A space shuttle main engine burns at 6,000 degrees F, but the outside of the nozzle remains cool to the touch. Prior to launch, sometimes it even frosts over. The nozzle technology that allows a finger-width of ridged metal to contain and steer flames that would boil iron is just one of the scores of innovations designers came up with for the engines three decades ago.
Such advances were critical if NASA was going to realize its plans for a reusable space shuttle that, unlike the previous rockets, would not use its engines once and then drop them in the ocean.Some of the others:
- A system that lets the engines be incrementally throttled up and down depending on the needs of the mission
- A hydrogen turbo pump spins 567 times a second with each 2” tall turbine blade generating 700 horsepower.
- A computer that runs 50 health checks on the engine every second using data from 200 sensors
- A system of pipes, or ducts, those withstand pressures as high as 7,000 pounds per square inch
- A main combustion chamber strong enough to contain the explosion of 970 pounds of oxygen and 162 pounds of hydrogen fuel every second, continuously for 8 1/2 minutes
- The only heavy-lift booster engine that continuously performs all the way from launch pad to orbit
- Engineering and materials that allow the engine to be reused multiple times
- A compact, efficient design that produces 8 times the thrust of a modern high performance jet engine per each pound of weight.
