n.利用大氣之摩擦而減低太空船之運動速度

This process is a natural version of the aerobraking procedure that many planetary probes have used to enter orbit. 這可說是自然界的空氣煞車程序，許多行星探測船都得靠著空氣煞車來進入軌道。

In the coming months, MRO's orbit will be circularized through repeated passages into Mars' outer atmosphere, a process known as aerobraking, shrinking its orbit to an altitude of only 280 kilometers. 在接下來的幾個月里，MRO的軌道將重復經(jīng)過火星的外大氣層，這就是減速過程，它將軌道高度降低到只有280公里。