The greatest concern the authors raise is space debris—pieces of "junk" that orbit the earth, with the potential to cause serious damage if they collide with operational units, including the ISS.

作者提出的最大担忧是太空碎片，即环绕地球的“垃圾”碎片，如果它们与包括国际空间站在内的运行体相撞，将有可能造成严重损害。

youdao

The greatest concern the authors raise is space debris-pieces of "junk" that orbit the earth, with the potential to cause serious damage if they collide with operational units, including the ISS.

两位作者提出的最大担忧是太空垃圾——环绕地球运行的“垃圾”碎片，如果它们与包括国际空间站在内的运行单位相撞，可能会造成严重损害。

youdao

If the tiniest piece of junk crashed into a spaceship, it could damage the vehicle.

即使是最微小的一块废品撞到宇宙飞船上，也会损坏飞船。

youdao

"They are all hurtling around in space at 36,000 kilometers per hour and so even a 1mm piece of space junk can destroy or damage a satellite because it all comes from either dead satellites, satellites which have broken up, satellites which had fuel left in them and exploded."

VOA: standard.2010.07.24