There have been two failures: The shuttle Challenger and seven astronauts were lost just after launch in January 1986 due to an O-ring seal leak in a solid rocket booster that led to an explosion.

有两次失败的教训：1986年1月刚刚发射过后，一个固体火箭助推器的O型圈密封泄漏导致的爆炸，使我们失去了挑战者号和7名宇航员。

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Despite an earlier leak claiming that there would be a two-tier system - similar to the old O-levels and CSEs - the new qualification will be a single exam for a wide range of abilities.

BBC: GCSEs replaced by 'English Bac' in key subjects