Mars Rover Planners in Time Crunch to Prepare Spacecraft, Select Landing Sites

space.com ^ | 1/10/03 | Leonard Davis

[winner45]

	SEARCH:

advertisement

	Mars Rover Planners in Time Crunch to Prepare Spacecraft, Select Landing Sites By Leonard David Senior Space Writer posted: 09:30 am ET 10 January 2003

ARCADIA, Calif. -- Engineers and scientists working on the NASA Mars Exploration Rover (MER) project are in the final stages of readying the twin robots for launch and picking safe and scientifically rewarding landing sites on the red planet.

The road to Mars for the MER program has not been easy. A number of technical challenges -- such as designing, testing and qualifying airbag and parachute systems, in particular -- dogged the project, requiring extra time, money and talent.

Meanwhile, during the past two years, Mars scientists have mulled over some 185 landing sites. They have debated the merits of each, and continue to wrestle with a matrix of maddening worries -- from high winds, dust, swings of day/night temperatures to dangerous rocks that might cripple chances for successfully landing and operating the robots.

Images

A simulated image of the new Mars rover carrying the Athena science instruments.

A MER robot meets smaller Sojourner test rover, identical to the Mars machinery that rolled its way across the red planet in 1997.

Checkout tests are underway on the Mars Exploration Rover 2, destined for red planet duty in early 2004.

More Stories

	Twin Mars Rovers: Planning for a Safe Landing

	NASA 'Cautiously Optimistic' Mars Rovers Will Be Ready For Launch

	Scientists Test New Mars Rovers for Upcoming Mission

	IBM's BlueBoard Technology on the Red Planet

	Mars Rover Landing Spots - Blowing In The Wind

Multimedia

Related Links

	JPL's Mars Polar Lander Homepage

	Robotic Outposts a Necessary Next Step in Exploring Other Worlds

	Mars on Earth: A Four-Part Series

	Mars Odyssey Orbiter: The 2001 Mission to Mars

	The Red Planet: Basic Reference

At the 4th 2003 Mars Exploration Rover Landing Site Selection Workshop being held here this week, hardware and high hopes are on the table as the countdown to launch draws inexorably closer.

First and foremost

Where on Mars the robots will bounce to full stop still is under discussion.

Four landing locales have been culled from a huge list of promising sites. They are Terra Meridiani, often called the Hematite site (and soon to be named Meridiani Planum), Gusev Crater, Isidis Basin and a "wind safe" site in Elysium.

Each has its merits. Each has its drawbacks.

"First and foremost, of course, is the fact that if you don't land safely you don't get any science back," said John Grant, co-chair of the Landing Site Steering Committee. Grant is based at the Smithsonian Institution's Center for Earth and Planetary Studies at the National Air and Space Museum in Washington, D.C.

"The sites that we're looking at now are undoubtedly the best studied locations on the surface of Mars, I would argue," Grant said.

Furthermore, those landing spots were whittled down on the basis of science, said Matt Golombek, also a co-chair of the Landing Site Steering Committee, based at the Jet Propulsion Laboratory (JPL) in neighboring Pasadena, Calif.

"This is in fact the first time that site selection has used science to triage landing sites on Mars," Golombek said.

Picking the right site

Those landing locations are on the table because they address the science objectives of the rover missions: Determine if water was present on Mars and whether there are conditions favorable to the preservation of evidence for ancient life

Elysium likely contains ancient terrain, which may hold clues to Mars' early climate when conditions may have been wetter. The three other sites show evidence for surface processes involving water.

Each wheeled rover carries the Athena package of science gear. That array of equipment has undergone rigorous calibration and testing, said Steve Squyres, principal investigator for the science payload at Cornell University in Ithaca, New York.

Matching Athena's performance to the right site to maximize scientific output and achieve testing of scientific hypotheses is crucial.

"What you do here not only benefits the selection process, but it will directly impact operation of the rovers," Squyres told the gathered group of scientists. "We've got to run the last lap of this race…and getting the details right is essential," he said.

Deliberations regarding the sites are keyed to hammering out final landing area recommendations to be given to NASA space science chief, Edward Weiler. He will make the final determination of MER landing sites in early April.

Ship and shoot

It is clear that time is short at hand.

The launch window for the first rover opens May 30, 2003, and the second rover's launch period begins June 25, 2003. Touchdown of the first rover on Mars is Jan. 4, 2004, followed by the second robot arriving on Jan. 25, 2004.

Each rover will have a primary mission lasting at least three months on the martian surface.

Phased shipping of mission hardware to the launch site in Florida begins this month, said JPL's Rob Manning, the MER Entry, Descent and Landing Operations Manager.

Manning served similar duty for the Mars Pathfinder/Sojourner rover mission that touched down on the red planet in July 1997.

"For MER, 2002 was a very, very intense year," Manning told SPACE.com. "The project was less than three years from start to launch. We had to do so much over again. So many parts of the system we had to go back and reengineer for this larger mass vehicle."

"We did far more testing on this project than we did on Pathfinder...and we thought we did a lot then," Manning said.

Bounce to the ounce

For instance, the huge gaggle of airbags that cocoons each rover during hard landing has been drop tested some 50 times. Early tests proved worrisome. So much so that significant beefing up of the airbags was necessary.

Similarly, there were a number of ill-fated tests of the MER parachute system. That too demanded considerable extra work to iron out a mission trouble spot.

What are the drivers for mission success?

"Very simply it's how fast you hit, what you hit, how you bounce, and how long you live after you survive all of that," said Mark Adler, JPL's Project Landing Site Engineer for MER.

"The first bounce isn't the last bounce. This is a very robust system. But there is one annoying feature. It lands more than once. And in fact, it lands many times," Adler said.

Mother Nature's artifacts

For Jim Garvin, NASA Lead Scientist for Mars Exploration, MER is the first real taste of the surface. The twin rovers armed with the Athena science payload will calibrate the whole community on what Mars is truly like.

"I like to call rocks 'Mother Nature's artifacts.' They hold the stories. They don't lie. But you've got to get to them. Until we get to those rocks and train people to understand them and move amidst them... touch them and taste them... coupled to the remote sensing as to what is really happening on the surface of Mars, well, it is always going to be a bit of a crap shoot. We get it wrong even here on Earth."

Given the two Viking landers and Mars Pathfinder/Sojourner, scientists know a little about three spots on Mars.

"And we're still confused about those," he added.

"I think what MER will give us is far less confusion about two very different types of sites. MER can't miss if it lands and its great instruments get to touch anything."

     about us | message boards | register at SPACE.com | contact us | advertise | terms of service | privacy statement

     © 1999-2003 SPACE.com, Inc. ALL RIGHTS RESERVED.

[winner45]

We'll get to Mars when we get there.

[Mo1]

PLEASE SUPPORT FREE REPUBLIC

Donate Here By Secure Server

Or mail checks to
FreeRepublic , LLC
PO BOX 9771
FRESNO, CA 93794
or you can use
PayPal at Jimrob@psnw.com

Become A Monthly Donor
STOP BY AND BUMP THE FUNDRAISER THREAD

[RightWhale]

They need to choose a site. Let the people choose. DA PEOPLE. 10 to 1 it would be Cydonia.

[ASA Vet]

They should choose LZ's out of range of Barsoom SAM sites this time.

[anymouse]

BTW, the author's name is Leonard David, not Davis.