Lab-built components bound for outerspace
Chances are pretty good that Jerry Hand and Jim Safly will never travel to outer space. Fishing trips to Canada or winter
excursions to Florida are more likely destinations for the two Ames Laboratory machinists who grew up as neighbors on
Yet the two are involved in a project that could eventually see some of their handiwork
make the trip into space aboard the Shuttle, the International Space Station, or future
space flights to Mars. Hand and Safly have been busy the last month fabricating
components for equipment designed to test and monitor the quality of spacecraft drinking
The problem NASA faces in extended space flights is being able to carry sufficient
amounts of water to support space crews. As a result, every drop of water is precious
and most, if not all of it, needs to be recycled, through filtering and treatment with iodine
and silver, into potable water.
Because of its expertise in electrochemical sensing and microelectronics, Iowa State
University's Microanalytical Instrumentation Center received a three-year NASA grant to
help solve the problem. Marc Porter, MIC director and ISU chemistry professor, and his
research team came up with a method for testing samples using a small, portable
But what works here on Earth won't necessarily "fly" in the zero-gravity environment of
space. The team needed a way to ensure the water test samples are contained and that the chromatograph be held firmly in
place. With help from CIRAS engineer John Roberts, designs for a two-piece plastic coupling and a mounting bracket were
developed. That's where Hand and Safly enter the picture. Hand went to work on the coupling, while Safly started on the
Starting with a solid blank of Delrin, a tough, high-density plastic, Hand had to mill the intricate shape of the coupling,
including grooved seats for rubber O-rings only a few thousandths of an inch in size. Unable to make such precise cuts with
conventional milling tools, he turned to a relatively new piece of equipment in the Metals Development Machine Shop, the
Robofil 290 Wire Electrical Discharge Machine - EDM for short (see the related story directional).
"I had to make a separate cutting tool for each of the profiles," Hand says, showing how the
cutting edge of the tool perfectly matched the lathe-turned profile of the coupling. "The EDM
gives us capabilities we've never had."
Outfitted with the rubber seals and a thin membrane, the coupler fits into a port in the
chromatograph. The water sample, collected in a syringe, is injected into the system, and a
reading is taken to determine the amount of iodine present. After the initial coupling design
proved to be too difficult to separate, Hand modified the pieces to come apart with a squeeze
and a slight twist.
Meanwhile, in the Sheet Metal Fabrication Shop, Safly started turning a flat piece of 16-gauge
stainless steel into the U-shaped mounting bracket for the chromatograph. Once it was cut out,
the bracket required precision drilling for the mounting screws. Then Safly had to carefully
bend the metal to its final form using the shop's large sheet metal brakes.
"Normally, we don't receive plans with this amount of detail," Safly said of the computer-generated drawings spread out on
his workbench. "And most of the time we don't get to see how the pieces we fabricate actually work. We simply move on to
the next project."
The components got a preliminary test this month when Porter and visiting scientist Matteo Arena traveled to Houston and
made test flights on NASA's KC-135 turbo jet. Nicknamed the "vomit comet," the plane makes a series of parabolic climbs
and dives, providing a brief zero-gravity environment during the steep dive.
"It was an intense sensation for us, but the experiment went very well," Arena said, adding that the components made by
Hand and Safly worked perfectly.
Not bad for a couple of local farm boys.
by Kerry Gibson