Four astronauts are currently hurtling toward the Moon in a spacecraft no larger than two minivans. On the historic Artemis 2 mission, the secret to staying fit is a 13.6-kilogram device called the Flywheel Exercise Device, or FED.
As Commander Reid Wiseman, Pilot Victor Glover, Mission Specialists Christina Koch and Jeremy Hansen journey through deep space, they are using this miniaturised gym to combat the harsh effects of microgravity.
HOW DOES THE FLYWHEEL GYM WORK?
In the weightlessness of space, muscles and bones begin to weaken almost immediately because they no longer have to support the body against gravity.
To prevent this, the FED uses a cable-based system similar to a yo-yo.
When an astronaut pulls the cable, an internal wheel spins and stores energy.
As the user pulls back against the spin, the wheel creates a smooth and steady resistance.
This clever design allows the crew to perform heavy strength training without needing any actual weights, which would be impossible to use in the weightless environment of space.
The FED is a masterclass in space engineering. Unlike gyms on Earth that rely on heavy weights, the flywheel provides up to 180 kg of variable resistance using physics alone.
This allows the crew to perform squats, deadlifts, and rowing in an extremely cramped environment.
WHY IS EXERCISE VITAL FOR LUNAR MISSIONS?
Without a daily 30-minute workout, the crew would face rapid physical decline.
This mission is the first crewed flight beyond low-Earth orbit since Apollo 17 in 1972, meaning the stakes are incredibly high.
There is no quick way back to Earth for medical help, so keeping the heart and bones strong is a non-negotiable mission requirement.
WHAT IS DAILY LIFE LIKE INSIDE ORION?
Recent footage shows Victor Glover exercising while Jeremy Hansen prepares a chocolate pudding cake.
Life inside the Orion capsule is a constant act of multitasking. The crew sleeps in custom nooks to save space, and every movement is monitored by ground teams.
Even the act of breathing during a heavy workout affects the cabin air quality, as the life support system must work harder to scrub carbon dioxide and moisture.
This tiny gym is more than just fitness equipment.
It is a vital piece of technology that ensures humans can survive and thrive as they venture back to the Moon and eventually to Mars.
