Morten Bo
Madsen spends his work day crunching data on a laptop seated in front of a clear
plastic-covered box about the size of a widescreen computer monitor that emits
a startlingly bright blue light.
No, this
isn't a scene from a sci-fi movie. Madsen is one of the 150 scientists and
engineers working on NASA's Phoenix
Mars Lander mission. The bright light keeps Madsen's internal clock in
check, because Madsen, you see, is living on Mars time.
Phoenix is a $420 million mission with the
aim of sampling and analyzing the dirt and subsurface ice layer in the north
polar regions of Mars as it looks for signs that the red planet may have been
habitable at some point in the past.
Since the
spacecraft landed on Mars on May 25, mission controllers have been living on
its schedule, or rather the exact opposite of it. When the spacecraft is
sleeping during the Martian night, the scientists are up analyzing data; when
the spacecraft rises at the beginning of the day on Mars, they retire and let Phoenix do its work.
This may
not sound like too taxing a schedule, but there are a couple of catches: Mars'
day is 40 minutes longer than Earth's, and the start of the Martian day is
always changing with respect to Earth time, as a result of their respective
orbital motions.
Living on a
schedule that shifts forward by 40 minutes everyday can wreak havoc on the
human body, creating an effect that is essentially like perpetual jet
lag.
"It
would be like traveling two time zones every three days," said
physiologist Laura Barger of Harvard Medical School and Brigham and Women's
Hospital in Boston.
Barger and
her colleagues are studying Madsen and 18 other Phoenix team members as they
try to adapt to their Martian schedule, monitoring them for signs of fatigue as
well as providing tips for how to live out-of-sync with the rest of the world.
The results could help guide future space travelers and Mars missions.
Studying
Mars time
All humans
possess an internal
"circadian" clock that runs on a roughly 24-hour cycle, modulated
by the daily shifts between light and dark as the Earth rotates.
"We
know that light is the most important time cue to the circadian clock,"
because it tells the brain what time of day it is and what the body should be
doing, Barger said.
Anyone who
has flown between time zones knows that the abrupt shift in the time of day can
throw sleeping and eating schedules out of whack. The same came happen to swing
and night shift workers.
Living on
Mars time can create the same issues, because "you have sort of a rotating
shift with the Martian day put on top of it," as Barger describes it.
"We
knew from our laboratory work when we simulate people living on a Martian day
that they have misaligned circadian rhythms," she said. "They're not
able to adjust. They have problems sleeping."
NASA
officials and researchers were aware of the difficulties that the teams for 1997's
Pathfinder mission and the 2003 Mars Exploration Rover missions had when they
tried living on Mars time. Phoenix principal investigator Peter Smith spoke
with one of Barger's colleagues about coming to help his scientists adjust to
their demanding schedule, and NASA agreed to fund the study.
Live
tests
Barger and
her team are intensely monitoring and working with the Phoenix team members in Tucson, Ariz.,, who all volunteered for the study. The medical team is providing the Phoenix crew with ways to adjust to their extreme schedule (Madsen's blue light box, for
example), as well as tracking the effects that living on Mars time has on them.
Each study
participant wears an "actigraph" watch that monitors his or her motion
(people move less when they sleep) as well as their exposure to light, that
essential circadian cue. They also complete computer game-like reaction time
tests before and after each shift. They use a scale on a computer to describe
their mood (tired people can often be grumpy) and to test their memory while
they're on duty. The Harvard team is also measuring levels of a metabolite of
melatonin in samples of participants' urine.
Because
melatonin responds directly to the circadian clock, measuring its levels
"tells us what time the clock is on, if you will," Barger explained,
letting the researchers know whether or not the Phoenix team members were
adjusting to their schedule.
The light
boxes given to the participants help regulate their circadian clocks, giving
them the light
cues they miss on their shifting schedule.
"Normally
when you're just living here on Earth, you have a 24-hour light-dark cycle, and
your clock gets reset every day," Barger explained. "When you are
living on a Mars day, your clock would have to be lengthened every day by about
a half hour. We know that bright light [particularly at the blue end of
the spectrum] in the evening will help lengthen the day, so we've given them
this light box."
The Harvard
team is also providing Phoenix crew members with simple tips for dealing with
fatigue, including drinking small cups of coffee throughout the day, instead of
a Venti mocha right before their shift; taking naps if their head starts
bobbing at the computer; getting a full night's sleep and staying on Mars time
even on days off.
How to
live on Mars time
Madsen, a
scientist from the University of Copenhagen who works with the lander's robotic
arm camera, says Mars time actually hasn't been too hard for him. As one of six
Danes temporarily living and working together while they're in Tucson for Phoenix's three-month
primary mission, he says the camaraderie has helped him deal with the
continually shifting schedule.
"We
try to live like a family, and get up together in the morning, have breakfast
together. And we keep each other on a tight schedule," he told SPACE.com.
Troy
Hudson, a NASA Jet Propulsion Laboratory engineer with the lander's Microscopy,
Electrochemistry and Conductivity Analyzer, has also had little trouble keeping
on Mars time, clearly reveling in the experience.
"Personally,
I rather enjoyed living on a Mars schedule, both for its, just, fundamental
unusualness, and of course it has made working with the spacecraft easy,"
he said, though maintaining his pre-work gym routine when he was waking up at 2
a.m. was a challenge.
