Opportunity to Roll Onto Mars Surface Saturday

By Leonard David
Senior Space Writer, SPACE.com

UPDATE: Story first posted 11:50 a.m., January 30, 2004

PASADENA, Calif. -- Engineers have moved forward plans to unleash Opportunity from a parked position atop its lander, then roll off onto Mars surface in Meridiani Planum early tomorrow morning.

Scientists here at the Jet Propulsion Laboratory (JPL) are hungrily awaiting the output from new scans of martian real estate and a rock outcrop at Opportunity's home within a small crater.

Opportunity's lander platform successfully tilted itself forward by pulling airbag material under the rear portion of the lander then flexing its rear petal downward. The result: The tips of a reinforced fabric off-ramp for the rover are now in the soil. This means Opportunity can be commanded to perform a simple, straight-ahead drive-off.

The rover's six wheels have been positioned to start driving duties. Getting Opportunity's wheels down and dirty on Mars is now slated for early Saturday.

From a distance

From the deck of the lander, Opportunity did use its Mini-Thermal Emission Spectrometer (Mini-TES), scanning a slice of the neighborhood terrain, including the rock outcrop. Mini-TES identifies the composition of rocks and soils from a distance.

Word is that new science results from Mini-TES clearly identify hematite within Opportunity's landing area. But at an early morning press briefing here today, scientists would not confirm or deny that significant finding.

Scientists have become increasingly skittish of getting caught in "instant science" pronouncements, mainly for fear of being proven wrong in hours or days based on new observations.

Hematite: window into the past

Hematite is made up of iron and oxygen -- a type of iron oxide. Deposits of grey hematite are usually found in locales in which standing water or mineral hot springs have been present. But hematite can also occur without water, as a product of volcanic activity.

Along with that hematite, other materials would offer more clues as to Meridiani Planum's geological past. For example, clays and carbonates would indicate there had been water in the area. If the area had been volcanic, other types of minerals, such as olivine and pyroxene would be present.

Water-related hematite would help shore up the prospect that life may have existed on Mars.

Intriguing variations

The new Mini-TES data shows "intriguing variations" from place to place, said Ray Arvidson, Deputy Principal Investigator for the MER program from the Washington University in St. Louis. Opportunity scientists are still in the process of looking at the data.

Arvidson balked at revealing what the Mini-TES has found, but called it "beautiful data". Rather, he said the instrument is a very complex instrument and the spectra it produces are difficult to interpret.

"But if you look at anybody on the Mini-TES team, they have huge smiles on their face," Arvidson coyly told SPACE.com . Because the information is new, they want time to check and double-check before they make an announcement, he added.

High discovery potential

"We just totally lucked out by landing in this little crater," Arvidson said. That crater is 72 feet (22 meters) wide and 10 feet (3 meters) deep.

The exposed outcrop of rocks is ideal for exploration by Opportunity.

"That outcrop is going to tell us a lot," Arvidson said. It has "high discovery potential," he explained. Scientists plan on spending time looking at the outcrop of exposed rocks, then command Opportunity to climb up and out of the small crater, he said.

Ron Li, MER Science Team Member from Ohio State University, said a 3D map has been created -- the first map from inside a crater thanks to Opportunity-gleaned data.

Crater slope information can help steer the robot out and about onto the flatlands of Meridiani Planum. There are several candidate pathways for the robot to exit the crater, Li said.

Opportunity has a "very benign egress path," said Daniel Limonadi, JPL Rover Systems Engineer. "We're ahead of schedule."

Several key steps remain in setting the rover free from its landing platform, Limonadi said. If all goes well, the robot will wheel onto Mars at the end of its 7^th day at Meridiani Planum, he added.

Once the robot steers itself off the stationary lander platform, it will park nearby and begin a series of soil experiments.

Although in close proximity to Opportunity, the rock outcrop is to be investigated several days from now.

"It is too early to tell what type of material makes up the outcrop. I have my guesses, but will await more data," said Jim Rice, a MER science team member from Arizona State University in Tempe.

"I think this site, namely the outcrop is a treasure trovea very real geological history vault just awaiting our further examination," Rice told SPACE.com .

Rice said that finding martian bedrock is a "golden opportunity" and one that the scientific team will be able to aggressively seize upon thanks to the rover's mobility and science payloadto "poke and prod" this magnificent chunk of martian antiquity, he said.

"Who knows what kind of history is locked away in its layers," Rice concluded.