Huntsville in Madison County, Alabama — The American South (East South Central)
Main Engines
Power for Lift-off and Ascent to Orbit
The Pathfinders three main engines are real. The two lower engines powered the first flight of Columbia in 1981. The engine located at the top was used in ground test firings.
At launch, the three Space Shuttle Main Engines (fed liquid hydrogen and oxygen from the External Tank) are ignited several seconds before liftoff.
They operate for approximately 8.5 minutes of flight, drawing about 47,000 gallons of liquid hydrogen and 17,000 gallons of liquid oxygen each minute. Shortly before the shuttle achieves orbit the Main Engines shut down and maneuvering rockets fire to position the Shuttle into its final orbit. Reusable each engine is designed for 7.5 hours of operation or to endure up to 55 starts.
Data, Each Engine
Length: 14 ft
Diameter: 7.5 ft
Weight: approximately 7000 lbs.
Thrust: 393,800 lbs.
Mix ratio: 6 parts oxygen to 1part hydrogen
Prime Contractor: Rockwell International Rocketdyne Division
Topics. This historical marker is listed in these topic lists: Air & Space • War, Cold. A significant historical year for this entry is 1981.
Location. 34° 42.647′ N, 86° 39.156′ W. Marker is in Huntsville, Alabama, in Madison County. It can be reached from Tranquility Base 0.4 miles west of Madison Pike, on the left when traveling west. Touch for map. Marker is at or near this postal address: 1 Tranquility Base, Huntsville AL 35805, United States of America. Touch for directions.
Regionally, this marker is in North Alabama. It is also in the American South, specifically in the Deep South, in Appalachia, and specifically in Southern Appalachia. Globally, it is in North America, a Gulf of Mexico state, the Western Hemisphere, the Western World, and the Anglosphere. Historically, it finds itself in what was once the original Cherokee Nation, the territory of the Mississippian Culture, one of the Confederate States of America, and the Antebellum South.
Other nearby markers. At least 8 other markers are within walking distance of this marker: External Tank (a few steps from this marker); Seasoned Global Traveler (a few steps from this marker); The Orbiter (within shouting distance of this marker); Astronaut Facts (within shouting distance of this marker); Discovery, OV-103 (within shouting distance of this marker); Shuttle Training Aircraft (within shouting distance of this marker); Atlantis, OV-104 (within shouting distance of this marker); Flight Span 30 Years (within shouting distance of this marker). Touch for a list and map of all markers in Huntsville.
Also see . . . U.S. Space & Rocket Center. (Submitted on September 22, 2016.)
Credits. This page was last revised on July 9, 2024. It was originally submitted on September 21, 2016, by Sandra Hughes Tidwell of Killen, Alabama, USA. This page has been viewed 695 times since then and 16 times this year. Photos: 1, 2. submitted on September 21, 2016, by Sandra Hughes Tidwell of Killen, Alabama, USA. • Bernard Fisher was the editor who published this page.

