The RS-2200 Linear Aerospike Engine is being developed for use on the Lockheed Martin Skunk Works’ Reusable Launch Vehicle, the production follow-on to the X-33. The Aerospike allows the smallest, lowest cost RLV to be developed because the engine fills the base, reducing base drag, and is integral to the vehicle, reducing installed weight when compared to a bell-shaped engine. The. Aerospike is the same as bell shaped rocket engines except that its nozzle is open to the atmosphere. The open plume compensates for decreasing atmospheric pressure as the vehicle ascends, keeping the engine’s performance very high along the entire trajectory. This altitude compensating feature allows a simple, low-risk gas generator cycle to be. used. Over $500 million were invested in Aerospike engines up to the contract award date of the X-33, and full size linear engines have accumulated 73 tests and over 4,000 seconds of operation. Throttling, Percent Thrust: 20-109. Dimensions: Forward End: 6.4 m wide X 2.36 m long. Aft End: 2.36 m wide X 2.36 m long. Length: 4.32 m. Designed for booster applications. Gas generator, pump-fed.

Linear aerospike engine for X-33 SSTO technology demonstrator. Based on J-2S engine developed for improved Saturn launch vehicles in the 1960's. Gas generator cycle; throttling 40% to 119% of nominal thrust; differential thrust between two engines plus-minus 15%. X-33 Advanced Technology Demonstrator Development. Designed for booster applications. Gas generator, pump-fed.