LEROS is a family of chemical rocket engines manufactured by Nammo [1] at Westcott, Buckinghamshire, United Kingdom. LEROS engines have been used as primary apogee engines for telecommunications satellites such as the Lockheed Martin A2100 [2] as well as deep space missions such as Juno. [3] The LEROS engines are made of niobium alloy, which is traditionally used for liquid rocket engines such as the attitude control thrusters of the Apollo Lunar Module.
Engine | Propellant | Thrust | Isp | Comments |
---|---|---|---|---|
LEROS 1c [4] | Hydrazine / MON | 460 N | 325 | |
LEROS 1b | Hydrazine / MON | 635 N | 318 | |
LEROS 2b | MMH / MON | 407 N | 318 | |
LEROS 4 | MMH / MON | 1100 N | 323 [5] | Developed c. 2014 for European Space Agency's (ESA) Mars Robotic Exploration Program [6] |
The family of engines derives from the LEROS 1 which was developed and qualified in the 1990s by Royal Ordnance. The in-space propulsion business was acquired by British Aerospace, then had a sequence of owners including American Pacific Corporation, Moog [7] (from 2012) and Nammo (2017). As of 2011, more than 70 LEROS 1 series engines had been flown successfully. [8]
LEROS engines have been used on a number of NASA and other space agency missions:
There have been helium check valve problems on Juno leading to postponed maneuvers, and a failure after the first burn on Intelsat 33e requiring backup low-thrust jets to be used to bring the satellite to its intended orbit. [15]