The vehicle consists of a slender fuselage containg propellant tankage and payload bay, with delta wings attached midway along the fuselage carrying the Sabre engines in axisymmetric nacelles on the wingtips. The vehicle takes off and lands horizontally on it's own undercarriage.

The Sabre engines have a dual mode capability. In rocket mode the engine operates as a closed cycle Lox/Lh2 high specific impulse rocket engine. In airbreathing mode (from takeoff to Mach 5) the liquid oxygen flow is replaced by atmospheric air, increasing the installed specific impulse 3-6 fold. The airflow is drawn into the engine via a 2 shock axisymmetric intake and is cooled to cryogenic temperatures prior to compression. The hydrogen fuel acts as a heatsink for the closed cycle helium loop before entering the combustion chamber.