Sabre is an acronym for “Synergic Air BReathing Engine”, a type of engine that was developed around the 1980s, baptized as LACE or “Liquid Air Cycle Engine” for the HOTOL project.

-The Rolls-Royce RB.545 was also included in the HOTOL project. (see also “Reaction Engines Limited”).

-In fact, both engines are turbo-rockets that use oxygen from the lower atmosphere and liquid oxygen in a vacuum.

-The fuel in both is liquid Hydrogen.

“Sabre engine nacelle, schematic drawing”

-The Sabre has been directed to equip the “Skylon” Shuttle aircraft project.

-It has two engines at the ends of the wings, as we can see in the below figure.

-More than larger in size, since it was going to be about 80 meters long.

“Skylon, side design”

From Appendix 6: See Reaction Engines Limited. It develops a space propulsion system that takes advantage of oxygen in the atmosphere and uses rocket engines in a vacuum.

-It uses an evolution of the system or technology called LACE or “Liquid-Air Cycle Engine”, being a solution for flights that begin on the Earth's surface to reach the stratosphere and beyond.

“Sabre engine”

-This illustration is recent, received from a collaborator. The simplified engine cycle is also attached.

-This engine is capable of 5.5 Mach in the atmosphere and 25 Mach in a vacuum.

-The thrust ranges between 200 to 300 Tons.

“Sabre cycle diagram”