On January 3, much of the world focused on the mission control room at the Jet Propulsion Laboratory (JPL) in Pasadena, California on news that JPL's robot rover Spirit had landed safely in Mars's Gustav Crater. (Three weeks later its sister rover, Opportunity, successfully landed on the other side of the planet.) At the heart of the excitement-but at the fringes of the news coverage-was Lebanese-born JPL Director Dr. Charles Elachi, under whose supervision scientists were controlling the $400-million dune buggy.

Just a day earlier, another JPL probe, the spacecraft Stardust, had sped through the comet Wild 2, some 1.1 billion kilometers (708 million mi) from Earth, and it had sent back photos that are "the best ever taken of a comet," says Elachi. Stardust also captured cometary material to return to Earth.

"But Spirit," he says, "captured imaginations."

Powered by solar energy, Spirit will wander some 10 to 15 kilometers (6-9 mi) during the next three months or more as it analyzes soils and drills into rocks in its search for water-bearing minerals or minerals deposited by precipitation, evaporation or hydrothermal activity.

"We had as many as 1000 scientists and engineers working at the peak of the Mars rover project, many of them young people in the early years of their careers, many of them women," comments Elachi, who was selected over 73 other candidates to head JPL in 2001.

"I don't participate in every detail of the dozens of space projects we are conducting, but in the case of the Mars rovers, I had to concur with the key decisions on configuration, such as when to release the parachutes that softened the landings," Elachi says. "When undertaking an exploration, you must be prepared for and aware of failure, yet work very hard for success. If you're well-prepared, your chances of success are much better.

"The exhilaration is indescribable," he continues. "Exploration is about opening new doors and stepping into the unknown. Throughout the ages, explorers have pushed the limits. I think I have a taste of what Columbus, Magellan, Cook or Lewis and Clark must have felt."

The chances of success for the Mars rovers weren't that promising. The planet's harsh environment has made it a Boot Hill for earlier probes, including seven Russian attempts, three American ones and a British lander that failed in January.

"I find it amazing that we've developed the capability to send a craft 500 million kilometers [310 million mi] into space and seven months later land it within 80 meters [265'] of its target," he notes. "Spirit was moving at 20,000 kilometers per hour [12,000 mph] as it approached Mars and then had six minutes to decelerate to zero velocity. If our calculations had been just seconds off, it would have crashed."

A larger JPL-built lander, the Mars Science Laboratory (MSL), is scheduled for a rendezvous with Mars in 2009. It will use a miniature nuclear-power system for more detailed explorations.

Does Elachi think any part of our solar system beyond Earth has sustained life?

"Possibly some microbes or cells existed at one time on Mars," he responds. "We think that organic material may also be detected in comets, on the Saturnian moon Titan or on Jupiter's moon Europa, which has a surface that looks like floating ice."

The world will know much more about Titan after JPL's Cassini spacecraft enters orbit around the ringed planet on July 1 and releases its piggyback probe to penetrate Titan's thick atmosphere later in the year.

Elachi first gazed at the stars from his boyhood home in Rayak, Lebanon. He came to the United States as a graduate student and enrolled at the California Institute of Technology in Pasadena, where he completed his doctorate in 1971. His first work at JPL was with the Venus Radar Project, for which he led development of spaceborne imaging radar. Today, Elachi is the world's foremost expert in radar imagery of planetary surfaces-in addition to his specializations in the interpretation of active microwave remote sensing, wave propagation and scattering, electromagnetic theory, lasers and integrated optics. It was his task force that created the "corrective lens" for the Hubble Space Telescope in 1993.

His skills have been useful on Earth, too, scanning California's San Andreas fault, searching out traces of ancient roads near the "lost city" of 'Ubar in Oman and mapping subsurface valleys in Egypt and Sudan -as well as the Great Wall of China. Elachi stresses that radar mapping doesn't magically outline archeological ruins. Rather, it shows traces of old riverbeds, the compacted soil of long-forgotten roads and overall patterns that offer clues about what an environment was like thousands of years before.

As a professor of electrical engineering and planetary science at the California Institute of Technology before coming to JPL, Elachi wrote three textbooks and more than 230 scholarly papers and lectured extensively. Wherever he speaks, he says, he always remembers that he is following in the footsteps of medieval Arab scientists-many of them astronomers, navigators and engineers-who laid the foundations for today's understanding of the world.

As a boy, Elachi says, he was especially proud of the stars that carry Arabic names, given them by those who first charted the skies. Just in the constellation Pegasus, there are Enif, Aldebaran, El Nath, Markab and Algenib. Elsewhere in the sky, much closer and smaller, floats asteroid 4116 Elachi, named for him in 1989 in recognition of his contributions to planetary exploration.

Does he think the successes of the Mars rovers will indeed pave the way for a manned mission to Mars?

"Manned exploration is our long-term goal," Elachi says. "There's no doubt in my mind that we will have stations on the Moon and on Mars within this century. Just think what we've accomplished in the last hundred years since the Wright brothers first lifted their little contraption into the air in 1903."

Beyond that, he says, it is the future searches of neighboring solar systems for habitable planets that excite him most. "These missions may well find the answer to one of the most fundamental questions we humans ask: 'Are we indeed alone in this universe, or has life flourished elsewhere?' Perhaps Aldebaran is sending out its own explorers

Pat McDonnell Twair ([email protected]) worked for six years as a journalist in Syria. Based now in Los Angeles, she is a free-lance writer who specializes in Arab-American topics. She has written an account of her life in the Middle East, Two Thousand and One Syrian Nights.