The space shuttle uses ATK's four-segment solid rocket boosters (SRBs) to do the major part of lifting the shuttle stack off the Earth.

BBC: New rocket could lift astronauts

Way back in November of 1985, on just its second mission, Atlantis experienced a blow-back of hot gases past the primary O-rings in one of its solid rocket boosters, resulting in serious erosion of said O-ring.

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It's almost the same mix as in the solid-rocket boosters on the Space Shuttle, and it's powerful stuff.

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The bottom part of the proposed Liberty rocket would be based on the solid-fuelled boosters that help get the shuttle off the ground.

BBC: New rocket could lift astronauts