|Machinists to the Stars
|JPL Machinist works on Mars '03 rover.
It's the middle of the night at JPL, and the usual dozens of deer are on
their nightly foraging rounds across the campus. Mars is up. So is the
Moon. And so are nine machinists in the lab's high-precision fabrication
shop, working the second shift that ends between midnight and 3 a.m.
They are part of the round-the-clock team turning out odd-shaped pieces
of metal that will become robots destined for Mars.
Night shift supervisor Gary Keel holds in his hand an improbable mix of
geometric shapes that somehow meld smoothly together. Finely machined
out a solid, 25-pound brick of titanium, the part looks like a mechanical
dog's leg as dreamed up by a computer. In a way, it is.
Only this is a leg for a rover of a different kind - it's a wheel strut for
one of the two twin Mars Exploration Rovers now being built for launch in
2003. This part is one of thousands that will comprise the rovers.
The part displays a mathematical complexity made possible only
through the speedy calculations of computer-aided design. Rendering it
into a real part from a drawing falls to Keel and his colleagues in the
|Artist's concept of 2003 Mars Exploration Rover
About eighty percent of the rover parts are of a more routine sort that
will be made by machinists outside of JPL. Some parts, like the launch
vehicle adapter that connects the spacecraft to the rocket, are huge - the
size of a round banquet table. Others are smaller than the diameter of a
pencil. Large or small, the most exotic pieces stay at JPL with staff
machinists, now available 24 hours a day, seven days a week through
the crunch time of the rovers' assembly and test phase.
"We Get the 'Oh No!' Parts"
"We get the 'Oh No!' parts" says Keel. "The 'Nobody
Else Wants to Touch This' parts." Engineers often want to keep the
most complicated and challenging machining in-house, he says. That way,
they can check the progress with the machinists who are bringing the
new parts into being, and have an opportunity to make adjustments
if needed. The relationship is known as "concurrent machining
Mike Mangano, the Mars Exploration Rover mission's mechanical
systems project element manager, explains the value of being able to
communicate with the machinists on site: "You can do the design,
you can put it on paper, but until you start to actually make it, you
don't know what kinds of problems you're going to run into."
Machinists to the Stars
Machinists to the Stars