Date & Location: June 24, 2026, at ISRO Propulsion Complex (IPRC), Mahendragiri, Tamil Nadu
• Thrust Level: Achieved 175 tonnes (88%) thrust, up from earlier tests at 94 tonnes (47%) and 120 tonnes (60%)
• Engine Systems: PHTA includes all engine subsystems except the thrust chamber
• Performance: Demonstrated successful operation of main turbopumps delivering 400 and 500 bar outlet pressures
• Outcome: All parameters matched predictions, providing confidence for the upcoming 200‑tonne (100%) thrust test

Strategic Importance

• Indigenous Development: Strengthens India’s self‑reliance in advanced propulsion systems
• SC120 Stage: Powered by the 2000 kN‑class SE2000 engine, will replace the current L110 core stage of the LVM3 launch vehicle
• Payload Boost: Expected to substantially increase payload capacity and enhance operational efficiency
• Cleaner Propellants: Uses Liquid Oxygen (LOX) and purified kerosene (isrosene), which are non‑toxic and more efficient

Roadmap for LVM3

• Integration Plan: Semi‑cryogenic propulsion will be paired with an uprated cryogenic upper stage
• Capability Expansion: Enhances LVM3’s payload capacity for heavier satellites and deep‑space missions
• Global Competitiveness: Positions ISRO alongside leading space agencies using semi‑cryogenic systems

Technical Milestones Achieved

Test Phase	Thrust Level	Key Achievements
Initial Tests	94 Tonne (47%)	Validated ignition build‑up
Mid‑Stage Tests	120 Tonne (60%)	Stable operation at higher thrust
Latest Test	175 Tonne (88%)	Turbopumps at 400–500 bar, steady state
Next Target	200 Tonne (100%)	Full engine demonstration

Broader Impact

• National Security & Economy: Enhances India’s ability to launch heavier payloads for defense, communication, and commercial satellites
• Sustainability: Cleaner fuels reduce environmental risks compared to hypergolic propellants
• Global Market: Strengthens India’s competitiveness in the international satellite launch market

This achievement is a critical step in ISRO’s roadmap toward advanced propulsion systems and expanded launch capabilities.

India Opens Heavy‑Lift Rocket LVM3 to Private Sector for First Time

IN-SPACe has officially opened an Expression of Interest (EOI) for the transfer of ISRO’s heavy-lift rocket LVM3 (“Baahubali”) to private Indian companies, marking a historic step in India’s space sector liberalisation. The selected entity will gain full technology transfer, with ISRO handholding for up to 42 months or until two successful launches.

With this EOI, IN-SPACe opens India’s largest rocket for private contracts, including global satellite launches.

Moreover, it also marks the first time India’s heavy-lift rocket is being offered for private sector end-to-end realisation.

This development follows the PSLV transfer last month, signalling India’s move to let private industry handle operational Launches while ISRO to focus on advanced R&D, Gaganyaan, and interplanetary missions.

Key Highlights of the LVM3 EOI

• Technology Transfer: End-to-end realisation, operation, manufacturing, and commercialisation of LVM3.
• ISRO Support: Infrastructure access, mentorship, and engineering guidance for 42 months or until two launches.
• Eligibility Criteria:
  • Minimum 7+ years operational history
  • 5+ years in space/aerospace experience
  • Financial strength: ₹800 Cr+ average turnover OR ₹2000 Cr+ valuation
• Deadline: June 29, 2026
• Payload Capability: 4,000 kg to GTO and 8,000 kg to LEO
• Strategic Context: Follows PSLV transfer last month; frees ISRO to focus on advanced R&D, Gaganyaan, and interplanetary missions.

Why This Matters

Factor	Impact
Private Sector Role	Moves Indian firms from component suppliers to full-fledged launch service operators.
Global Space Economy	Positions India to scale launch frequencies and compete with SpaceX, Arianespace, etc.
Domestic Capability	Reduces reliance on ISRO for operational launches; strengthens sovereign manufacturing.
Commercialisation	Opens India’s heaviest rocket for private contracts, including satellite launches for global clients.

Risks & Challenges

• Late Entry: Industry experts note India is entering private heavy-lift commercialisation later than global peers.
• Absorption Complexity: LVM3 is a complex system; private firms must quickly build expertise.
• Capital Intensive: High investment required; only large aerospace players or consortia may qualify.
• Global Competition: Competing against established launch providers with proven track records.

