These are just the problems of getting to Mars and back with the healthy body you started with. What about once you're there? The lander's down, the dust has settled and you are required to open the hatch and step outside. This is the moment you've come for. What in the worlds do you wear?

"I'd like to put on my sweater and a skirt if I've got work to do on Mars," Newman says. "The moon suit was over 100 pounds, and bunny hopping was fine for what they did. But we have to stop thinking big, white and clunky." She has started designing her own suit, which will look nothing like anything we've seen before.

Newman's tinker toy for this project is a robot she has on loan from NASA. It's a 6-foot-2-inch black-and-silver humanoid that Newman calls "Tallchief" because she considers it as elegant as Maria Tallchief, the Native American prima ballerina who founded the New York City Ballet with her husband George Ballanchine. Tallchief (the robot) is wired to a computer and a sensor suit. The way to move Tallchief is to get in the sensor suit and move yourself around. Whatever you do, Tallchief does.

The robot is a human engineer's dream because you can poke and prod it invasively. To design a suit for running around the surface of Mars -- Newman insists: no bunny hopping -- she needs to know, for instance, how much torque a human applies at the knee when he pulls his back leg forward while walking in Martian gravity (Martian gravity is three-eighths of Earth's gravity: If you weigh 150 pounds here, you will feel like 56 pounds there). As Tallchief walks on the treadmill next to the graduate student who controls it, Newman can jab a torque measuring device into the robot's knee joint. You can't jab a graduate student.

For Newman, the ultimate Martian space suit should be a "smart second skin": light and thin like a wetsuit, smart like a computer and wired like the human nervous system so that it knows everything about the precious body inside it. Of course, it must also resist Mars' frigid temperatures, provide oxygen so astronauts can breathe and apply terrestrial atmospheric pressure so their blood doesn't, literally, boil.

Newman also wants her smart-skin space suit to help astronauts move, giving them superhuman flexibility as they wander around the hills and valleys of Mars. And she envisions the opposite: The suit could be programmed to resist astronaut movements in zero gravity settings, so that wearing the suit is an exercise in itself -- a proper countermeasure to bone and muscle loss. With nanotechnology's advances making smart devices small, Newman's ideas may well be buildable by the time NASA is ready to slate a manned mission to Mars. Though the recent losses of remote-controlled craft around Mars have paused all planning for the time being, Newman points out that planetary alignments give prime launch windows in 2011, 2014 and 2018.

Engineers are one of the pools NASA fishes for astronauts. Given her age, her smarts and her life-long athleticism, it's not hard to imagine Dava Newman leaping at the chance to man the mission to Mars. Asked about it, she talks of "service to my country so it doesn't matter how I'm involved" and "I would only go if it were the best thing for the mission," and ends with, "If I could go with my sweetheart, sure." Sweetheart Guillermo Trotti echoes her; it would be much better to go together. Years of isolation are tough on the strongest of souls. But Trotti doesn't practice circumlocution: The truth is either of them would go in a second.

Newman is not funded by the military, though there is plenty of money available from the Pentagon for her type of research. But she has become quieter over the years on this point of policy as she has risen to the tenuous rank of associate professor at MIT, an institution that, for all its greatness, has a knack for politicizing its tenure track and a reputation for not promoting women (the record is improving). The purest of scientists, which MITers certainly consider themselves, are always supposed to say that policy is not their business: Who cares where the money comes from? Just do the work. So it is unclear whether Newman's new silence on the military is an actual fading of feeling -- or realpolitik in a department that would consider a commitment to the peaceful exploration of space too political for a pure scientist.

Or perhaps it is enough that her efforts will allow more humans to spend more time in space. After all, the more bodies living aloft in cooperative enterprises like the International Space Station, the more out-of-place the new Star Wars initiative will seem (President Clinton signed off on Star Wars last year, despite the plan's international status as technologia non grata).

Newman also works hard to bring young people into her field. Her Web page on the National Academy of Engineering site is a solicitation to young women to become engineers. She is famous as a teacher at MIT for the final project she runs in her course "Introduction to Aerospace Engineering and Design." As they learn about pitch, trim, stability, thrust and yaw, the undergraduates must design and build motorized remote-control blimps. On a sunny day at the end of the semester, they race the blimps against each other along an aerial obstacle course around the MIT field house. According to Dr. Lawrence Young, a senior professor in her department, Newman's you-can-do-it-too approach brings out the challenge, the art and the fun of engineering that is too often lost in textbook teaching.

She is where she wants to be, says Newman -- teaching people to fly and engineering the systems needed to get our fidgety species to Mars, while drawing on her earliest inspiration: "The awe and mystery and expectation that have been with me since I was 5," when Armstrong and Aldrin, wearing their big, white and clunky suits, bounced around the moon on her television set.

Recent Stories