X-33 Model

In the late 1990s, the United States experimented with a reusable, single-stage-to-orbit spaceplane. The final product would have been the VentureStar, a large rocket system which would not require discarding used stages like traditional rockets or disposable fuel tanks and solid rocket boosters like the Shuttle. It would have used a new type of rocket engine called the RS-2200 linear aerospike engine, composite hydrogen tanks, and a new type of thermal protection system.

Before jumping directly to the full-sized VentureStar, a sub-scale technology demonstrator program was undertaken in the form of the X-33 spaceplane and the XRS-2200 rocket engine.

Unfortunately, the X-33 program ran into developmental problems and was cancelled, and neither the XRS-2200 nor RS-2200 were chosen for any later program.

I have additional information on the X-33 on my XRS-220/RS-2200 Linear Aerospike Engine Data Sheets page.