Context for India

• LVM3 Missions: Chandrayaan-2, Chandrayaan-3, and Gaganyaan test flights.
• Strategic Goal: Scale India’s launch frequency and reduce bottlenecks at ISRO.
• Private Sector Push: Comes after PSLV transfer, signalling a broader shift to industry-led operations.

Eutelsat OneWeb Eyeing ISRO to Boost Worldwide Satellite Coverage

Eutelsat OneWeb is planning to use ISRO’s heavy-lift rockets (LVM3) for part of its second-generation (Gen-2) satellite constellation, aiming to deploy over 340 new low-earth orbit (LEO) satellites by 2027 to expand global coverage and resilience said a report by Business Today.

In October this year, Eutelsat Group issued a regulatory news release confirming successful launches and outlining future plans, including reliance on ISRO’s LVM3 for upcoming missions.

OneWeb began launches in 2019 and now operates ~640 satellites in orbit, forming a near-global broadband network. The original plan was for 648 satellites, manufactured by Airbus Defence and Space. The network is fully operational, but about 100 satellites from the initial fleet are due for replenishment in the coming years. Eutelsat OneWeb is preparing to deploy 340+ new satellites by 2027, creating a more advanced and flexible architecture.  

Key Highlights

• Gen-2 Expansion: Eutelsat OneWeb already operates ~640 satellites in orbit (Gen-1). The Gen-2 rollout will add 340+ satellites, enhancing flexibility, capacity, and resilience.
• ISRO Partnership: India’s LVM3 rocket, nicknamed Bahubali, is being considered for these launches. ISRO has proven reliability with commercial missions, including recent deals with AST SpaceMobile.
• Strategic Goals: The Gen-2 fleet will strengthen business-to-business (B2B) and business-to-government (B2G) offerings, targeting enterprise connectivity, defense, and sovereign data needs.
• Replenishment Needs: About 100 Gen-1 satellites are due for replacement, making ISRO’s role in upcoming launches even more critical.

Comparison: ISRO vs Other Launch Partners

Criteria	ISRO (LVM3)	SpaceX (Falcon 9)	Arianespace (Ariane 6)
Reliability	100% success rate for LVM3 commercial launches	High success rate, frequent launches	New vehicle, still proving track record
Payload Capacity	~6.5 tons to LEO	~22 tons to LEO	~20 tons to LEO
Cost Efficiency	Competitive pricing, attractive for bulk launches	Higher costs but frequent cadence	Traditionally higher costs
Geopolitical Advantage	Strong India-Europe ties, diversification from US	US-based, subject to export controls	EU-based, aligned with Eutelsat HQ
Recent Deals	AST SpaceMobile BlueBird satellite launch	Starlink competitor, less likely to host OneWeb	Preparing for commercial debut

Risks & Considerations

• Launch Cadence: ISRO’s LVM3 has fewer annual launches compared to SpaceX, which could affect timelines.
• Competition: SpaceX’s Starlink is a direct competitor, making reliance on Falcon 9 less strategic for OneWeb.
• Technology Transition: Gen-2 satellites will use a more advanced architecture, requiring careful integration with ISRO’s launch systems.
• Regulatory Factors: India’s satcom policies and spectrum allocation will influence how quickly OneWeb can expand services locally.

Strategic Impact

• India’s Role: Partnering with ISRO positions India as a major player in global satcom, aligning with its ambitions in sovereign data and space commercialization.
• Global Coverage: Gen-2 satellites will improve OneWeb’s reach in underserved regions, supporting enterprise, government, and defense connectivity.
• Market Differentiation: By diversifying launch providers, OneWeb reduces dependency on SpaceX and strengthens resilience against geopolitical risks.

ISRO’s Giant Leap: Heaviest Communication Satellite CMS-03 Successfully Launched

ISRO successfully launched its heaviest communication satellite, CMS-03 (also known as GSAT-7R), aboard the LVM3-M5 rocket on November 2, 2025, from Sriharikota. The 4,410 kg satellite is designed to provide secure, high-bandwidth, multi-band communication for the Indian Armed Forces, especially the Navy, marking a major milestone in India’s heavy-lift space capabilities.

Kudos Team #ISRO!

India’s #Bahubali scales the skies, with the successful launch of #LVM3M5 Mission!

