* Ray Arvidson is busy at NASA's Jet Propulsion Laboratory as No. 2 scientist on the rover exploration project.

The airwaves were abuzz Thursday with news that President George W. Bush would propose manned missions to Mars. But Ray Arvidson had more urgent business with the Red Planet.

"There have been rumors going on for weeks and weeks and weeks," he said, shrugging. Arvidson , a Washington University planetary scientist, is the No. 2 scientist on the most audacious journey yet to Mars -- the Mars Exploration Rover mission.

"Didn't his father propose something like that?"

Minutes later, in a wide, low room at NASA's Jet Propulsion Laboratory, Arvidson was taking stock of about 20 of his science troops huddled around clumps of tables and monitors. Outside it was pitch black, about 9 p.m., but the Science Assessment Area was on Mars time -- nearly high noon.

The scientists' work would help lay out vital mission plans as the Spirit robotic rover came down from its lander onto the floor of Gusev crater, a step expected this week. The craft landed on Mars on Jan. 3.

Arvidson 's tasks for the evening included keeping the scientists creative and focused. Engineers and researchers alike were eager to get the rover moving. Hopefully Spirit would find evidence that water once existed in the area, what seemed to be a dried Martian lake.

"They're trying to figure out how many rock types there are, and whether or not that's a crater," he said, pointing to a group debating a giant photograph of the orange landscape. That would be crucial to plotting the rover's course. A group of geologists was scrutinizing photos to pinpoint Spirit's position.

The anticipated White House announcement of even bigger missions to Mars in the decade ahead didn't distract the researchers.

"This is more exciting," Arvidson said.

"We're on Mars now," said Texas A&M researcher Mark Lemmon, turning back to his analysis of Martian dust in the atmosphere - work crucial to Spirit's solar panels.

Then the loudspeaker cracked - the rover was about to stand up.

Arvidson hurried to the Mission Support Area, a large, triangular room filled with desks, computers and giant wall displays. There, engineers checked one system on the robot after another. Was the science team ready for stand-up?

Arvidson said yes. Minutes later, engineers transmitted commands to the rover - more than a hundred million miles away - to stand.

About 40 minutes later a cheer came from the back of the room. Spirit had unfolded its front two legs and risen into position. The mission was a giant step closer to getting what the engineers call "six wheels on dirt." Soon after, Arvidson appeared, and a friend asked him if he was enjoying himself.

"Kind of a career highlight," he said, to grins. Engineers appreciate understatement.

When the rover hits paydirt, Arvidson , 55, will be among the most visible scientists describing the adventure to the cameras. As deputy to Cornell astronomer Steve Squyres, he'll coordinate daily meetings between researchers and engineers to decide which tests to run when, what risks are worth taking and where Spirit should roll.

Insiders on the mission say the pair's complementary styles have served the team well in the more than five years of work leading up to touchdown in Gusev. Arvidson wears a beard that suits his unassuming manner and moves smoothly and silently as he makes his daily rounds. Squyres, a decade his junior, is a wiry bundle of energy who comes to work in leather boots and ripped jeans. When Spirit reported its new posture Thursday, Squyres burst into the room wild-eyed, hugging engineers and bouncing his head as "Get Up, Stand Up" by Bob Marley played on the loudspeaker. Arvidson missed the news, busy talking to scientists and arranging a surprise birthday party for Squyres.

Once the rovers begin exploring, the pressure of the daily cost will mount on the duo and their scientists.

"If we goof up we lose about $4 million," said Arvidson .

Colleagues say they are confident with Arvidson sharing the helm of the science team.

"He typically goes, 'Look, folks, here's the simple solution,' and everyone looks up. And he's right," said Roger Phillips, a Washington University planetary scientist in the department of earth and planetary sciences, of which Arvidson is the chair.

Doing the hard work

Most landing attempts on Mars have failed. The most recent apparent failure came just a few weeks ago: The British Beagle 2 probe, which was supposed to land on the planet Christmas Day, has yet to be heard from.

NASA's Viking I and II, projects in on which Arvidson assisted in 1976, were clunky landers that stayed put. Sojourner, in 1997, was a pipsqueak of a rover. Spirit and Opportunity, a second rover that is due to join Spirit on Jan. 24, are decked-out robotic geologists the size of golf carts.

Before the Viking I landed, scientists didn't know whether the robot cameras would detect lichen, alien bushes or even animals, as Carl Sagan publicly wondered. Viking's robot arms conducted chemical experiments, but scientists failed, as consensus has it, to find the very specific kind of biological life they were looking for.

