I quickly increased our speed, calculating the time it would take for the weapons-most likely SA-2 and SA-4 surface-to-air missiles capable of Mach 5 - to reach our altitude.
Back to this starting point — if we call this sort of a starting point, - starting altitude — this whole trip will take twice the amount of time.
回到出发点的轨迹-，如果我们把这个称之为出发点，出发的高度-，整个过程将会耗费，2倍的这个时间。
3
The implication is that, at altitude, players might be coached to have a go at goal from longer distances to take advantage of the straighter, faster trajectories.