[meteorite-list] Specialists at NASA Spar On Where Mars Rover Should Go

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu Apr 22 10:32:05 2004
Message-ID: <200401211746.JAA11574_at_zagami.jpl.nasa.gov>

http://www.boston.com/news/nation/articles/2004/01/21/specialists_at_nasa_spar_on_where_mars_rover_should_go/

Specialists at NASA spar on where Mars rover should go
By Beth Daley
The Boston Globe
January 21, 2004

PASADENA, Calif. -- The room went wild when Spirit hit the Martian dirt.
With six wheels on the blush-colored surface Thursday morning, scientists at
mission control here traded high fives and hugs.

But there was still trouble ahead: No one could agree where it should go
next.

Chief scientist Steve Squyres wanted the rover to investigate a
pyramid-shaped rock nearby. Some geologists had their hearts set on a
far-off crater. And the mission's engineers wanted the rover to stay put so
they could test its instruments for three days.

After three painstaking years of building, launching, and precisely landing
the spacecraft in Gusev Crater, the rest of the $410 million rover's
itinerary is a blank page. And with Spirit's life span expected to be just a
few months, each decision is loaded with urgency.

"Where we are going is a fundamental question, and it can get emotional,"
said John Grotzinger, 46, an MIT sedimentologist helping to figure out where
the rover should go.

In NASA's ambitious new quest to find signs of past water on the Red Planet,
control of the vehicle now largely rests with a 50-member science team at
the Jet Propulsion Laboratory. The team includes geologists, soil analysts,
and others -- each of them a specialist who sees Spirit as key to unlocking
a different part of the Mars mystery.

To create a kind of road map for the mission, Grotzinger helps lead a small
group of a half-dozen scientists who try to lay out agendas for the rover.
They meet at the start of every Martian day and work in shifts of 12 hours
or longer, fueled by coffee and a huge supply of free ice cream.

On Thursday, it was midnight in California when they gathered under a red
sign marked "Long-Term Planning." As data streamed in, scientists approached
the group's members to debate the merits of possible sites.

Their immediate goal was to ensure that the Spirit is visiting the most
interesting rocks and patches of soil in its quest for signs of water. But
larger questions loomed: Should the rover spend its limited time exploring
one small swath of Mars? Or should it push toward the hills more than a mile
away in hopes of seeing something unexpected?

"At the end, you go with the best available science," Grotzinger said.

The National Aeronautics and Space Administration has established a few
rules of the road. Spirit should travel at least 1,000 feet during its
mission. It should visit at least four "localities," although scientists
aren't exactly sure what constitutes a locality. It should use its
instruments, including cameras and spectrometers that can identify elements
in rocks and soil, as well as a rock abrasion tool.

But those guidelines leave most of the mission up in the air. Going to a
distant cluster of rocks may reveal round boulders put there by rivers.
Checking out the lip of a crater may show layers of sediment that could
point to liquid water. And in the simplest nearby rocks, minerals could show
they were formed in the presence of water.

Once Spirit landed safely on Mars, the scientists began to argue about what
to do if it survived the short drive off its lander. Should it go to a
nearby depression dubbed Sleepy Hollow?

Engineers did not want Spirit to move while they tested out its instruments.
But this idea ate at the other scientists: By remaining in place, Spirit
would be restricting itself to an area that was both dirtlike and pebbly.
That mixture, at least for a first experiment, would yield confusing
information.

Earlier in the week, when Spirit was still on the platform, Rob Sullivan, a
Cornell planetary geologist, made a persuasive plea to the full science team
to send Spirit to a rock first.

"I see every day costing $4.5 million," he said later. "And what science do
we get?"

The clash of agendas is familiar in fields such as planetary science, in
which researchers wait years for the results of a tiny number of high-priced
missions. Space telescopes inspire the same jostling for time as do deep-sea
submersibles and particle accelerators.

But the eyes of the world are on this rover the size of a golf cart. At
best, it could last six to nine months before Martian dust covers its solar
panels, and at worst it could suddenly succumb.

In a week,Spirit needs to be someplace scientifically interesting,
Grotzinger said. That's when its twin spacecraft, Opportunity, is supposed
to touch down on the other side of the planet. Many scientists will be
involved in that landing and may need to leave Spirit in place for three
days. As each option is aired, the long-term group creates decision trees on
a giant computer board. Among others, the tree answers one pressing
question: If we move the rover here, where could it end up for its three-day
visit?

"It's like a chess game," said David DesMarais, who heads the long-term
group with Grotzinger. "How do you optimize the number of moves on Mars?"

On Jan. 13, after Sullivan made his case to the science team to go to a
rock, the opinions among the mission's scientists shifted. They began to
favor two rocks about 8 feet away from where the rover planted itself, one
named "sushi" because of its shape, and the other called "sashimi."

But engineers balked again the next night. The two rocks might be too close
to each other to poke the robotic arm into the soil safely.

By Thursday morning, as Spirit crept off the lander, Grotzinger and other
scientists were in mission control considering a pyramid-shaped rock about
11 feet away for the rover's first visit. The football-sized rock had a wide
side surface that Spirit's grinder could work on.

Less than an hour later, Grotzinger addressed the science meeting, letting
team members know about the new rock. He checked the Internet for a name
better than "Pyramid," and he settled on "Adirondack."

Thirty minutes after that, Squyres burst into the room. No more discussion:
Engineers were going to do their tests right where the rover was sitting.
The rocks would have to wait. A few clear patches of sand were found so
scientists might get clean data.

As soon as he left, Grotzinger and the entire science team began
prioritizing what rock they should go to after the tests were completed. By
Saturday it was settled: Once Spirit began rolling again, it would visit
Adirondack. Not only will the rover be able to spend three days at the rock,
possibly boring into it, but it could get to Sleepy Hollow by the time
Opportunity lands.

Yesterday the rover examined the rock.

On an alien planet, "you can't help but discover something," said Maria
Zuber, head of MIT's Department of Earth, Atmospheric, and Planetary
Sciences who consults at the Jet Propulsion Laboratory. "The remarkable
thing about this is, it's discovery in its purest form."

Beth Daley can be reached at bdaley_at_globe.com.
Received on Wed 21 Jan 2004 12:46:00 PM PST