Martin HATV Credit - © Mark Wade

The Martin HATV 1946 design used a single Aerojet engine of unconventional design to achieve single-stage-to-orbit performance.

The Glenn L Martin's company HATV design used a single enormous Aerojet liquid oxygen/hydrogen engine to achieve single-stage-to-orbit performance. The unconventional transpiration-cooled engine did not use a traditional convergent-divergent nozzle. Instead the cylindrical combustion chamber opened directly into a long conical nozzle. A permeable stainless steel inner liner cooled the walls using liquid hydrogen. Chamber pressure was 34 atmospheres, sea level specific impulse 310 seconds, and vacuum specific impulse 425 seconds. The design used integral oxygen and hydrogen tanks with a common bulkhead. V-2-type fins provided aerodynamic control at low speed. They would be jettisoned when they became ineffective, with jet vanes at the base of the expansion nozzle providing vehicle control thereafter. Magnesium was used in the nose compartment structure and steel in the nose cone.

This 1946 design represented an early collaboration between Martin and Aerojet, which would be continued in the Titan series of rockets into the 21st Century.

Manufacturer: Martin. Liftoff Thrust: 1,334.000 kN (299,895 lbf). Total Mass: 46,550 kg (102,620 lb). Core Diameter: 4.39 m (14.40 ft). Total Length: 23.50 m (77.00 ft).