Nasa has unveiled a powered robotic exoskeleton, which it hopes will help astronauts stay healthier in space - by making it harder to walk.
The space agency likened its new X1 suit to that worn by the superhero Iron Man.
It said that as well as helping astronauts to exercise, it could also be used to help paraplegics walk here on Earth.
It also envisions a future where the suit will allow astronauts to lift heavy gear on the surface of other planets.
The suit was co-developed by Nasa and the Florida Institute for Human and Machine Cognition.
It weighs 57 pounds and can be used to both inhibit movement and make it easier. The exoskeleton is worn over the legs with the help of a harness, and has four motorised joints and six passive ones.
When set to 'inhibit', the suit resists against normal movement and helps astronauts who otherwise have to spend extended periods on special exercise equipment to avoid muscle wastage.
But the same technology in reverse would help other people walk for the first time.
Nasa added that it could theoretically be used to help astronauts carry heavy equipment on the surface of other planets.
It is a spin-off from the Robonaut 2 robot, currently on board the International Space Station.
Above: the X1 exoskeleton
"Robotics is playing a key role aboard the International Space Station and will continue to be critical as we move toward human exploration of deep space," said Michael Gazarik, director of NASA's Space Technology Program.
"What's extraordinary about space technology and our work with projects like Robonaut are the unexpected possibilities space tech spinoffs may have right here on Earth. It's exciting to see a NASA-developed technology that might one day help people with serious ambulatory needs begin to walk again."
The X1 is currently in an early stage of research and development, but Nasa is actively pursuing it for use both in space and on Earth.