Silver News

Precedent-Breaking Space Shuttle Flight Relied on Silver

By Samuel Etris, Senior Technical Consultant to The Silver Institute

John Glenn's historic Space Shuttle mission was powered into space by a metallurgical breakthrough: a lighter weight fuel tank whose aluminum-lithium-silver alloy reduced the Shuttle's booster weight by more than four tons.

The new silver-containing aluminum alloy was developed at Lockheed Martin Laboratories in Baltimore, Maryland, and was field-tested for over ten years. The new high-strength, aluminum-lithium-silver alloy, called "Weldalite AA2195," reduced the dry tank weight from 75,569 to 65,500 pounds. In a Space Shuttle launch, the booster tank is the prime structural element, representing about 80 percent of the vehicle's dry weight. Any reduction in its weight is critically important.

As the cost of freight carried into space is about $10,000/pound, saving weight has high priority. For the construction of the International Space Station, the more freight a single Space Shuttle can carry, the less the cost of assembly. Thus the 10,000 pound reduction in the booster tank weight is critical toward keeping the cost of the Space Station within budget.

The new aluminum-lithium-silver tank not only supplied fuel for the 7 million-pound thrust during the first two minutes of the mission but it supported the 250,000-pound shuttle at takeoff and withstood the violent transition from rest to supersonic flight. Its success opens a new chapter for silver in aerospace applications.

Silver News - December 1998/January 1999