"We realized that Viking was the wrong approach," Arvidson said. Researchers recognized later that any potential life in the soil probably would have been destroyed by radiation.

Now scientists have changed their goal, looking for evidence of water as a first step towards detecting previous life on Mars. (Project scientists say they just wouldn't know how to identify life that wasn't based on water.)

Arvidson began his journey towards the top of the Mars world in 1969, as a senior at Temple University in Philadelphia. At the time he was set to study marine biology, but a poster offering graduate work with Tim Much at Brown on planned Mars missions caught his eye. He took off to join Much, a highly regarded space scientist, on July 20, 1969, the day that Apollo 11 landed on the moon.

Under Much, Arvidson found himself at the forefront of the nascent planetary movement. His focus was evaluating images, a specialty honed during stints with the Air Force ROTC. In 1973, he helped analyze the first images of the whole surface of Mars sent by the Mariner 9 craft.

"People tended to look at individual pictures, and Ray, together with Tim, set up a system," said James Head, a planetary geologist at Brown University who knew Arvidson as a graduate student. The method used a device called a digitizing board to plot craters on the planet.

Then came his work on planning and managing the imaging work on Viking. "Carl Sagan would be on 'The Tonight Show,' Tim Much was hobnobbing with the New Yorker, and Ray was doing the hard work," said friend Benton Clark, a planetary scientist with Lockheed Martin who serves on the current mission's science team.

Since then, Arvidson has been a fixture in NASA's efforts to explore the solar system, helping plan and run the 1989 Magellan mission to Venus as well as the Mars Observer and Mars Global Surveyor orbiters, both currently scanning the planet. Wearing other hats for NASA, he's tested rovers and archived reams of planetary data.

Arvidson has built his career conducting what space-heads call remote sensing - taking scientific measurements from afar. "If you ask him what a rock is, he'd say, 'Back up a few miles,'" said his wife, Eloise Arvidson , an administrative assistant at the Logan College of Chiropractic in St. Louis. Spirit and Opportunity give Arvidson the chance to return, in a way, to his roots in on-the-ground geology, although it will be robots' hands getting dirty, not his.

Those roots took hold in high school in southern New Jersey, where his future father-in-law, Bill Kettleson, introduced him to the geology of the area.

"We used to go out on field trips to look at fossils, snake teeth," recalled his wife. "That sort of got [Ray]." Arvidson came to Washington University as an assistant in 1974 and stayed. Their son Lars, 25, works for the university, while Timothy, 30, serves in the Navy.

Arvidson doesn't just study other planets. Using the same method that NASA used to map Venus, Arvidson and his students analyzed the Missouri river flood plain after floods in 1993 and 1995. As department chairman he has strengthened the faculty in earth science. And he's a popular teacher at the school, running a program called Pathfinder for talented students to study geology and environmental science.

"The first day of class he says, 'Just call me Ray,'" said Matt Klasen, a sophomore who went with the Pathfinder program over the winter break to Hawaii. When Spirit landed on Mars, Arvidson was on a flight towards Los Angeles from Hawaii, unwilling to cut short his time with the students.

=== Link to more information about the exploration of Mars online at STLtoday.com/links.

(1) Photo by NASA VIA GETTY IMAGES - This Martian landscape, with part of the Spirit rover showing at the bottom, was among the stunning images beamed back to Earth last week by the robot explorer's cameras.
Note: photo (1) ran in the THREE STAR Edition only with the following caption:
NASA VIA GETTY IMAGES - This look at the martian landscape surrounding the Mars rover Spirit is the first 3-D stereo image to be released from the rover's navigation camera.
(2) Photo by THE ASSOCIATED PRESS - At a news conference Wednesday at NASA's Jet Propulsion Laboratory in Pasadena, Calif., Ray Arvidson (center) sits with other members of the mission team as a plaque dedicated to the memory of the astronauts of the space shuttle Columbia is displayed.
(3) Photo by JENNIFER GRIFFES/WASHINGTON UNIVERSITY - Professor Ray Arvidson (left), works with students from Washington University in Hawaii in August.
Note: photo (3) ran in the THREE STAR Edition, page A7.
(4) Color PHOTO headshot - (Ray) Arvidson
Mission is "a career highlight"

Correction: Correction published Tuesday, January 13, 2004 - The late Brown University professor Tim Mutch's name was misspelled in this story Sunday. E-mail the Online Editor
© 2002 St. Louis Post-Dispatch

Correction: Correction published Tuesday, January 13, 2004 - The late Brown University professor Tim Mutch's name was misspelled in this story Sunday.

