He spent 13 years at ISRO working on the cryogenic engines behind Chandrayaan and Gaganyaan. Then he left to build the one engine ISRO had never attempted, and that only one company on Earth has ever flown. His name is Devakumar Thammisetty. After more than a decade inside India's space programme, he went to EPFL in Switzerland to study a single question: how do you make a rocket engine that can fly again and again? The answer he came back with is called full-flow staged combustion. It burns methane with liquid oxygen and routes every drop of both propellants through the turbines before they reach the chamber, which makes the engine more efficient, gentler on its own components, and far better suited to being reused. It is also brutally difficult. Only a handful of these engines have ever been tested anywhere in the world. Only SpaceX's Raptor has flown one. Astrobase calls it the hardest rocket engine cycle ever built. The man funding it made his money somewhere unexpected. Neeraj Khandelwal is an IIT Bombay graduate who spent the last decade co-founding CoinDCX and scaling it past 15 million users and a $2.1 billion valuation. He is Astrobase's primary investor. "Building India's first FFSC rocket engine means building the factory that can build the engine," he has said. "No shortcuts." They founded Astrobase in Bengaluru in 2024, along with two more former ISRO scientists, Pawan Kumar and Prashant M. A sub-scale engine hot fire in September 2025. High-speed turbopump tests in January 2026. The full engine design and manufacturing milestone in August 2026. A 21.5-acre propulsion test facility in Anantapur. In June 2026, IN-SPACe chose them from 43 applicants for its Technology Adoption Fund. SpaceX and Blue Origin each spent billions and most of a decade getting their staged combustion engines to work. Astrobase has raised around $10 million. The full engine hot fire is next. Four countries have ever tested an engine like this and India is not one of them yet.