All Extra-Vehicular Activities (EVAs) at SAM are conducted in pressure suits (“space suits”). These fully functional “personal spaceships” have been tested underwater, in vacuum chambers, and in high altitude experiments. The physical challenges of wearing a pressure suit include limited mobility in a pressure suit, grasping and using tools, heat built-up and pooling condensate; dehydration, hunger, and yes, having to eliminate human waste if on a longer duration EVA. They provide very real psychological challenges too: being in a small, sealed space; knowing your air is coming through a long umbilical, and audio-only communication with your team who remains inside of SAM.
Basic Procedure
At the start of the EVA, the crew member to venture on an EVA enters the airlock from the Crew Quarters and with the help of one or more additional crew members, dons (puts on) the pressure suit. The umbilical that carries the pressurized air is connected and air flow is initiated to keep the suit cool. The glove cuff and neck ring seals are closed and checked for leaks. The suited crew member confirms both sending and receiving radio communications. When all systems are clear, the crew seals the interior hatch. The suited crew member opens the valve at the far end of the airlock and releases the interior pressure until it equals that of the exterior ambient. The rest of the SAM facility remains pressurized. When the pressure gauge reads zero pressure differential, the crew member opens the exterior airlock hatch and exists the SAM facility. The suited crew member walks from the airlock landing down to the Mars yard.
Two SAM staff are present for the entire EVA, standing by to assist. This is the ONLY part of the SAM analog experience in which the SAM staff are directly engaged due to the inherent dangers involved in breathing through an umbilical, physical exhaustion, and potential falls when wearing a pressurized suit.
Once the EVA is complete, the suited crew member returns to the airlock, closes the outer hatch, closes the valve, and gives the thumbs up to the crew who are watching through the inner airlock viewing portal. The crew in the Crew Quarters open valve and the cabin air moves into the airlock, equalizing the pressure. The interior airlock hatch is then removed.
The crew member returning from the EVA doffs (takes off) the suit with the assistance of their fellow crew members. They are returned, safe, and usually a bit smelly.
We are honored to have engaged Dr. Cameron Smith, professor of archaeology and anthropology at Portland State University and founder of Smith Aerospace Garments for the design and fabrication of two fully functional pressure suits for SAM, used from 2021 through mid 2024.
Since mid 2025 a new generation of suits was designed and fabricated by Kai Nevers, an Industrial Design student specializing in exploration garments. Working with the a pressure suit built by Dr. Smith as a foundation, coupled with an intensive investigation in the rich history of pressure suit designs for the past century, Nevers delivered to SAM a whole new breed of suit designed for solo don/doff, greater flexibility in size and comfort, use of applied shoe or boot, removable gloves through a sealed wrist cuff, and built-in harness for attachment to the SAM Reduced Gravity Simulator.