Hudson, who
is applying to be an astronaut, said that sitting in front of one of the
brilliant blue LED light boxes took some getting used to, though he grew
accustomed to it within a week or two.
Madsen
agreed. Even though everyone walks around with a bloodless pallor, he thinks
that "it's doing its job producing something that is similar, more or less
similar to daylight, which helps us staying awake."
Not
everyone has found the experience as easy as Madsen and Hudson.
Night
owls vs. early risers
Deborah
Bass, a project scientist on the mission, says that the shift work can be
harder for early risers like her than for night owls. "I like mornings. So
doing this night work for me is extremely difficult," she said, adding:
"I also really thrive on routine. So for me, this is also exceptionally
challenging."
Madsen did
note that sometimes he didn't sleep through the night and would be tired the
next day at work. In these cases he would take a brief snooze in nap rooms
provided to the scientists. "Just 10-20 minutes, you're just as new
again," he said. Hudson has never used the nap rooms, he said, though he
acknowledged that "occasionally I have felt that tired."
Bass also
lived on Mars time during the MER
primary missions and monitored the effects of the schedule on the MER team
for NASA, and said that the Phoenix team is experiencing some of the same
difficulties.
For people
who live in Tucson, where mission operations are based, the stress of living on
Mars time can actually be greater because staffers try to interact with their
families on their days off. They may try to switch back-and-forth from Mars
time, making the adjustment for their body harder. If they stayed on Mars time,
they wouldn't be able to interact with their families as much. Crew members
coming from other institutions and living temporarily in Tucson don't have the
same pressure to interact with their families, Bass said.
Madsen and
his Danish colleagues, for example, mostly email with their families, only
seeing them on week-long trips back to Denmark — switching back to Earth time
is a little easier for longer periods like this, they said.
Social
life suffers
Bass and
other mission scientists also said that it was difficult to interact with
society on the rotating Mars schedule — the options for socializing are slim if
you're getting off of work at 3 or 4 a.m. Errands and laundry can't be done in
the middle of the night either.
"So
even on your days off, you may not be really getting absorbed back into your
normal life," Bass said. "Life is hard to maintain."
Along those
lines, Madsen told a story of an encounter during an early morning hiking trip
with his colleagues that shows the disconnect the scientists can feel with the
outside world. Some passing hikers on the trail said, "Good morning."
Madsen and his companions had to stop and think for a moment before replying "Good
morning," because to them, it was almost bed-time.
On the
whole, Bass said that the reaction to living on Mars time is "very
individually driven." Some, like Hudson, thrived on the schedule; others,
like Bass, have struggled with it (Bass says the experience has given her more
appreciation for the schedule her husband works as an ER doctor).
Overall
though, Bass thinks the team is doing well and credits their drive and passion
for the mission, a once-in-a-career opportunity for many of them, for much of
this.
"The
team is extremely dedicated; the team has no intention of letting up, and they
absolutely, again, they feel extremely privileged to have this opportunity to
work on this Mars lander," she said.
Madsen
agreed that the focus on the mission helped the team to almost ignore the
Earth-bound schedule of the city around them. "We live kind of in our own
world, because everything that is important to us takes place on Mars," he
said.
Earth-bound
again
Even those
who have thrived on the Martian schedule must eventually come back down to
Earth. The fatigue shown by the members of the Pathfinder and MER missions at
the end of a few months shows that "the team [only] seems to be able to do
this for a limited period of time," Bass said.
"I
think that in the beginning, right after landing, the enthusiasm was at an
absolutely fever pitch. Adrenaline was coursing through the team for quite a
bit of time," as the first images came in and the components of the lander
were moved for the first time, she added.
But
eventually as the weeks wear on, and the mission moves forward, "there are
less dramatic surprises, and less anticipation of a particular event," Hudson said. The number of applause-worthy events starts to become more spaced out.
Eventually,
"one realizes that this is also one's life, that one needs to be able to
sleep and eat and interact with family," Bass said.
Phoenix's primary mission comes to a close at
the end of August, and the team was set to return to Earth time for any
possible extended
mission. They'll actually make the switch earlier than expected, on Aug. 1.
The decision
to switch earlier was made because right now the team's Mars time schedule
coincides with local daytime, making the switch easier, according to Phoenix robotic arm co-investigator Ray Arvidson of Washington University in St. Louis. The team has become efficient enough now to make command decisions during the
day, regardless of what time it is for the Phoenix lander, he added.
Barger
plans to publish results from her data collected during the two months that the
Phoenix team has lived on Mars time sometime in 2009, and says they could
help inform whether future
missions will live on Mars time.
However, as
the switch date draws near, neither Madsen nor Hudson is concerned about coming
back down to Earth.
Hudson said he wouldn't mind staying on
Mars time for longer, but that it will be nice to have the chance to hang out
with friends who live in Tucson without first having to check and see if he'll
be asleep.
Madsen
agreed: "I don't think [living on Mars time] has been a big deal, but in a
way it's nice to know that when you are [on Earth time], to know that you'll be
on the schedule of Tucson local," he said. The switch back will be
especially nice for him, he added, as he will be taking two weeks off to
explore the area when his wife comes to visit, since he has mostly only seen Tucson and the mountains that surround it in the middle of the night.
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