India's deep-space missions might get a Russian boost soon
What's the story
The Indian Space Research Organization (ISRO) has held technical talks with Russia's space agency Roscosmos in Moscow. The discussions were centered around the delivery of semi-cryogenic engines, which are critical for India's future heavy-lift launch vehicles. A draft contract for these engines is currently under approval, as per ISRO's Annual Report 2025-26.
Engine details
What are semi-cryogenic engines?
The semi-cryogenic engine is a vital technology for India's upcoming heavy-lift launch vehicles. It runs on a mix of refined kerosene and liquid oxygen, providing more efficiency and thrust than current systems. The development and induction of such engines are expected to boost India's launch capabilities for heavier payloads and deep-space missions.
Program progress
ISRO's own engine development
ISRO has been working on its own semi-cryogenic engine program. The agency had said in a March 2025 statement that it was "achieving progress in the design & development of a semicryogenic engine or Liquid Oxygen / Kerosene engine with a high thrust of 2000 kN that will power the semicryogenic booster stage of the LVM3 launch vehicle." This will power the semicryogenic booster stage of the LVM3 launch vehicle.
Engine development
What is the SC120 stage?
The Liquid Propulsion Systems Centre (LPSC) of ISRO is developing the semi-cryogenic propulsion engine and stage. The SC120 stage, powered by the 2000 kN semi-cryogenic engine (SE2000), will replace LVM3's current core liquid stage (L110) for payload enhancement. It will also power booster stages of launch vehicles in the future.
System upgrade
How will it enhance LVM3?
ISRO's semi-cryogenic propulsion system, along with an uprated cryogenic stage in the LVM3 vehicle, will boost its payload capability from four tons to five tons. The major subsystems of the SE-2000 engine include thrust chamber, pre-burner, turbo pump system, control components and start-up system. "The SE2000 engine works with complex oxidizer rich staged combustion cycle with high chamber pressure of 180 bar & specific impulse of 335s (with propellant feed system delivering pressures up to 600 bar)," the agency said.