During the late 1950s there was a very real fear that the Soviets would soon have bombers capable of cruising at altitudes of over 60,000 feet. Along with several other companies, Vought sought means by which jet fighters could be able to reach such altitudes and deal with these threats. One technique that was studied was the installation of an auxiliary rocket engine that could help boost the fighter to such high altitudes. In 1957, Vought planned to install a rocket engine in the tail of a couple of F8U-1s (production numbers 16 and 23). The engine originally planned for this installation was the Reaction Motors XLR-40 which provided 8000 pounds of thrust and was fuelled by a mixture of hydrogen peroxide and jet fuel. Unfortunately, this rocket engine exploded during an early ground test, killing two company mechanics. This accident caused Reaction Motors to pull out of the project.
Propellant Formulation: H2O2/JP-4.
Thrust: 35.69 kN (8,023 lbf).