The Space Shuttle’s iconic, orange colored, external tank originally weighed in at 76,000 pounds. Made of aluminum 2219 alloy, it contained 535,000 gallons of liquid fuel, hydrogen and oxygen. At 154 feet tall, its height dwarfed the Wright Brother’s first flight by over 30 feet. Considered by many to be the structural backbone Shuttle System, It connect all four pieces of the launch stages together, the Orbiter, and two solid rocket boosters or SRB’s. This tank was designed to withstand over 7 Million pounds of thrust at launch.
In 1983, a redesign was introduced for the STS-6 Shuttle mission; this redesign decreased the weight of the tank by 10,000 pounds. Each pound removed in weight resulted in an increase in payload for the Orbiter. In 1986 Lockheed Martin Laboratories in Maryland took up the mission to develop a new high strength, and lower density replacement for the
2219 alloy. Design characteristics should maintain the weldability and fracture resistance of its predecessor but yield a lighter alloy. The result of this is the family of Aluminum-Lithium alloys called Weldalite®. The 2195 alloy was chosen for its 30 percent strength increase and 5% reduction in density.
Credit: https://www.nasa.gov
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