[meteorite-list] Decade-Old Rover Adventure Continues on Mars and Earth

[Ron Baalke]

http://www.jpl.nasa.gov/news/news.php?release=2014-002  

Decade-Old Rover Adventure Continues on Mars and Earth
Jet Propulsion Laboratory
January 03, 2014

Eighth graders didn't have Facebook or Twitter to share news back then,
in January 2004. Bekah Sosland, 14 at the time, learned about a NASA
rover landing on Mars when the bouncing-ball video on the next morning's
Channel One news in her Fredericksburg, Texas, classroom caught her eye.

"I wasn't particularly interested in space at the time," she recalled
last week inside the spacecraft operations facility where she now works
at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "I remember I
was talking with friends, and out of the corner of my eye I noticed this
thing bouncing and rolling on a red surface. I watched as it stopped and
opened up, and it had this rover inside."

That animation portrayed how NASA landed the Mars rovers Spirit and
Opportunity three weeks apart, using airbags to cushion the impact at
the start of the missions, planned to last for three months. Spirit
reached Mars on Jan. 4, 2004, Universal Time (Jan. 3, PST) and worked
for six years. Opportunity landed on Jan. 25, UT (Jan. 24, PST) and is
still exploring, with Sosland now on the team planning what it does each
day.

"I watched that news and said, 'This is amazing: a rover on another
planet!' Gears started turning in my head that day about engineering and
space -- thinking about a career. It was definitely a milestone in my
life and something I'll always remember."

On her path to that career, high-school teacher Brett Williams in
Fredericksburg inspired her to build real rockets, and she completed a
2013 engineering degree from the University of Texas, Austin. But nobody
in 2004 was predicting that either Spirit or Opportunity might still be
roving Mars in summer 2013, which is when Sosland joined JPL.

"I certainly never thought I'd have an opportunity to work on
Opportunity," she said. "That only became possible because this mission
has been going so incredibly long. The reason Opportunity has worked so
long is the people who built it and operate it. I'm loving that I can be
a part of this team now."

Most of the engineers who operated Spirit and Opportunity during the
three-month prime missions in 2004 have switched to other projects,
including later Mars spacecraft. Sosland is among several on
Opportunity's team today who were in school a decade ago.

Unlike her, Mike Seibert in late 2003 was eagerly tracking the run-up to
the rover landings, while he was an engineering undergraduate at the
University of Colorado. He had even ordered cardboard 3-D glasses in
anticipation of images from stereo cameras on Spirit and Opportunity.

"I was living in my fraternity's house in Boulder that January. People
thought I was weird, wearing 3-D glasses and looking at those pictures
from Mars," said Seibert.

Less than two years later, he was working on the rover team at JPL. He
has, since then, served as a mission manager and in other roles for both
Spirit and Opportunity and participated in many key moments of the
extended missions.

The dramatic landings and overland expeditions of Spirit and Opportunity
have also inspired countless students who have not gained a chance to
work on the rover team, but have participated in the adventure online by
exploring images from the rovers or other activities.

What an adventure it's been. Though Spirit and Opportunity were built as
nearly identical twins, and both succeeded in the main goal of finding
evidence for ancient watery environments on Mars, their stories diverged
early.

Spirit was sent to a crater where the basin's shape and apparent inflow
channels seen from orbit suggested a lake once existed. Opportunity's
landing area, almost exactly halfway around the planet, was selected
mainly on the basis of a water-clue mineral detected from orbit, rather
than landform shapes. Spirit's destination did not pan out initially.
The crater may have held a lake, but if there are any lakebed sediments,
they are thoroughly buried under later volcanic deposits. Opportunity,
the luckier twin, landed a stone's throw from an exposure of layered
rock that within weeks yielded compositional and textural evidence of a
water-rich ancient environment.

Within the initial three-month missions and without expectation of
surviving a full year, each rover set out cross-country toward other
destinations: hills on the horizon for Spirit and craters exposing
deeper layers for Opportunity. Spirit drove a total of 4.8 miles (7.7
kilometers), some of that with one of its six wheels not rotating. Loss
of use of a second wheel while the rover was in a sand trap contributed
to the 2010 end of that mission. Opportunity has driven 24 miles (38.7
kilometers) and is still going strong.

