AKA: External Tank. Status: Study 1989. Gross mass: 750,975 kg (1,655,616 lb). Unfuelled mass: 29,930 kg (65,980 lb). Specific impulse: 455 s. Specific impulse sea level: 363 s. Burn time: 480 s. Height: 46.88 m (153.80 ft). Diameter: 8.40 m (27.50 ft). Span: 8.70 m (28.50 ft).
|Shuttle Super Lightweight Tank LOx/LH2 propellant rocket stage. The Super Lightweight Tank used 2195 Aluminum-Lithium alloy as the main structural material in place of the 2219 aluminum alloy of the original design. This saved 3,500 kg in empty mass, increasing shuttle payload by the same amount. This change was made in anticipation of Shuttle-Mir and Shuttle-ISS flights to high inclination 51.6 degree orbits. The tank was first used on STS-91 in June 1998.|