Coping with Martian jet lag


Time: After the Mars rovers land, NASA scientists and engineers will be setting their alarm clocks 40 minutes ahead every night during the mission.

December 31, 2003|By Michael Stroh | Michael Stroh,SUN STAFF

The scientists whose rovers will explore the surface of Mars in January won't be leaving home themselves. But they'll have to get used to a hassle that no jet-lagged Earth traveler has ever faced: living on Martian time.

Beginning Saturday, when Spirit, the first of two NASA Mars buggies, is scheduled to touch down, more than 200 NASA personnel will begin waking, working and sleeping to the alien rhythm of the Martian day. It's only 39 1/2 minutes longer than our own, but that's enough to gum up the works of a human's internal clock.

The idea is to squeeze as much science as possible from the solar-powered rovers, which will search for signs of ancient water on the Red Planet. They're designed to last 90 days and must do most of their exploring when the sun is shining.

Although it sounds simple enough, that requirement will make life pretty strange. To keep up with the longer Martian day, scientists and engineers will be setting their alarm clocks 40 minutes ahead every night.

"In some ways, it's nice because it means you can sleep later every day," says Andrew Mishkin of NASA's Jet Propulsion Laboratory in Pasadena, Calif., where the Mars rovers will be operated.

On the other hand, it means a workday that began at 8 a.m. Earth time at the outset of the mission will begin about 10 p.m. three weeks later and 2:30 a.m. a week after that.

To help scientists and engineers adjust, NASA has enlisted experts who train long-distance pilots on how to battle fatigue. The agency has draped blackout curtains over the windows of the Jet Propulsion Lab's mission control room to keep the sun from messing up controllers' Martian-tuned body clocks. It has even ordered 150 custom-made Mars watches.

But the mission - the largest coordinated experiment in off-world living ever conducted - might also shed light on how humans would hold up on manned voyages to Mars, or in Martian colonies.

Investigators from NASA Ames Research Center at Moffett Field, Calif., are also recruiting 30 JPL volunteers to strap on watch-sized accelerometers. The devices, which record changes in motion, will help researchers deduce when Mars mission volunteers are snoozing. Volunteers will also keep track of catnaps in sleep journals.

"We're trying to see how people adapt," says study leader Melissa Mallis, director of Ames' Fatigue Countermeasures Group. In addition to its value for future Mars missions, Mallis says, the research might provide new insights into fatigue and sleep on Earth.

The problem of keeping time on Mars has intrigued scientists and science-fiction writers since the 19th century.

In February 1954, the Hamilton Watch Co. unveiled a Mars clock. Described as "the world's first inter-planetary timepiece" by The New York Times, the device had a 16-inch face and four dials that simultaneously showed the hour, day, month and year on Earth and Mars.

The principal designer, astronomer Israel Levitt of the Franklin Institute in Philadelphia, noted that the watch could help astronomers shoot time-lapse photos of Mars. He also told the Times it might become useful for human voyagers "in twenty years or so."

"People have thought about this for a long time," says Michael Allison, a scientist at the NASA Goddard Institute for Space Studies in New York who studies Martian timekeeping.

But it wasn't until NASA's twin Viking landers crunched down in 1976 that scientists began measuring time on Mars more precisely. Accurate timekeeping, says Allison, is essential for the study of weather and climate.

By convention, a Martian day (known as a "sol") is divided into 24 hours. But the planet's highly elliptical orbit causes each Martian hour, minute and second to be nearly 3 percent longer than its counterpart on Earth. The result: A sol equals 24 hours and 39.5 minutes.

Allison has written a program called Mars24 that many JPL scientists and engineers will rely on to keep track of time. But that won't be the end of their worries.

JPL engineers will communicate with the rover through NASA's Deep Space Network, the global collection of giant antennae. The network operates on Coordinated Universal Time (colloquially known as Greenwich Mean Time). It is eight hours ahead of the Pacific time zone where the lab is located.

The arrival of NASA's second rover, Opportunity, on Jan. 24 could make life more confusing. Opportunity's landing site is on the opposite side of the planet from its twin - the time zone equivalent of a New York-to-Sydney flight. Some scientists and engineers will shuttle back and forth between the two missions.

"We'll all be feeling Martian jet lag," says Jim Bell, a Cornell University astronomer in charge of the panoramic cameras on both rovers.

To juggle so many odd work schedules, NASA acquired software originally designed to help hospitals manage the hectic, round-the-clock schedules of doctors and nurses.

Still, living out of sync with the rest of the planet's inhabitants is expected to take its toll. Just ask Joy Crisp, a JPL scientist who spent four weeks on Mars time during NASA's 1997 Pathfinder mission.

"After a month," she says, "we were pretty tired and cranky."

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