Wearing two watches, one for Mars time on the left wrist and
one for Earth time on the right wrist, Jim Rice works in three
time zones on two different planets simultaneously. Jim is a
rover science team member with a Ph.D. in Astrogeology from
Arizona State University.

"Days of the week on Earth don’t matter anymore because
we’re living on Mars time with the rover twins," says Jim in
his strong Alabama accent. He beams: "Most of us on the
rover team are averaging about 4-5 hours of sleep a night. I
don’t know if it’s a.m. or p.m., but I’m loving every minute of

For at least the next three months, with all of his belongings
packed away in a storage unit in beautiful Scottsdale, Arizona,
Jim lives in corporate housing in Pasadena, California like
many of his fellow science team members from around the

"The furnished apartments are nice and a lot of great
restaurants are nearby, but I haven’t really had a chance to
check them out yet," Rice shrugs without much disappointment.
For the passionate scientists and engineers working on the
rover mission, digging into a hot dinner is not as exciting
as digging into the new data from Mars every day.

In the science operations area at the Jet Propulsion
Laboratory, the windows have been outfitted with special
black screens to prevent daylight from taunting any team
members into realizing their Mars night is really Earth’s day.
Scientists and engineers make every second of the mission
count by sticking to a fine-tuned schedule to ensure their

Shifting Schedules 40 Minutes Every Day

Mars rotates approximately 40 minutes slower than Earth
every day. Since each rover operates when the sun is pumping
energy onto its solar panels, the slower rotation of Mars boils
down to a longer day in which the mission team can use a
science instrument, drive a little farther, or send more data to

Thus, ambitious rover team members have chosen to extend
and alter their schedules 40 minutes every day to stay in sync
with their twins’ day and night schedules on Mars. One day,
for example, team members might come in to work at 9:00 a.m.
The next day, they’d come in at 9:40 a.m., and the next day at
10:20 a.m., and so on. They end up running multiple laps
around Earth’s 24-hour schedule throughout the mission.

Scientists and engineers utilize every possible second of
sunlight on Mars and squeeze in as much action as possible
with the rovers. To make life for the rover team ever more
fulfilling and confusing, Spirit and Opportunity live on opposite
sides of Mars. That means, when one rover is sleeping, the
other is awake, putting the rover team in business 24/7 – or

Like all good haggard parents with newborns, the rover team
does whatever it takes to listen to their twins’ calls around the
clock, provide them with the information they need to survive,
and steer them in the right direction during every waking moment.
The team has multiple shifts of people to cover the rovers ’round
the clock.

"Every day, all day, scientists and engineers are under pressure to
utilize finite energy resources as efficiently as possible to make
every single day of this 90 day mission as rich and fulfilled as
possible," explains Dr. John Callas, Mars Exploration Rover
Science Manager.

"We don’t want the rover just sitting on Mars in the daytime
twiddling its thumbs, so we assembled the best scientists from
around the globe to utilize their instincts in field geology and
remote sensing. Then we retrained them over the last two years to
be experts in seeing Mars through the eyes and instruments of the
rover," John recounts.

While the Rover is Sleeping

Multiple times every day, team members learn something new
about their location on Mars and they must quickly adapt their
priorities about what instruments they want to use or where
they want to drive. Decisions depend on what new information
they receive hour by hour.

"This mission is a new paradigm in robotic space exploration,"
John says with a smile. Scientists take in data sent directly to
Earth from the rovers and data collected through flyovers of
the Odyssey and Mars Global Surveyor orbiters, so they’re
getting new information to build upon three or four times a day.
"Historically, scientists could plan out in advance what they
wanted to do over the course of their mission, but we had to
create a highly trained, nimble team to do science quickly.

"Within only a few hours of nighttime on Mars, our team must
process several hundred images and other data that come down to
Earth in pieces at different times from different sources. We
turn the bits of data — zeros and ones — into higher level
products like mosaics and three-dimensional images almost
instantly, and then the scientists must assimilate all that
information to make educated decisions as to what to do next
with the rovers."

In general, the scientists prepare Spirit and Opportunity’s
"To Do" lists for the next day while the rover is sleeping on
Mars. Scientists use high-end workstations with extraordinary
visual graphic tools to interact with the data at a breakneck
speed. Individual scientists analyze the data as it comes down
and discuss their theories and insights with the six science
instrument teams and in five expert theme groups, which range
from "Soils" and "Mineralogy" groups to "Atmospheres" and

Rapid-fire Decisionmaking

After a few hours of interpreting the new data, proposing
science hypotheses, and attending context meetings about the
bigger, global picture of Mars, the entire team assigned to
Spirit or Opportunity gathers in the Science Downlink
Assessment room, which is packed with super-sized screens
that the whole team can see. These screens enable the team
to work together in discussing their initial analysis and results
of new data.

Over the hum of multiple high-end computers, team members
casually, but systematically, pass a microphone around the
room to the different team leads (for soil, atmosphere etc.).
Each is responsible for giving their team’s opinions and
recommendations for the full team’s consideration.

Immediately following a rover health status update from an
engineer, the various science instrument teams and theme
groups discuss their list of priorities and a path of possible
avenues in which to do the highest priority science next. Do
they want to stay and analyze a certain rock with a different
instrument or do they want to put the petal to the metal? Those
sorts of trade-offs to consider keep the meetings lively.

There’s literally no rest for the weary. Following the Downlink
Assessment meeting, the scientists swiftly reconvene into their
separate teams to come up with details on what activities they
want the rover to perform. Right after that, the smaller teams
join once again for the bigger two-hour Science Operations
Working Group (SOWG) meeting with the rover engineers. There
they tell the engineers what they would like to accomplish, and
hone their priorities into a well-choreographed, step-by-step
activity plan that will be built into commands. Science team
members must know how much power it takes to operate their
instrument and how much energy will be left to transmit data
results. Finding a balance is important because there are only
so many hours a day on Mars that the rover can do science and
can communicate with Earth.

Passing the Baton to the Engineers

It’s critical that all science priorities and negotiations of
power, energy, and time allocations are settled in time so the
engineers can create the commands and beam them up to the
rovers before the rovers start their days.

If the science team doesn’t complete their desired sequence of
events in time, the engineers can’t build the commands in time
and won’t be able to transmit new requests to the rover. In
that worst-case scenario, engineers would send up a
pre-canned sequence of science requests as a back-up, but
that’s not the best use of the rover.

Nobody Works an 8-hour day on Mars

The nap rooms that the management at JPL provides for the
scientists and engineers working on Mars time are rarely
used. "Mars is not the place to be if you want to work at a 9 to
5 job," Jim avows. "To be on this mission, you have to be kind
of nuts and have a passion and dedication for learning. My
work and my hobby are the same thing, and I’ve wanted to do
this since I was 7-years-old, so I enjoy working this hard. All
of our team members are cut from the same cloth."

NASA’s rover mission is filled with scientists and engineers
who are altering their natural circadian rhythms to live on
Mars time and sacrificing their dining desires, sleep, and
homes to work together as a team. Everyone from the security
guards to the engineers for the rover mission are on 12-hour
shifts, and the scientists tend to pore over new data hours
before and after their shifts officially begin and end.

"I think the desire to explore is encoded in human genes. We
are not the fastest runners or swimmers or strongest in the animal
kingdom, but our intelligence and curiosity allow us to be the
greatest explorers on and off the Earth," Jim expounds. "I’d wager
that every human being on Earth has looked up at the night sky
and wondered — at least once — what all those stars are about,
how we got on this Earth, or if we are alone in the universe."