The atmospheric pressure as we climb is getting so low 气压在逐渐减小

that without any air supply,I'd be unconscious within 20 seconds. 如果不戴呼吸器 不用20秒我就会休克过去

I have to breathe 100% oxygen to avoid getting nitrogen bubbles in my bloodstream,which could be fatal. 为避免氮气 在我的血液中形成气泡致死 我只能吸纯氧

Last time I was up at 30,000 feet was on the summit of Everest. 上一次到3万英尺高 还是在珠峰的时候

Jumping at this altitude is a technique used by special forces for covert insertions. 在这种高度跳伞 是特种部队进行渗透的惯用伎俩

Mimicking the flight path of commercial jets is an effective concealment and deploys troops fast without detection. 其最隐蔽的方式就是 混入商业航线之中 部署天降神兵

It's known as high-altitude-low-opening,or HALO. 这就是常说的高跳低开

I've got t-minus two.Two minutes to jump. 还有2分20秒准备时间 2分后开始伞降

The temperature has plummeted to minus-40. 舱外气温已跌至零下40度

Exit the plane without my goggles,and my eyes would freeze instantly. 如果不戴护目镜的话 我的眼球会在瞬间冻结

Down on the desert floor, it's over 100. 地面温度已超过华氏100度

I'm about to put myself through a temperature change of 140 degrees in less than 5 minutes. 我将在5分钟内体验 接近80度的温差

I'm wired up so that my team can measure my body stats on my descent.Okay, let's go. 我身上捆满了各种设备 以便摄制组 在下降的时候检测我的状况 好 出发

In six seconds, I hit terminal velocity. 六秒内 我便达到了自由沉降速度

It's impossible to fall any faster. 这就是下降的最快速度了

And because the air is thinner at this altitude, 由于这个高度的大气很稀薄

I'm falling at just under 200 miles an hour. 我的下落速度接近每小时321公里

We're in HALO free fall!Just amazing.Okay, altitude check.26,000 feet and falling fast. 我们在高跳低开 太爽了 查看高程 2万6千英尺 仍在快速下降