Now on 'Mars time,' NASA's Perseverance team has to shift their work hours 40 minutes later every day

• NASA's Perseverance rover just landed on Mars.
• Now about 350 of its engineers and scientists have to work on "Mars time," shifting their hours 40 minutes later each day.
• Since this requires overnight shifts and causes jetlag, NASA only asks them to do it for three months.

NASA just landed a new rover on Mars, the culmination of a 300-million-mile journey that sent the robot into ancient lake bed.

But the landing is just the beginning of the Perseverance rover's mission. It's set to explore Mars' Jezero Crater for the next two years. It will search for signs of ancient microbial life that could have gotten trapped in sediment from the river that flowed into the lake. Perseverance aims to collect about 40 samples of Martian rock and soil, which it will save so that a future NASA mission can bring them back to Earth.

At NASA, the team of scientists and engineers behind the Perseverance surface operations have to work around the robot's schedule. That means about 350 people will be keeping "Mars time" for the next three months - shifting their workdays 40 minutes later every day.

"The team is going to get used to getting up later and then working a little bit into the night. That's not bad, to be on a different shift, but the problem with Mars time is that the Mars days are 40 minutes longer than the Earth days," Jennifer Trosper, who has worked on all five of NASA's Mars rovers and serves as deputy project manager for this one, said in a briefing before the landing.

The team usually starts work during the Martian afternoon, because that's when the rover's data dump reaches Earth. They work for 12 to 14 hours to prepare an upload to send back to the rover. The first shift in this cycle began at around 2 p.m., Trosper said, then it is shifting 40 minutes later every day. After 37 days - a full "cycle" - the shifts are back where they started.

"The reason we do Mars time is because it is the most efficient way to have the rover make progress on a day-to-day basis. And that's really important early in the mission to get it kind of unbuckled and ready to go," Trosper said.

The first tasks the team will do with the rover on this strange schedule involve checking all its systems, science instruments, and hardware. Then it has to drive to a field and release the tiny helicopter it carried to Mars. The drone will conduct some test flights, and after that, Perseverance can begin its sample-collecting work.

But the constantly changing work hours are not easy for humans, so NASA only asks people to do that for three months.

"The first cycle everybody's excited: 'This is cool. I'm on Mars time,'" Trosper said. "By the next cycle, people start to get a little bit tired. And by the third, by the time we finish Mars time, they are well ready to be finished with Mars time. It's hard on your body. It's like being jet lagged."

Ahead of Perseverance's landing, she added, she finally bought an eye mask to help her sleep through sunlight hours.

"It took me five missions to figure this out," Trosper said. "So I'm ready. I have my earplugs, and we'll be on Mars time."

The wonky schedule is especially complicated this year, since the pandemic means so many team members are working home. Taking 4 a.m. conference calls might be disruptive to sleeping family members or roommates.

So NASA has set up some socially distanced on-site places for team members to come in if they want to.

Trosper said "a couple dozen people" plan to take advantage of this option during the next three months. That way, she said, "they can not interfere with their family's life, which is not on Mars time."