JPL Machinist works on Mars '03 rover.

Because of the very strict constraints on size and weight, the spacecraft, landers and rovers are compactly layered inside of one another like Russian dolls, says Mangano. "We call it configurationally challenged," he says. The geometric complexity of some of the parts reflects the creative design that packs a lot of engineering and science capability into a relatively small spacecraft system.

The rover and lander systems require some three dozen gears and motors. Some of these help open and unfold the landers to release the rovers, some deploy scientific and communications instruments, and some are part of the rover's mobility and steering system. Building those and other parts for the project is driven by "a pretty ambitious schedule," says Mangano. Hence, Keel and other JPL machinists are burning the midnight oil.

"We interact a lot with the engineers," says Keel. Working against the project's tight deadlines, "If we have a question, they're going to get out of bed and come in and help us."

Spacecraft-Building, Hands-on

Keel, who grew up in Southern California's Simi Valley with a passion for science fiction and dreams of a baseball career, instead set out on a path that would lead to Mars when he took vocational machine shop classes at Royal High School. His shop teacher recommended him for an apprenticeship at a local shop making general industrial parts for autos, computers and safes. He later worked at Rocketdyne on parts for the Space Shuttle launch system. Ten years ago, he joined JPL.

"Mars Pathfinder was my first project where I worked from the start to finish," said Keel. Then he worked on parts for the Cassini spacecraft now enroute to Saturn. "Those were the first missions I felt part of."

For a machinist, Keel says, "this is the best place in the world to work. It's not the same thing day in, day out. There are challenging opportunities and a chance to advance your career. And this is the only place I know of where you work on a part for something and see it on the front page of the Los Angeles Times making history a few years later."