Skyroot's rocket has a stage that thinks. Here is how it aims for exact orbit
A rocket leaving Earth is mostly violence. The first three stages of Skyroot Aerospace's Vikram-1 are built for one job: raw thrust, the brute force
A rocket leaving Earth is mostly violence. The first three stages of Skyroot Aerospace's Vikram-1 are built for one job: raw thrust, the brute force needed to tear free of gravity. Then everything changes. At the very top sits a small, patient stage that does not push as much as it thinks. The Orbit Adjustment Module, the liquid-powered top stage of Skyroot Aerospace's Vikram-1, is built for precision rather than raw thrust. (Photo: Skyroot) Read Full Story Skyroot calls it the Orbit Adjustment Module, or OAM, and on Sunday, June 21, the Hyderabad company released a film explaining it. Reaching space is the easy part. Arriving at exactly the right address is the hard one. A satellite released even a few metres per second too fast sails past its orbit. Released too slow, it falls back and dies. The OAM exists so that neither happens. AN ENGINE THAT CAN STOP AND START AGAIN The lower stages of Vikram-1 burn solid fuel, rather like a firework.
Once lit, they cannot be paused or relit. The OAM does the opposite. It is powered by a liquid engine called Raman-2, named after the Indian Nobel laureate CV Raman. A liquid engine can be throttled, its fuel flow turned up, turned down, or shut off entirely. Every stage before the OAM was built for raw thrust. The Orbit Adjustment Module is built for control. This episode is about the liquid-powered stage that can start, stop, and restart in space.#JourneyToOrbit #Vikram1 pic.twitter.com/SRG9Xjwepq— Skyroot Aerospace (@SkyrootA) June 21, 2026 That single ability changes everything. In the vacuum of space, the Raman-2 engine can fire, fall silent, and fire again, as many times as a mission demands. Each restart lets the stage shift the rocket into a fresh orbit, which is how one launch can drop several satellites at several addresses, a service the industry cheerfully calls a space taxi. The Raman-2 liquid engine, named after physicist CV Raman, can fire, shut down and restart in the vacuum of space.
(Photo: Skyroot) The engine is also 3D-printed and regeneratively cooled, a neat trick in which the cold fuel circulates around the engine walls before it burns, carrying away heat that would otherwise melt the metal. The propellant doubles as its own coolant. THE STEERING IS DONE BY WHISPERS A main engine alone cannot aim with the delicacy orbit demands. So the OAM carries a small orchestra of helpers, four Raman Mini thrusters and eight cold gas thrusters. Cold gas thrusters are the simplest rocket devices ever made, with no flame at all. They release a measured puff of pressurised gas, the same principle as releasing an inflated balloon, to turn the stage a fraction of a degree. Skyroot engineers monitor the Orbit Adjustment Module during ground testing, which ran for more than 1,000 thruster pulses. (Photo: Skyroot) They are precious precisely because nothing burns, so almost nothing can fail. Together these systems control pitch and yaw, the up-and-down and side-to-side tilt of the stage, nudging the path until the orbit is not roughly right but exactly right.
