Why Mars mission scientists will have breakfast at 10 p.m.

Researchers working in the MarsLab in the Space Sciences Building on campus aren't living on Mars time, as are some of their colleagues at the Jet Propulsion Laboratory in Pasadena, Calif. However members of the Cornell Calibration Crew in the MarsLab, including graduate student Eldar Noe, left, and research support specialist Pam Smith, must be constantly aware of the 12 hours separating the locations of the two Mars rovers and the time differences between Mars and Earth. Behind Noe is a screen showing Mars time for the rover Spirit, and the screen behind Smith shows the time for the rover Opportunity. Frank DiMeo/University Photography

By Kate Becker

Cornell astronomy researcher Diane Bollen calls it "dream science" -- the rush of excitement as data pours in, fresh hypotheses are put to the test and new discoveries blossom. But she could just as easily mean science that happens when the rest of the world is dreaming.

Since the twin Mars rovers Spirit and Opportunity bounced down in January, Cornell scientists at NASA's Jet Propulsion Laboratory (JPL) in Pasadena have been keeping "Mars time," rising, as the sun does on Mars, 39 minutes and 35 seconds later each Earth day.

Thirty-nine minutes might not seem like much, but over the course of just two weeks, the scientists must adjust the time at which they wake by an accumulated nine hours. If they woke up at 8 a.m. on St. Patrick's day, by today (April 8), breakfast time will be at 10 p.m.

About 30 members of the rover team have been outfitted with small wristwatch-like accelerometers that record the motions of the wearers. From this record, sleep researchers at NASA Ames Research Center are analyzing how living on Mars time affects the researchers' sleep-wake patterns.

Sleeping in later every day isn't a problem, said Jascha Sohl-Dickstein, a research support specialist with the mission. "It's much gentler on me when I stay up too late." The bigger problem is deflecting visual cues from the 24-hour world, he said. "When I drive home from work at the end of a long day, and the sun is just starting to come up, it's really painful."

To preserve their time-zone microcosm, visiting scientists at JPL have blackout shades in their rented apartments and ensure that the housekeeping staff comes by when they are away working, not home sleeping. Some on the team wear special "Mars time" watches, Seikos and Citizens converted by a watchmaker in nearby Montrose, Calif.

"There were occasional strange looks and conversations with waiters and waitresses when we came in at eight in the morning and ordered dinner and beer," Sohl-Dickstein recalled. "A lot of the summer camp ... feel has faded by now," he admitted.

"Living on Mars time itself is not difficult," said Bollen. The unusual schedule is hardest, she noted, on engineers who work full time at JPL and live with their families in Pasadena. "The key to living on Mars time," she said, "is to stay on Mars time." Exposed to the normal rhythms of their families' school and work days, the engineers find it challenging to stick to the Mars schedule. "It wears on you," she said.

A typical day for the Spirit team begins around 8 a.m. local Mars time, said Cornell's Jonathan Joseph, software development leader for the panoramic cameras that are on board each rover. For the next 12 hours, scientists pore over data transmitted by the rover and set its priorities for the next day. As these scientists head home, the "night shift" comes on to sequence the instructions they will later send to the rover. A color-coded calendar grids the teams' shifts in a drifting patchwork of purple, yellow and green.

Complicating matters is the fact that Opportunity's landing site on Meridiani Planum is halfway around the planet from Spirit's location in Gusev crater, meaning that the sun rises about 12 hours earlier for Opportunity than it does for Spirit. Separate teams are assigned to each rover, with the Opportunity team waking up 12 hours earlier than Spirit and its team.

Sohl-Dickstein uses the term "staircase fatigue" to describe the "jet lag" that accompanies a trip from the fourth floor of JPL, where Spirit's team works, to Opportunity's labs on the fifth floor. When it is noon on the fourth floor, it's midnight on the fifth.

The two teams' days on Mars time are numbered, though. During April the teams will be switching back to Earth time. "Now that we've got the hang of things," said Bollen, the tightly kept Mars time vigil is no longer necessary. During April many of the Cornell scientists will pack up and head for the 24-hour comfort of Ithaca. Working in the MarsLab in the university's Space Sciences Building, they will continue to squeeze as many days of work as they can out of the rovers. Though the nominal mission end date was April 6, the rovers could well have enough power to keep running well into the summer and beyond.