Rocketdyne XRS-2200

The Rocketdyne XRS-2200 was an experimental linear aerospike rocket engine that Rocketdyne developed in the mid-1990s for the Lockheed Martin X-33 technology demonstrator. Instead of a bell nozzle it used a linear aerospike nozzle, and its powerpack, the turbomachinery and gas generator, was derived from the J-2 engine that powered the upper stage of the Saturn V, so it kept the J-2 combustion cycle and propellant choice. It was the subscale step toward the RS-2200, the version Rocketdyne intended to develop for the VentureStar. The X-33 program was cancelled, but two XRS-2200 engines were produced and tested before development ended.