John McFall, a former Paralympic athlete and orthopaedic surgeon, was selected as the first member of the European Space Agency's (ESA) Astronaut Reserve with a physical disability in 2022. His selection marked a historic step in ESA's Fly! initiative, which explores the feasibility of including astronauts with disabilities in long-duration missions to the International Space Station (ISS).
The Feasibility Study phase of Fly! examines the challenges related to McFall's lower limb amputation and aims to develop solutions for spaceflight adaptation, fitness, and prosthetic technology in microgravity. McFall participated in a fluid shift investigation at :envihab, a specialized research facility at the German Aerospace Agency's Institute of Aerospace Medicine.
In microgravity, body fluids shift headward, causing astronauts to experience a 5-10% reduction in lower leg volume shortly after entering space. This study investigated similar volume shifts in an amputated limb and their potential impact on prosthesis fit and comfort during spaceflight.
To simulate microgravity effects, McFall underwent tilt-table testing and moderate-intensity cycling in a head-down position, measuring volume changes in his stump. The results indicated that no adjustments to his prosthesis would be necessary for future missions.
Fly! represents ESA's commitment to increasing diversity in human spaceflight, expanding its astronaut talent pool, and enhancing accessibility in space exploration. McFall's expertise and involvement provide critical insights as ESA aims to make space missions inclusive for all.