XLR-129
Encyclopedia
The XLR-129 was an ill-fated American rocket engine
that used liquid hydrogen/liquid oxygen propellant. It was developed by Pratt & Whitney
and initially was to develop 250,000 lbs of thrust.
The XLR-129 was designed to be reusable and was initially paid for by the US Air Force, for a 1960s program called ISINGLASS
which was to be a manned rocket plane that was intended for surveillance overflights.
For the Space Shuttle
an attempt was made to increase the thrust to 350,000 lbs, but in the end Rocketdyne
's Space Shuttle Main Engine
was used instead.
The XLR-129 program was never completed, no complete engine was ever produced, but many systems were developed and tested.
Rocket engine
A rocket engine, or simply "rocket", is a jet engineRocket Propulsion Elements; 7th edition- chapter 1 that uses only propellant mass for forming its high speed propulsive jet. Rocket engines are reaction engines and obtain thrust in accordance with Newton's third law...
that used liquid hydrogen/liquid oxygen propellant. It was developed by Pratt & Whitney
Pratt & Whitney
Pratt & Whitney is a U.S.-based aerospace manufacturer with global service operations. It is a subsidiary of United Technologies Corporation . Pratt & Whitney's aircraft engines are widely used in both civil aviation and military aviation. Its headquarters are in East Hartford, Connecticut, USA...
and initially was to develop 250,000 lbs of thrust.
The XLR-129 was designed to be reusable and was initially paid for by the US Air Force, for a 1960s program called ISINGLASS
Isinglass
Isinglass is a substance obtained from the dried swim bladders of fish. It is a form of collagen used mainly for the clarification of wine and beer. It can also be cooked into a paste for specialized gluing purposes....
which was to be a manned rocket plane that was intended for surveillance overflights.
For the Space Shuttle
Space Shuttle
The Space Shuttle was a manned orbital rocket and spacecraft system operated by NASA on 135 missions from 1981 to 2011. The system combined rocket launch, orbital spacecraft, and re-entry spaceplane with modular add-ons...
an attempt was made to increase the thrust to 350,000 lbs, but in the end Rocketdyne
Rocketdyne
Rocketdyne was a Rocket engine design and production company headquartered in Canoga Park, California, United States. The company was related to North American Aviation for most of its history. NAA merged with Rockwell International, which was then bought by Boeing in December, 1996...
's Space Shuttle Main Engine
Space Shuttle main engine
The RS-25, otherwise known as the Space Shuttle Main Engine , is a reusable liquid-fuel rocket engine built by Pratt & Whitney Rocketdyne for the Space Shuttle, running on liquid hydrogen and oxygen. Each Space Shuttle was propelled by three SSMEs mated to one powerhead...
was used instead.
The XLR-129 program was never completed, no complete engine was ever produced, but many systems were developed and tested.