 
Full text of archived story

* NASA's Spirit spacecraft is set to touch down Saturday on Mars and look for signs of life -- if it survives the landing. That's a big if, as the European Space Agency's recent experience shows.

As anxiety builds at NASA's Jet Propulsion Laboratory late Saturday night, antennas around the world will be listening for the tones.

The survival of the rover spacecraft Spirit through the Red Planet's atmosphere will be confirmed by a series of electronic pulses as it careens toward the frigid surface at 12,000 mph.

Seen as colored bars on a screen at the control center, for several minutes the tones are all that will tell engineers at the mission control center in Pasadena, Calif., whether the fragile craft has survived the 300 million-mile journey -- or not.

"There are so many things that have to happen in that time frame," said Bradley Jolliff, a rock expert who is one of a handful of Washington University scientists playing key roles on the mission.

"That's five, six, seven minutes of heart-wrenching excitement."

That could stretch to 24 hours of heart-wrenching excitement, if Spirit needs that long -- as it might -- to re-establish contact.

A fruitful Mars Exploration Rover mission could yield new clues about the wet past of Earth's closest neighbor, and possible signs of ancient life.

Additionally, speculation is high in Washington that a successful mission could spur President George W. Bush to announce a new space initiative, including a manned mission either to the moon or to Mars. That announcement could come during the State of the Union address this month.

Spirit is the first of two rovers scheduled to land on Mars this month.

A British-led robotic mission to Mars had been scheduled to land Dec. 25, but attempts to establish contact with that craft, called Beagle 2, have been futile.

Ray Arvidson , a planetary scientist and head of the NASA mission's science team, said the British failure has not increased the pressure on his team, which he said had "checked, double-checked, triple-checked" every facet of the equipment.

But Beagle's fate has once again demonstrated the difficulty of space flight, manned or robotic.

"We have our own jitters," said Arvidson , who has planned and helped run NASA probe missions since serving as an assistant in 1976 on NASA's Viking 1 mission. "Landing on any planet - going through its atmosphere - is a risky venture."

University researchers who will serve on the mission's science team include Jolliff, geochemist Larry Haskin, spectroscopy expert Alian Wang, and planetary scientist Edward Guinness. Frank Celos, a graduate student, and Bethany Ehlmann, who recently completed her undergraduate work, also have working roles.

Thirty-one missions to Mars have been tried since 1960, and most have failed.

Yet the fruit of the successful ones surpassed expectations. NASA's Viking I and II, which included orbiters as well as landers, sent more than 50,000 photos of the planet from 1976 to 1987.

In 1997, Mars Pathfinder landed successfully on what is believed to be the site of an ancient flood. In its three-month exploration of the area, which lasted far longer than expected, the rover's cameras and probes suggested a once-vibrant world of water, warmer temperatures, clouds and wind.

Launched in June, Spirit will face the most critical moments of its journey during a six-minute entry into the Mars atmosphere beginning at 10:35 p.m. Central time.

As in previous missions, the rover will deploy a heat shield, a parachute, retro rockets and a protective cocoon of airbags. NASA expects the 400-pound rover to bounce as high as 50 feet upon impact, and to roll for more than half a mile before coming to rest.

Then the lander will unfold and, over the course of a week, be prepared to hit the Martian dirt. On its way to Mars, the six-wheeled rover is folded flat.

Spirit touches down Saturday in Gusev crater, a 90-mile wide hole found just south of the Martian equator, 155 miles from Apollinaris Patera volcano. There, scientists hope to find, for the first time, sediments deposited over the 4 billion-year history of the planet.

Spirit's twin, called Opportunity , is scheduled to land on the opposite side of the planet on Jan. 24. The rovers can travel up to 44 yards on a Martian day, called a sol, which is equivalent to 24 hours, 39 minutes and 35 seconds on Earth.

If functioning properly, the pair will communicate directly to Earth as well as send signals to two orbiting spacecraft, Mars Surveyor and Odyssey, which will relay the messages back to NASA scientists.

Color Photo - A LOOK AT THE EXPLORATION ROVER
Artists depict how the rover will land on Mars and how it works. A4

E-mail the Online Editor
© 2002 St. Louis Post-Dispatch