Prosthetic mobility tested in zero gravity for inclusive space exploration

Prosthetic mobility tested in zero gravity for inclusive space exploration
by Erica Marchand
Paris, France (SPX) May 28, 2025

In a first for space medicine research, a lower limb prosthesis has been tested in microgravity during the European Space Agency's (ESA) latest parabolic flight campaign aboard the 'Zero G' aircraft.

ESA astronaut reserve John McFall, a through-knee amputee, put his prosthetic leg through a series of activities-squatting, walking, and running-across more than 90 parabolas over three separate flights. These maneuvers created repeated microgravity periods lasting 22 seconds each, replicating conditions aboard the International Space Station (ISS).

The test flights began on May 21, 2025, from Bordeaux, France, as part of ESA's 86th parabolic flight campaign. McFall played a central role as a subject matter expert in ESA's Fly! initiative, which investigates how to overcome the barriers that have traditionally excluded lower limb amputees from participating in extended space missions.

Equipped with a mechatronic "smart" knee and interchangeable components for daily use and athletic performance, McFall's prosthesis incorporates sensors that depend on gravity. The Fly! research team developed the Ampu-T2 experiment to evaluate how this advanced hardware performs in a weightless environment.

Researchers partnered with orthopedic technology company Ottobock to collect and refine performance data. Initial tests involved standing and walking, while subsequent flights examined running with variations in blade stiffness and knee resistance. A harness and elastic cords, mirroring ISS exercise gear, simulated the load forces needed to keep McFall grounded on the treadmill during microgravity.

The findings will guide the optimal prosthesis setup for conducting daily tasks aboard the ISS.

Beyond technical refinement, the research has broader health implications. On Earth, bone stress from walking maintains density, but astronauts face rapid bone and muscle loss in space. A treadmill, bicycle, and resistance device help mitigate these effects aboard the ISS. McFall's tests could lead to adaptive training protocols for prosthesis users in orbit, ensuring all astronauts stay healthy during missions and upon return to Earth.

Fly! exemplifies ESA's commitment to advancing inclusive space exploration and preparing for the diverse crews of tomorrow.