Sixteen sunrises, and what they do to your sleep

At four hundred and twenty kilometers you complete an orbit every ninety-two minutes, which means the sun comes up sixteen times in what your watch still insists is one day. Your circadian system, tuned over a few hundred thousand years to a single sunrise, finds this objectionable.

We schedule the dark

The cabin runs on a fixed ground clock and the windows have shades. We dim the cabin lights to a warm, low color in the crew’s evening regardless of what the sun is doing outside, and we are strict about it, because sleep is the single biggest lever on how a passenger feels and performs for the rest of the flight.

It still gets everyone, once

Almost every passenger sneaks at least one look at an unscheduled sunrise, usually around the third night, camera in hand, shades cracked. We pretend not to notice. Some things are worth a little lost sleep, and a sunrise with no atmosphere to soften it, gold to white in under a second, is one of them.