Note: Single-source report; awaiting corroboration.
The Artemis II astronauts relied on a compact exercise device called the flywheel during their 10-day, 694,481-mile journey around the Moon and back. The device helped them maintain physical and mental health aboard the Orion spacecraft.
Ryan Schulte, Orion flywheel project manager at NASA's Johnson Space Center, led the team that designed, built, tested, and flew this multi-functional device. The flywheel, about the size of a large shoebox, allows crew members to perform a range of aerobic and resistive workouts without drawing electrical power from the spacecraft.
According to Schulte, the flywheel works like an inertial yo-yo and offers adjustable resistance through different gear ratios, providing up to 500 pounds of resistance depending on user effort. Crew members could perform exercises such as squats, deadlifts, bent rows, high-pulls, curls, heel raises, and aerobic rowing, all with the same device.
The design faced challenges such as limited space inside the capsule, ensuring crew mobility, and reducing noise to maintain clear communication during workouts. Schulte highlighted how difficult it was to create a compact device that still allowed astronauts to stand fully and extend movements at high speed and repetition.
Exercise sessions of about 30 minutes daily helped combat the effects of microgravity, which can weaken muscles, bones, and stamina. Schulte noted that maintaining physical fitness is critical to prevent injury during lunar surface activities or emergency situations, and also supports mental health by providing stress relief and mental clarity amid the confined environment of the spacecraft.
The flywheel developed for Artemis II is part of NASA's continued effort to create reusable exercise equipment for future Artemis missions.