“Bahubali” as it is being popularly referred, LVM3-M5 rocket is carrying the CMS-03 communication satellite, the heaviest ever to be launched from the Indian soil into a… pic.twitter.com/ccyIPUxpIX

— Dr Jitendra Singh (@DrJitendraSingh) November 2, 2025

Key Highlights of the CMS-03 Mission

• Launch Vehicle: LVM3-M5 (Bahubali), India’s most powerful rocket
• Launch Site: Satish Dhawan Space Centre (SDSC), Sriharikota
• Date & Time: November 2, 2025, at 17:26 IST
• Satellite Mass: ~4,410 kg — heaviest communication satellite launched from Indian soil
• Orbit: Geosynchronous Transfer Orbit (GTO), ~29,970 km x 170 km
• Mission Purpose: Replace GSAT-7 (2013) and enhance secure naval and defense communications

We got the look of #CMS03 🛰️ #ISRO pic.twitter.com/UMIxyO8q7U

— ASTROSPACE (@Arslanshaikh_) November 2, 2025

Strategic Importance

• Defense Communications: Tailored for the Indian Navy, ensuring encrypted, high-capacity links
• Indigenous Capability: Fully developed in India, reinforcing strategic autonomy
• Heavy-Lift Milestone: First >4,000 kg satellite launched into GTO from Indian soil
• Continuity & Upgrade: Replaces GSAT-7 with greater bandwidth and wider coverage

Comparative Context

Mission	Rocket	Payload Mass	Orbit	Purpose
CMS-03 (2025)	LVM3-M5	4,410 kg	GTO	Secure defense communications
GSAT-7 (2013)	Ariane-5	2,625 kg	GTO	Naval communications
Chandrayaan-3 (2023)	LVM3-M4	3,900 kg	Lunar Transfer	Lunar exploration

Broader Implications

• For India’s Space Program: Strengthens ISRO’s credibility in the global heavy-lift launch market
• For National Security: Enhances maritime domain awareness and secure communication
• For Future Missions: Validates LVM3’s readiness for heavier payloads, including crewed missions

ISRO's Next Milestone: LVM3-M5 Prepares to Launch High-Tech BlueBird Satellite

The Cryogenic Upper Stage (C25) of ISRO's LVM3 launch vehicle was recently flagged off from the ISRO Propulsion Complex (IPRC) in Mahendragiri, Tamil Nadu, to the launch complex at Sriharikota. This marks a significant step for the fifth operational mission of LVM3 (LVM3-M5), which is set to launch the advanced American communications satellite, BlueBird Block-2.

This stage, powered by the indigenous CE20 cryogenic engine, has a propellant capacity of 28.5 tonnes and was developed by the Liquid Propulsion Systems Centre (LPSC). The upcoming mission is part of a commercial agreement between New Space India Limited (NSIL) and AST & Science, LLC.

The BlueBird satellite, weighing approximately 6,000 kg, will operate in Low Earth Orbit and is designed to enable direct satellite-to-smartphone communication, a groundbreaking technological advancement.

It's an important milestone for ISRO, showcasing India's growing role in global space commerce.

BlueBird Block 2 satellite

A computer rendering of AST SpaceMobile's five first-generation, Block 1 BlueBird commercial satellites in low Earth orbit. The spacecraft are designed to provide the first-ever space-based cellular broadband service to unmodified mobile phones. Five of the satellites launched on September 12, 2024 and unfolded throughout October 2024. [ IMAGE - ast-science.com] 

The BlueBird Block 2 satellite is developed by Texas, US -based AST SpaceMobile, which has collaborated with ISRO for the launch of its BlueBird Block-2 satellites using the LVM3 rocket. This partnership underscores India's growing role in global space commerce.

The satellite represents a significant leap in space-based cellular broadband technology. These satellites are designed to provide direct-to-smartphone connectivity without the need for ground-based infrastructure. Each satellite features expansive communication arrays, measuring up to 2,400 square feet, making them the largest commercial communication arrays ever deployed in Low Earth Orbit (LEO).

The Block 2 satellites are capable of delivering data speeds of up to 120 Mbps, supporting high-demand applications like HD video streaming and real-time data sharing. This technology aims to bridge connectivity gaps, especially in remote and underserved areas, by creating a global space-based cellular network.

Notably, AST SpaceMobile has established a research and development hub in Hyderabad, focusing on next-generation hardware, software, and space-related technologies. This facility is expected to drive innovation and strengthen AST SpaceMobile's technological capabilities.