Skip to content
79,433 pages · 13,741 images · since 1994 Browse A–Z Today in space history
Encyclopedia Astronautica The full story of spaceflight
Encyclopedia entry

Liquid Air/Lox/LH2

Propellant

Original archive entry. The text, images and links below are kept as they were written.

Liquid Air/Lox/LH2 propellant. Liquid air has no advantage as a stored propellant, but in a Liquid Air Cycle Engine (LACE) relatively freely available atmospheric air is scooped up, liquefied, and burned with a fuel in a conventional rocket engine. In this variant, liquid oxygen is used to continue operation of the engine above the atmosphere, allowing the engine to be used in single-stage-to-orbit designs. This approach was used by Rolls Royce in the RB545 engine proposed for the HOTOL spaceplane, but later abandoned for the simpler Air/Lox/LH2 Sabre engine for the proposed Skylon SSTO.

Fuel Density: 0.071 g/cc. Fuel Freezing Point: -259 deg C. Fuel Boiling Point: -253 deg C.

Subtopics

  • RB545 Rolls Royce air augmented rocket engine. Used Liquid Air/LOx/LH2. Development ended 1985. Used on HOTOL launch vehicle.
Engines
RB545