NASA’s down-to-Earth approach to balance

NASA is developing a training device to help astronauts readjust to the Earth’s gravity after completing long missions, as well as keeping them fit while in space.

Travel to other planets or manning the International Space Station involves astronauts spending long periods in space in zero gravity. Over time this causes bone wastage, and bloodflow and digestion problems in humans, as well as difficulty maintaining balance lasting several weeks once the astronaut is back.

To counter this, the Texas-based US National Space Biomedical Research Institute (NSBRI), a consortium of NASA-funded institutions studying the health risks of long-duration space flight, is working to create a treadmill-based virtual reality system that will shorten or remove post-flight balance problems. Astronauts will dodge obstacles on the virtual reality screen as they move along the treadmill, which will change gradient in concert with the images.

‘We anticipate the finished item will consist of a virtual reality environment like a bubble containing the treadmill and a hemispherical screen,’ said Dr Jacob Bloomberg, a researcher with the NSBRI’s neurovestibular adaptation team and a senior researcher at NASA’s Johnson Space Centre.

As well as preventing deterioration of muscles including the heart, the system will train astronauts’ brains to be adaptive and so able to cope with the return of gravity. ‘The idea is to challenge the brain, teaching it to adapt,’ said Bloomberg.

The researchers, who hope the device will allow astronauts to take part in lengthy manned missions, are examining how multiple systems in the body’s sensory and motor system work to maintain balance during normal behaviour such as walking, to develop the training unit.

While walking on the treadmill, test subjects’ head, eye and body movements are recorded using a video-based motion capture system while sensors record body accelerations and the vertical forces that occur during each footfall.

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