🗞️ Why in News Bengaluru-based Astrobase Space Technologies unveiled EVEREST on August 7, 2026, an 80-tonne-class, 800 kN, liquid oxygen and liquid methane rocket engine built on the Full-Flow Staged Combustion cycle. If flight-proven, India would become only the fourth country to test an FFSC engine, after the erstwhile Soviet Union, the United States and China.
What a Rocket Engine Cycle Is
A liquid rocket engine burns fuel and oxidiser together, but before that combustion happens, both propellants must be pressurised and delivered to the main combustion chamber by turbopumps. The cycle describes how the engine powers those turbopumps, and it is one of the most consequential design choices in the entire vehicle, because it determines efficiency, complexity, cost and how many times the engine can be reused before it wears out.
The Ladder of Difficulty
| Cycle | How it works | Where it sits |
|---|---|---|
| Gas generator | A small separate combustion reaction powers the turbopumps; its exhaust is dumped overboard, unused | Simplest, least efficient; used by many operational engines including early Falcon 9 boosters |
| Staged combustion | Turbopump exhaust is fed back into the main chamber and burned, recovering the energy the gas-generator cycle wastes | More efficient, more complex; used by Russia’s RD-180 and India’s own Vikas engine in a related form |
| Full-flow staged combustion (FFSC) | Both the fuel and the oxidiser are fully gasified in separate preburners before reaching the main chamber; every drop of propellant passes through a turbopump | Hardest to build, most efficient, longest engine life |
FFSC is difficult because it requires two preburners running at different, extreme conditions, an oxidiser-rich one and a fuel-rich one, each demanding materials that resist their respective environment without corroding or failing. The payoff is that both turbopumps operate at lower temperature and pressure than in a conventional staged-combustion engine, which is what allows an FFSC engine to be reused many times without the wear that limits other cycles. This is the same cycle used in SpaceX’s Raptor, the engine powering Starship.
Why the Propellant Choice Matters Too
EVEREST uses liquid oxygen and liquid methane (LOX/LCH4), not the kerosene or hydrazine derivatives more common in older Indian propulsion. Methane burns cleaner than kerosene, leaving less residue that would otherwise force more frequent inspection and refurbishment between flights, which matters directly for a reusable vehicle. Methane is also, in principle, produceable from carbon dioxide and water through the Sabatier reaction, which is why it has become the propellant of choice for designs that look toward eventual Mars missions, though that is a longer-horizon consideration than anything relevant to Astrobase’s near-term plans.
Why a Private Company Attempting FFSC Is the Actual News
Every national space programme that has built an FFSC engine did so as a state programme with decades of institutional propulsion experience behind it: the Soviet Union’s RD-270 development in the 1960s, and more recent Chinese and American efforts. A private company with no equivalent institutional back-catalogue choosing to attempt the hardest cycle, rather than the gas-generator or conventional staged-combustion cycles that would have been faster and cheaper to develop, is a statement about ambition and about the maturity that India’s private space ecosystem now believes it has reached following the sector’s opening after 2020.
Astrobase completed sub-scale hot-fire tests in 2025 and high-speed turbopump trials in early 2026, and targets a full-engine hot-fire test later in 2026, with a maiden vehicle launch targeted for December 2028. Production capacity is planned at up to 50 engines a year, which signals an intent to build a reusable, medium-lift launch vehicle around the engine rather than a one-off demonstration.
UPSC Relevance
GS Paper 3: Science and technology, developments and their applications; indigenisation of technology and developing new technology; achievements of Indians in science and technology; private participation in the space sector.
Prelims focus: The distinction between gas generator, staged combustion and full-flow staged combustion cycles; LOX/LCH4 as a propellant combination and its reusability rationale; the three prior countries with FFSC test capability; the Indian Space Policy 2023 and IN-SPACe as the enabling framework for private space activity.
Mains angle: “The difficulty of a cycle a company chooses to attempt reveals more about institutional ambition than the thrust number it advertises.” Examine what Astrobase’s choice of the Full-Flow Staged Combustion cycle signals about the maturity of India’s private space sector, and discuss the policy framework that has enabled this entry.
📌 Facts Corner, Knowledgepedia
EVEREST Engine:
- Developer: Astrobase Space Technologies, Bengaluru; unveiled August 7, 2026
- Thrust class: 800 kN (80-tonne class)
- Propellants: liquid oxygen and liquid methane
- Cycle: Full-Flow Staged Combustion (FFSC)
- Prior countries with FFSC test capability: erstwhile USSR, USA, China
- Same cycle as SpaceX’s Raptor engine (Starship)
- Sub-scale hot-fire tests: 2025; turbopump trials: early 2026; full-engine hot-fire targeted later in 2026
- Targeted maiden launch: December 2028; planned production: up to 50 engines a year
Rocket Engine Cycles:
- Gas generator cycle: turbopump exhaust dumped overboard, unused; simplest, least efficient
- Staged combustion cycle: turbopump exhaust fed back into the main chamber; more efficient
- Full-flow staged combustion: both propellants fully gasified in separate preburners before the main chamber; hardest to build, most reusable
Other Relevant Facts:
- IN-SPACe (Indian National Space Promotion and Authorisation Centre), set up 2020, is the single-window authorising body for private space activity in India
- NSIL (NewSpace India Limited) is ISRO’s commercial arm, distinct from private start-ups like Astrobase
- Methane’s production route via the Sabatier reaction (from carbon dioxide and hydrogen) is why it is favoured for long-horizon Mars-mission propellant concepts
- India’s own Vikas engine, used on PSLV and GSLV, operates on a staged-combustion-derived cycle, not FFSC
Source: The Fourth Country: A Bengaluru Startup Builds India's First Full-Flow Staged Combustion Engine — Ujiyari.com | Free UPSC & State PCS Current Affairs
