During my time working as a contractor for NASA, I was presented with several opportunities to wear an Extravehicular Mobility Unit (EMU), the suit that spacewalking astronauts have used since the beginning of the space shuttle program. While the majority of my experience as a suit-wearing "test subject" was exciting and enjoyable, it wasn't all fun and games. The EMU has a way of showcasing the humility of its occupants and I was no exception.
When people ask me about my experience in the EMU, I usually tell them, "The only thing better than getting into an EMU is getting back out." It may sound cavalier, but it's the most efficient wording that reflects the love-hate relationship that I slowly developed with the suit. I never turned down a chance to wear the EMU in any capacity. I was often sleepless with excitement the night before. At the same time, I was never sad for those events to come to an end. All I wanted was to slither my body out of its puffy man-made cocoon and pop a few ibuprofen to ward off the aches and pains that often followed.
The fun parts of being in the suit are pretty obvious. Who wouldn't jump at the chance to play junior astronaut? Those good parts always outweighed the bad. It took a while for many of the downsides to emerge, but some unexpected challenges just couldn't wait. This story reflects the beginning of my gradual awakening to the indignities, discomforts, and dangers that are inextricably linked to the fun and exhilaration of wearing an EMU.
If the Suit Fits…
Rather than being a custom-tailored suit for each astronaut and test subject, the EMU is a modular system consisting of several components (legs, arms, etc.)…each available in a few different sizes. It is your specific combination of parts that makes the suit fitted to you. Nailing down the sizing for someone is a process that requires a minimum of three separate events. Some astronauts come back again and again during their career to address trouble spots or accommodate changes in their body.
During the first sizing step, I had to stand partially naked while technicians compiled a long list of my body measurements. This data allowed engineers to take a preliminary stab at what components would fit me.
A week or two after getting measured, I was allowed to try on a few different sets of gloves that had been picked out for me. Of all the different EMU components, the gloves have the largest variety of sizes to choose from. For these types of events, the gloves are attached to arm components within a vacuum box. The pressure difference afforded by the box provides the same feel as gloves attached to a pressurized suit, but with a much smaller overhead.
Another week or so after choosing my favorite gloves, it was time to go all the way and put on the full EMU. I don't recall having any apprehension about this…just excitement. I had watched people get into and out of EMUs every day as part of my normal job duties. It was always a non-event for them, so why should I be any different?