During one of their frequent late-night walks in the hills near their house, one of the kids saw two shooting stars streak across the quiet sky during the Perseid meteor shower.
The idea of working on Mars time goes back to the 1997 Pathfinder mission, which sent the first rover to the Red Planet.
The beetle-like Sojourner rover was designed to skitter around the surface for a week, sending back data once a sol. Members of the Pathfinder team wanted to analyze the results as quickly as possible so they could plan the rover’s next moves. To minimize delays, they decided to work on Mars time too.
Sojourner kept going all week, then continued for a second and a third. The Earthlings did their best to keep up, but after a month they’d had enough.
“The team rebelled,” said Andrew Mishkin, a senior systems engineer on that mission who has endured three stints on Marstime himself. “They were just too exhausted to continue.”
Living on Mars time is like moving two time zones to the west every three days, causing scientists and engineers to feel constantly jet-lagged. That throws off the body’s internal clock, which is synced to a 24-hour day and reset by light and dark.
When that system is out of whack for several weeks, negative effects ripple throughout the body.
At first, JPL had no formal policies to keep scientists and engineers from working themselves to the edge of their physical limits. They often logged 18 hours a day, and many tried to stick with Earth time when they were off duty, leaving them utterly drained, Mishkin said.
After the Pathfinder mission ended, JPL asked a panel of sleep experts for advice. The key, the experts said, was to keep the body clock on track so that people could sleep during their “night” and stay alert during their “day.”