A new Space Shuttle fuel tank developed to launch the International Space Station is scheduled for its maiden flight next week on the final U.S. mission to dock with Russia's Mir Space Station.
The Shuttle's new, super lightweight external fuel tank is the same size as the tank it replaces -- but about 7,500 pounds lighter. The weight reduction is essential for launching heavy pieces of the Space Station for assembly on orbit. Since the external tank goes all the way to orbit before it's jettisoned from the Shuttle, each pound removed from the tank equals a pound of payload that can be carried into space.
The tank is the largest single component of the Space Shuttle. Standing 154 feet tall, the gigantic external tank is taller than a 15-story building and is as wide as a silo with a diameter of about 27 feet.
The external tank holds the liquid hydrogen and liquid oxygen propellants in two separate tanks to fuel the Shuttle's three main rocket engines. The external tank program is managed by NASA's Marshall Space Flight Center in Huntsville, Ala.
The super lightweight tank features major changes in materials and design. Both the liquid hydrogen tank and the liquid oxygen tank are constructed of aluminum lithium -- a lighter, stronger material than the metal alloy used to manufacture the previous external tanks.
The tank's structural design also has been improved. The walls of the redesigned hydrogen tank are machined in an orthogonal waffle-like pattern, providing more strength and stability than the previous design.
"The first flight of the super lightweight tank culminates four-and-a-half years of very intensive effort to bring this brand new material, aluminum lithium, to flight status," said Parker Counts, manager of the Marshall Center's External Tank Project.
At least 25 super lightweight tanks will be required for Space Station assembly missions. About a dozen tanks are currently in various stages of processing and assembly. The new design does not affect the assembly process in which the Shuttle orbiter is mated to the external tank and solid rocket boosters.
The external tank is manufactured by Lockheed Martin at the Michoud Assembly Facility in New Orleans. In addition to the external tank, the Marshall Center provides the main engines and solid rocket boosters, including the reusable solid rocket motors, for every Shuttle flight.
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Note to Editors: Photos and video supporting this release are available to media representatives by contacting June Malone, Media Relations Office, Marshall Space Flight Center, (256) 544-0034.