The Napier Scorpion was a British liquid-fuelled rocket engine developed and manufactured by Napier

Napier & Son

D. Napier & Son Limited was a British engine and pre-Great War automobile manufacturer and one of the most important aircraft engine manufacturers in the early to mid-20th century...

. It used hydrogen peroxide / kerosene propellant chemistry.

Double Scorpion

From 1956 the Double Scorpion NScD.1
was fitted experimentally to two Canberra light bomber

English Electric Canberra

The English Electric Canberra is a first-generation jet-powered light bomber manufactured in large numbers through the 1950s. The Canberra could fly at a higher altitude than any other bomber through the 1950s and set a world altitude record of 70,310 ft in 1957...

s, to improve high altitude performance.

A world altitude record of 70300 feet (21,427 m) was set by Canberra WK163 on 28 August 1957. This was on the eve of cancellation of manned aircraft programmes by the 1957 Defence White Paper

1957 Defence White Paper

The 1957 White Paper on Defence was a British white paper setting forth the perceived future of the British military. It had profound effects on all aspects of the defence industry but probably the most affected was the British aircraft industry...

.

The Double Scorpion was also considered for use in the English Electric P.1A interceptor (which gave rise to the Lightning

English Electric Lightning

The English Electric Lightning is a supersonic jet fighter aircraft of the Cold War era, noted for its great speed and unpainted natural metal exterior finish. It is the only all-British Mach 2 fighter aircraft. The aircraft was renowned for its capabilities as an interceptor; Royal Air Force ...

) The company Aerojet General was chosen for United States production.

Cancellation

The Scorpion project was cancelled in February 1959, at a reported total cost of £ 1.25 million.