Indian Startup Othisis Test-Fires 3D-Printed Methalox Engine for Reusable Rocket Programme

Bengaluru-based space startup Othisis has successfully hot-fired a 5-kilonewton cryogenic rocket engine powered by liquid oxygen and methane, marking a significant propulsion milestone in the company’s effort to develop a fully reusable Indian launch vehicle.

The engine delivered a reported 5 kN of thrust and a total impulse of 100 kN·s during the successful test. Othisis says it designed and built the propulsion system for its reusable launch-vehicle programme and plans to place the engine aboard a vehicle demonstrator later in 2026. The achievement remains a ground-based hot-fire test rather than a flight demonstration, but it moves the startup closer to testing reusable rocket operations.

A major feature of the engine is its extensive use of additive manufacturing. Othisis describes the propulsion unit as fully 3D-printed, while company material specifically identifies an SLM-printed combustion chamber. Selective Laser Melting uses a high-powered laser to fuse successive layers of metal powder, allowing engineers to manufacture intricate internal structures that would be difficult to produce using conventional machining.

For rocket engines, additive manufacturing can simplify components such as combustion chambers and cooling passages while reducing the number of separately manufactured parts. Othisis has also developed its injector and other elements of the propulsion system in-house, reflecting an effort to control a larger part of the engine-development process within India.

The propulsion system uses liquid oxygen and methane, commonly known as methalox. Because both propellants must remain at extremely low temperatures, Othisis describes the engine as fully cryogenic. Methane has become increasingly attractive for reusable launch systems because it burns relatively cleanly and produces less carbonaceous residue than hydrocarbon fuels such as kerosene, potentially reducing maintenance requirements between flights.

Othisis has incorporated regenerative cooling into the design. In such an engine, cryogenic propellant circulates through passages around the combustion chamber before entering the combustion process, absorbing heat that would otherwise damage the chamber walls. The startup has also reported using a modular pintle-injector architecture intended to make the basic engine platform adaptable to different thrust requirements.

The successful firing followed an intensive development campaign. Reporting based on the company’s programme indicates that the team conducted more than 20 flow and test cycles, including unsuccessful ignition attempts, while simultaneously building much of its test infrastructure and control electronics. Othisis says the team developed the facility, propulsion hardware, electronics and firmware with a comparatively small engineering group.

The company had earlier reported a cryogenic regenerative and film-cooled engine test producing approximately 4.5 kN of thrust. The newer milestone increased the demonstrated thrust to 5 kN and reached the company’s stated 100 kN·s total impulse target.

Othisis ultimately wants to build fully reusable vertical-takeoff-and-landing rockets capable of returning propulsively after flight. Its own corporate material describes the company’s objective as building reusable rockets, while recent company updates identify the newly tested engine as intended for its reusable launch-vehicle programme and an upcoming demonstrator.

The distinction between the present achievement and the eventual goal is important. Othisis has successfully demonstrated an engine on the ground, but it has not yet demonstrated an orbital reusable rocket or a successful vertical landing. Flight testing will represent a much more demanding stage, requiring the propulsion system to work alongside flight computers, guidance software, structures, tanks and landing-control systems.

Nevertheless, the combination of methane propulsion, additive manufacturing and planned reusability places the programme within several technologies that IN-SPACe itself identifies as important for India’s future space sector. India’s long-term technology roadmap includes LOX-methane propulsion and recoverable or reusable launch vehicles among areas expected to shape the country’s private space ecosystem.

Othisis traces its origins to a rocketry community established in 2023 before the company formally incorporated in 2024. The startup says its long-term objective is to reduce launch costs by developing rockets that can return to Earth and fly repeatedly rather than discarding major vehicle elements after every mission.

The 5-kN engine remains a relatively small propulsion system compared with the engines required for large orbital launch vehicles, but that does not diminish its usefulness as a technology demonstrator. Smaller engines can allow startups to validate combustion stability, cryogenic plumbing, cooling systems, control electronics and reusable-flight concepts before scaling towards more powerful hardware.

For India’s private space industry, the Othisis test adds another indigenous propulsion programme to an increasingly diverse ecosystem. If the company successfully progresses from static firing to powered flight and eventually controlled vertical landing, its 3D-printed methalox engine could become the foundation for a new Indian approach to low-cost reusable access to space.