Check the listing for details. SPACE SHUTTLE SUPER LIGHTWEIGHT EXTERNAL TANK MISSION SUCCESS MEDALLION KEYCHAIN. Condition: New. Listed at 12.00 USD. SPACE SHUTTLE SUPER LIGHTWEIGHT EXTERNAL TANK MISSION SUCCESS MEDALLION KEYCHAIN AB ANTIQUE BRONZE 1.5" DIAMETER MEDALLION / KEYCHAIN the third generation—is the Super Lightweight External Tank, first flown on STS-91 in June 1998. The tank, primarily made of an aluminum-lithium alloy, is 7,500 pounds lighter than the previous design, the Lightweight Tank. The stronger, lighter alloy—and other weight-sav ing design changes—places the new Super Light weight Tank at about 58,500 pounds empty, and 1.6 million pounds when filled with propellants. The lighter tank enables the Space Shuttle to carry heavier components, such as those being used to assemble the International Space Station. Track Page Views WithAuctiva's Counter