Project Pluto was a United States government program to develop nuclear-powered ramjet engines for use in cruise missiles. Two experimental engines were tested at the Nevada Test Site (NTS) in 1961 and 1964 respectively.
Tory-IIC nuclear ramjet
Schematic cross-section of Tory reactor
Building 2201 from above
The Tory-IIA prototype
A ramjet is a form of airbreathing jet engine that requires forward motion of the engine to provide air for combustion. Ramjets work most efficiently at supersonic speeds around Mach 3 and can operate up to Mach 6.
An AQM-60 Kingfisher, the first production ramjet to enter service with the US military
Upper engine is a ramjet on the Bloodhound missile
Leduc 010
Bristol Thor ramjet modified for display purposes. Two Thor engines were used on the Bristol Bloodhound missile