to keep people on the ground safe, it's best to deorbit a spacecraft with a strong burn of propellant, to slow it down at the right time.
为确保地面上人的安全,最好的方法是以一个强大的推进器燃烧来使宇宙飞船脱轨,在正确的时间使其慢下来。
the mir station, to which the kvant, kvant-2, and kristall research modules were later docked, was in orbit from february 20, 1986 until its successful deorbit in 2001.