The design, development, and qualification of an advanced columbium liquid apogee engine (AC-LAE)

Advanced spacecraft have a requirement for high performance liquid apogee engines (LAEs) to increase onorbit payload or on-orbit life. Alternatively, for a given spacecraft dry mass and orbit insertion delta V, the propellant mass reduction made possible by an advanced LAE may enable the use of a smaller launch vehicle, with significant cost savings. In 1996 TRW successfully completed the development and qualification of an advanced LAE that delivers a thrust of 106 Ibf with a nominal specific impulse (Isp) of 322 seconds, using N2H4/N2O4 propellant combination. The engine features TRW's high performance coaxial pintle injector and an industry standard disilicide coated columbium alloy (C103) thrust chamber, hence the name Advanced Columbium Liquid Apogee Engine (ACLAE). This paper provides a detailed description of the AC-LAE design, a summary of the development and qualification test phases, and the engine performance and thermal characteristics.