[meteorite-list] Landing Sites Debated for Next Mars Rover

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Wed May 31 16:47:44 2006
Message-ID: <200605311629.JAA14853_at_zagami.jpl.nasa.gov>

http://www.space.com/news/060531_msl_destination.html

Landing Sites Debated for Next Mars Rover
By Leonard David
space.com
31 May 2006

PASADENA, California - When NASA's next wheeled robot - the Mars Science
Laboratory - rockets skyward in 2009, the mega-rover will carry the
largest, most sophisticated array of science gear ever shot to the
martian surface.

Far more robust and powerful than those smaller robotic look-alikes now
laboring on Mars - Spirit and Opportunity - the Mars Science Laboratory
(MSL) is intended to turn a new page in planetary exploration.

But here's the issue at hand: Where to land the hunk of high-tech
machinery; deciding the ideal spot that's safe but also maximizes the
rover's chances to help figure out if Mars ever was - or is today - an
abode for life.

Leading Mars investigators and space engineers are gathered here this
week at the first landing site workshop for the 2009 Mars Science
Laboratory.

First cut

The purpose of the workshop is to hear about all of the proposed MSL
landing sites...and to make a first cut at prioritizing them, said John
Grant, a geologist at the Center for Earth and Planetary Studies at the
National Air and Space Museum in Washington, D.C.

Grant also co-chairs the MSL landing site steering committee that
organized this week's meeting.

"All of the sites will probably remain under consideration after this
first workshop, but they will be prioritized into high, medium, and low
groups," Grant said. A key job of workshop participants is to help in
this categorization; a task that then assists in targeting the various
prospective landing sites by the fleet of probes now orbiting the red
planet - particularly NASA's new arrival, the Mars Reconnaissance
Orbiter.

As part of this week's intensive workshop, MSL engineers will advise the
gathered scientists about restrictions and limitations in landing and
running the large rover on Mars.

"Engineering constraints are critical - because if the rover does not
land safely you don't get any science," Grant advised. "And once the
rover lands, the rover needs to be able to move around."

Latitudes and attitudes

Grant said that the current site constraints are very broad and allow
consideration of sites at a range of elevations and latitudes not
considered by Spirit and Opportunity Mars rover planners, for example.

Also, the science constraints for MSL are pretty clearly spelled out.

"Obviously, the more and higher priority relevant science targets a site
possesses, the higher it may be ranked. It may require additional
data -such as from the Mars Reconnaissance Orbiter - to assess what
engineering risks and science potential the various proposed sites
have," Grant told SPACE.com. Hence, the desire to rank sites high,
medium, low at this first workshop.

It's already clear that where MSL could be targeted stirs up healthy
debate and competition between Mars experts.

Some scientists here are backing the Holden Crater region. Others
suggest that Gale Crater is a feature likely to rise to the top of the
must do list. Many point to a "no brainer" of an exploration hot
spot - the huge canyon landscape of Valles Marineris.

"Valles Marineris looks good now...but remember the cold feet that the
engineers got about this with Spirit and Opportunity. I wouldn't be
surprised if Valles Marineris eventually falls out of favor for
engineering reasons," predicted one Mars researcher taking part in the
workshop.

Finding the right balance

For sure, getting a rover on the red planet isn't a walk in the park - in
terms of where to land and other judgments necessary. Just ask somebody
that's gone the distance.

"One of the hardest things about picking a landing site is finding the
appropriate times to make decisions," said Steve Squyres, lead scientist
from Cornell University for the Spirit and Opportunity rovers already
wheeling about Mars.

"From an engineering perspective, you want to make the decision as soon
as possible. The sooner you know where you're going - at least in general
terms, like latitude and altitude - the easier it is to come up with a
spacecraft and mission design that'll perform well under those
particular conditions," Squyres told SPACE.com in an earlier interview.

However, from a science perspective, Squyres noted, you want to make the
decision pretty late in the process.

"Orbiters overhead are always collecting more data and scientists are
always looking at the data...so the longer you wait, the more you know.
We worked hard to find the right balance...and Mars Science Laboratory
is dealing with the same issues."

Science payload progressing

Winds, rocks, the slopes of terrain are part of the appraisal of where
best to put Mars Science Laboratory down on the planet, said Richard
Cook, MSL Project Manager here at the Jet Propulsion Laboratory (JPL).

Not only is the new and powerful Mars Reconnaissance Orbiter (MRO) to be
used to help certify an MSL landing zone. "It's also possible that MRO
will see something particularly interesting that will add sites to the
candidate set," Cook explained.

Cook told SPACE.com that the science tools MSL will tote is coming
together. "The payload is sort of out in front of the rest of the
project," Cook said. "We're far from out of the woods - but things seem to
be progressing along in a pretty good way."

At this stage, both the MSL design and which landing site may be of
interest are maturing at the same time, Cook said. "If we were going to
pick a landing site right now, I'd be a little more concerned. The
engineering assessment [for MSL] may evolve over time."

Holy Grail: a habitable environment

Cook said that the "on-paper process" calls for an MSL landing site to
be chosen a year before the rover's launch in the fall of 2009. "Unless
something happens to change that, that's what we'll do."

The MSL mission, including cost of a launcher, is about $1.5 billion,
Cook said. A decision on what booster will hurl the rover long range to
Mars is near at hand, he said.

Once on Mars, the large nuclear-powered rover is to assess whether Mars
ever was, or is now, a world that supports microbial life - a mission to
determine the planet's habitability.

"That's the Holy Grail of what we're trying to do," Cook said, to find a
site that optimizes the chance of proving that it's a habitable
environment. "That's what the scientists have to wrestle with...and
there's a diversity of opinion about how to improve the chances of
finding what we're looking for."
Received on Wed 31 May 2006 12:29:42 PM PDT