One key to Spirit and Opportunity working for years, instead of a few
months, has been winds that occasionally remove some of the dust
accumulating on solar panels that generate the rovers' electricity.
Also, the ground crew became adept at managing each rover's power
consumption and taking advantage of slopes for favorably tilting the
rovers toward the sun during Martian winters.

"Ultimately, it's not only how long the rovers work or how far they
drive that's most important, but how much exploration and scientific
discovery these missions have accomplished," said JPL's John Callas,
project manager for NASA's Mars Exploration Rover Project, who has
worked on the Spirit and Opportunity missions for more than 13 years.

By driving to outcrops miles from their landing sites, both rovers
reached evidence about multiple episodes of Martian history, "traveling
across time as well as across Martian terrain," he said. Opportunity is
currently exploring outcrops on the rim of Endeavour Crater, which is 14
miles (22 kilometers) in diameter.

"Opportunity is still in excellent health for a vehicle of its age,"
Callas said. "The biggest science may still be ahead of us, even after
10 years of exploration."

The science achievements have already provided major advances in
understanding of Mars.

The rovers' principal investigator, Steve Squyres of Cornell University,
Ithaca, N.Y., described some of the key findings, starting with what
Spirit found after driving from the crater floor where it landed into
hills to the east:

"In the Columbia Hills, we discovered compelling evidence of an ancient
Mars that was a hot, wet, violent place, with volcanic explosions,
hydrothermal activity, steam vents -- nothing like Mars today.

"At Opportunity's landing site, we found evidence of an early Mars that
had acidic groundwater that sometimes reached the surface and evaporated
away, leaving salts behind. It was an environment with liquid water, but
very different from the environment that Spirit told us about.

"When Opportunity got to the rim of Endeavour Crater, we began a whole
new mission. We found gypsum veins and a rich concentration of clay
minerals. The clay minerals tell us about water chemistry that was
neutral, instead of acidic -- more favorable for microbial life, if any
ever began on Mars."

"Because of the rovers' longevity, we essentially got four different
landing sites for the price of two."

The evidence the rovers glean from rocks at these sites may not be the
only huge benefit of the adventures, though. Bekah Sosland and Mike
Seibert may be examples of something even greater.

Squyres said, "I'm incredibly proud of the science we've done on this
mission, but in the end, perhaps our most important legacy will turn out
to be the young people who have seen what we've done and made career
choices based on that. If an outcome of our mission is to help inspire a
new generation of explorers to do even better than we did, that will be
the greatest thing we could have accomplished."

The Mars Exploration Rover Project is one strong element in a robust
program of NASA's ongoing and future Mars missions preparing for human
missions there by the 2030s.

The Mars Odyssey and Mars Reconnaissance Orbiter missions have been
studying the Red Planet since arriving there in 2001 and 2006,
respectively. NASA's next-generation Mars rover, Curiosity, is examining
an area that once offered conditions favorable for microbial life. NASA
launched the Mars Atmosphere and Volatile Evolution, or MAVEN, mission
two months ago, to begin orbiting in September 2013. The agency plans to
launch a mission to Mars in 2016 called Interior Exploration using
Seismic Investigations, Geodesy and Heat Transport, or InSight, to learn
about the deep interior of Mars. A Curiosity-size rover planned for
launch in 2020 has the task to check for evidence of past life on Mars.

Special products for the 10th anniversary of the twin rovers' landings,
including a gallery of selected images, are at
http://mars.nasa.gov/mer10/ .

JPL, a division of the California Institute of Technology in Pasadena,
manages the Mars Exploration Rover Project for NASA's Science Mission
Directorate, Washington. For more information about the project's twin
rovers, Spirit and Opportunity, visit http://www.nasa.gov/rovers and
http://marsrovers.jpl.nasa.gov . You can follow the project on Twitter
and on Facebook at: http://twitter.com/MarsRovers and
http://www.facebook.com/mars.rovers .

Guy Webster 818-354-6278
Jet Propulsion Laboratory, Pasadena, Calif.
guy.webster at jpl.nasa.gov

2014-002