First, watch it:
By Sean Goebel:
I filmed when the telescopes were doing interesting things (LASERS!), the weather was hopeful, the moon phase was small, and people to drive with were available. This combination of requirements often dictated that I go up on weeknights. I was unwilling to take time off work, so on multiple occasions I worked until the evening, rushed home to grab gear, drove up the mountain, shot timelapse all night, arrived home around sunrise, slept 1-2 hours, and then headed into work for the next day. Coffee, I love you.
A typical scene took about 5 hours to film (300 1-minute exposures), and I had two cameras, so I could generally film two scenes per night. I had one chance to get it right, and mistakes were far more likely at 14,000 ft (4200 m). The temperatures were generally around freezing, and there often were high winds. We typically spent the first several hours per night driving around and setting up cameras.
Read the rest here.