Today I participated in a simulated EVA, or “Extra Vehicular Activity”. Like the Apollo astronauts who explored the surface of the Moon, the crew of HI-SEAS can only exit the safety of our habitat module wearing a spacesuit.
One of the most exciting aspects of participating in Mars and Lunar analog studies is the opportunity to test the use of spacesuits. Although it has been over 40 years since humans last walked on the surface of another world, NASA and a number of independent organizations have been busy developing new technologies to enable future explorers to traverse other planets.
Although we are still on Earth, the premise of this simulation demands that we treat the scenario as if this were a real space mission. That means we can’t open doors for a breath of fresh air. A certain level of mental adjustment has to be adhered to in order maintain the fidelity of the study.
The crew and I must conduct a number of EVAs throughout the duration of the mission. Some will be to study geologic features, or astronomical events, or even routine functions such as cycling the power on our hydrogen fuel cells.
We follow a strict set of procedures that are universal to the world’s various space programs. The whole crew assists those who are going outside in donning the suits. This is a challenge in itself. Before an astronaut -even a simulated one- can put on a spacesuit, we must test the radios, cooling fans, and the batteries that power them. The crewmember wears athletic gear or long underwear and a liquid cooling garment, or LCG. This is a layer, in our case a vest, that is embedded with plastic tubing that moves cool water around the occupant of the spacesuit to prevent them from overheating. The batteries (which weigh 6 lbs each) also power a cooling fan that pipes fresh air into the various appendages for the same purpose.
The crewmember who is donning the suit is then helped into it by the others. When fully configured, the suits weigh approximately 50 lbs- considerable additional weight for anyone to be carrying on themselves in Earth’s gravity. It does take more than one person to help someone into the suits. Simple tasks like pulling on a pair of gloves or tying the laces on one’s boots becomes near impossible with the limited flexibility. We use simple hand-held radios with headsets that allow us to communicate between the suits and the habitat. Those are checked and secured to us before we finally pull the helmet down over our heads.
Unlike real spacesuits- which are inevitably heavier because of the materials, joints, and reduced gravity environment they are meant to operate in, ours do not pressurize. Instead, we have standard seams and the cooling fan recirculate ambient air. Although having pressurized suit would be more realistic, they would also be more dangerous (and expensive).
We don’t have a real airlock in our habitat- but we simulate the function by enclosing the entrance way and adhering to strict pressurization/de-pressurization protocols. We operate under the assumption of a 5 psi atmosphere in the habitat, rather than one at sea-level. This allows us only 5 minutes of pre-breathing in the airlock prior to an EVA, rather than 15 or more. (Easily simulated here at 8,000 feet elevation)
I enjoy hiking, and I have some experience on rough terrain. But the same activity in a spacesuit adds another world of difficulty. Climbing a small hill becomes straining. Your center of balance is much higher with the weight of the helmet and backpack. Even though the faceplate of the helmet offers incredible visibility, you lose your peripheral vision. The helmet is fixed as well and one must turn their entire torso to look in another direction. Bulky gloves restrict dexterity. (But will save your hands from laceration on sharp volcanic rocks) The cooling fans drown out the any ambient sound. And scratching your nose is out of the question.
Today’s EVA consisted of myself, the crew technologist Ross Lockwood, and the engineer Annie Caraccio. (More on the crew later) Our objective was to document the local terrain and describe the geomorphology. Ross brought along a Giga-pan camera which can be programmed to make 360 degree panoramic images. I carried my Nikon SLR, and Annie brought along a test instrument known as a geo-technical soil tool. The tool is designed for testing the petrological tension in soil on other planets.
We explored the vicinity of the site where our habitat sits. Immediately up slope from us in a long meandering fissure, roughly 50 feet tall, that consists of older, brittle lava deposits. On top of this feature is a depressed area that turned out be the a collapsed lava tube. Numerous pit craters are strung along the length – a significant hazard when wearing a spacesuit.
Even holding and manipulating a camera is chore. A few dozen photos – after scrambling about the jagged terrain- left me winded. But the excursion was a success, we acquired useful data from the instrument and managed some very impressive panoramic photos. Per my additional role as the mission geologist, I will prepare a report this week that describes the geomorphology of our “landing site”.
One last detail- to recognize the path that has brought me here, I carried with me one of my most symbolically valuable possessions on this EVA: my Air Force wings. My wings have taken all over this planet Earth- maybe one day they will help carry me to other worlds as well.