One of the three main engines that power a space shuttle into orbit. Each reusable engine weighs around 3 150 kg and is 4.3 m long and 2.28 m in diameter. The engines burn for 8.5 minutes during lift-off and ascent, consuming more than 1.9 million L of fuel (liquid hydrogen and liquid oxygen) in the immense external tank. The engines shut down just before the shuttle goes into orbit. The SSME was developed at NASA's Marshall Space Flight Center, where it was modified in 1988 and 1995. A further upgrade was completed in 2001.
Subjects: Astronomy and Astrophysics.