Status Name Nationality Thrust** Propellants Notes Out-of-production F-1 USA 1.7 million Liquid Oxygen - Kerosene 5 used in each Apollo Saturn Stage 1. Flown between 1967 to 1973. Development stopped RD-270 USSR 1.5 million Nitrogen Tetroxide – UDMH Tested, but never flown. Largest single-chamber engine designed by USSR. Development stopped M-1 USA 1.2 million Liquid Oxygen – Liquid Hydrogen Designed as replacement for F-1. Program canceled in 1966. In production BA-810 USA 810,000 Hydrogen Peroxide - Kerosene Stage 2 engine of BA-2 launch vehicle. First test 1Q 2000; first flight 2002. In production RS-68 USA 745,000 Liquid...