Whereas chemical rockets waste too much propellant to reach a net change in spacecraft velocity, electric thrusters can do exactly the same mission using just a small fraction of the propellant.

鉴于化学燃料火箭浪费太多的推进剂难以实现飞船速度的静变化，电力推进器仅仅使用一小点推进剂就可以做同样的任务。

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Some satellites come equipped with a rocket engine and propellant tank so controllers can aim their descent into an ocean instead of a neighborhood, but not all.

而有些卫星则装配了火箭发动机和推进剂贮箱，这样可以控制它们的坠落路线，将其引导坠落到海洋之中，而不是坠落到居民区里。

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Neil McClelland, a spokesman for Kleinmann in Britain, said the signs so far were that the culprit was the anti-corrosion liquid inside the propellant can.

克莱恩曼公司在英国的发言人Neil McClelland说，到目前为止已有迹象表明，气溶胶推进剂罐内的防腐液是问题根源所在。

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