The last 3-1/2 years have been the most grueling of Julie Townsend's life. She's forgone nights out with friends, time with her family, sports, travel, even recreational reading; she's let calls from siblings go unanswered, and gone weeks between trips to the gym. All that, for a dream that dates back to childhood: space exploration and the national goal of landing a rover on Mars.
Now, after NASA's Spirit rover navigated the thin Martian atmosphere Jan. 3, bounced to a stop on the racetrack-flat Gusev Crater, and transmitted pictures to earth, Ms. Townsend is realizing that the next few months may be harder still.
"This is what I've been working for my whole life," she says, having spent most of it, since June 2000, designing software to detect and circumvent problems with a space module or exploration craft - complications caused by heat, moisture, wind, or dust. "When the rover landed safely, my parents called the control room and screamed into the phone, 'Honey, we're so excited' - and I said, 'Mom, look what we did: We're on the surface of Mars!"
Along with the 600 or so scientists and technicians here at Jet Propulsion Labs in Pasadena, Calif. - and up to 400 others at aerospace companies and in academia nationwide - Townsend is part of an elite cadre immersed in one episode of the ultimate science project: expanding the art and science of the possible.
It's an immersion so deep, a devotion so headstrong, that it's changed their sense of time itself. Townsend doesn't come to work in tune with the rhythms of the normal American workday: Her watch, and her schedule, is set to time on Mars, where the sun rises later and sets on a dry and desolate world. At one point, working a shift from midnight to 8 a.m., she saw no one for an entire week.
"These people are here working around the clock with intensity and focus because they have a sense of wonder and awe about what is out there" says Charles Elachi, director of Jet Propulsion Labs, which has several space missions running simultaneously with the current Mars mission. Dr. Elachi himself was imbued with a sense of awe while growing up in Lebanon, and still recalls the summers he slept on his patio, gazing up at stars.
"I just always wondered if there are others like us sitting up there. So I got excited about science and space exploration and astronomy, and I guess it never left me. It's the same motivation that unites all of us here."
Elachi, Townsend and others describe the latest mission to Mars as a combination of real-life problem solving; Flash Gordon fantasy; personal and collective quests; and the simple, practical application of new technology.
They also see it as the educational frontier for coming generations. "If anything excites me more than having accomplished this landing successfully, it's going out to schools to excite the next generation about the exploration of space," says Townsend. "This is all about discovery of the unknown, pushing the limits of what you think you can do, seeing places that no one else has ever seen."
Now with one rover successfully landed, and another due to descend elsewhere on the rockscape Jan. 25, Townsend and other scientists say they are caught between elation, exhaustion, and cautious optimism. One key phase is over; but another has just begun.
Teams of scientists and engineers are still analyzing data from the entry, including temperature, wind, and moisture information, with hopes of being still more accurate and safe on the second touchdown. Surprising many engineers, the 384-pound rover landed upright and began communicating with earth immediately. Airbags deflated, solar panels deployed, and camera and antennae began transmitting data and pictures to earth.
After so much preparation for so long by so many, the moment of entry was an almost unbearable moment of truth, an emotional verdict on years of work.
"It was the highest stress you can imagine," says Jason Willis, flight director for entry, descent, and landing. "Everything came down to a single moment. When we finally knew we had done it, we were overjoyed with relief."
Mr. Willis describes the last three years as battling the clock on technical issue after technical issue - from redesigning airbag systems to reprogramming the module to avoid solar flares that could destroy or misguide the spacecraft.
"We suddenly had to cram all our navigational activities into two-week time periods when the flares were on the other side of the sun," says Willis. "Every time something would come up we would resolve it and think we were fine. Then, three or four days later, we'd get hit with the next big issue."
Another big issue surfaced just five hours before landing, when officials had to make decisions on circuitry that might have been damaged in overly robust tests before the launch. Scientists feared that some of the switches guiding the landing pyrotechnics might fail if activated by the on-board computer rather than by mission control.
"It has been very, very challenging all along," says Elachi, who is overseeing the entire mission. "We would sit around and listen to all the points of view, and all the recommendations, and then someone had to make a decision. And it was usually me, because the buck stops here."
Now, the next big issue is what cameras on the land rover will see and what directives they will suggest for operators on earth. Learning from the Pathfinder mission, engineers have designed a rover that can go farther, faster, have a greater capability for photos, and does not need to stay in line of sight with the landing module.
"We are carrying more instruments, better cameras, and can go further from the lander," says Joy Crisp, lead scientist for the mission. "What will be exciting now is watching how scientists make their decisions on where to go next, based on what they see from the pictures."
For nearly everyone here, the moment has been a lifetime coming. At age 4, Townsend sat transfixed before a TV image of the first US shuttle mission. At 13, she took a college-level course on aerospace engineering and robot mechanics, and launched a dozen eggs in a makeshift rocket just to see if they would break. Three years ago, she left her PhD program at Stanford University to join the JPL-sponsored mission.
Dr. Crisp also played a major role in the 1997 Pathfinder Mission to Mars.
"This has been the most daunting project of my career, the most difficult thing imaginable," she says, describing three-plus years of 75-hour weeks. With memories of major problems from the ill-fated Pathfinder mission - including dust on rocks that contaminated equipment and technical problems that straitjacketed the rover's mobility - the current project planners had to design far more sophisticated equipment in far less time.
One thing that fuels the scientists' motivation is the public response to the Mars mission.
Traffic on websites operated by NASA climbed Sunday, as computer users around the world checked the Spirit rover's first images of Mars. NASA recorded 109 million hits on its home page and related websites during the 24-hour period coinciding with the Saturday landing on Mars.
Nearly 17 hours after the successful touchdown, that figure had more than doubled, says Brian Dunbar, NASA's Internet services manager.
"As we put out more pictures, we'll continue to see that," Dunbar says of the steady rise in traffic. To support the onslaught, NASA is relying on 1,300 servers around the world to host websites with details of the Spirit mission.
So far, scientists are encouraged by the clarity of images coming back and by the flat terrain. While some observers feel the red planet is just a big hunk of spinning rock, scientists say it is perhaps more like Earth than any other planet. And they say the rover's placement in stark terrain will be a boon in studying Mars's age, and the possibility of life on that planet in the past. "Landing in an area like this is a bonanza for a geologist because the geology is exposed," says Elachi.
"The most interesting thing about Mars is that it looks like it had liquid water," adds Crisp. "Life may have gotten started there, and we can figure that out by looking at the rocks."