When using Vection, the astronauts are guided through three tasks via a head-mounted display. In the first, they are accelerated “sideways” along a virtual corridor, triggering a sense of motion even though in reality they remain still.
“We then assess whether any of that visual acceleration may be interpreted as acceleration due to gravity by asking them to indicate the new angle of the floor, which should appear tilted if they regard their previous direction of motion as ‘up’,” Harris said.
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In the second experiment, astronauts view a target in the same corridor. The target disappears as the astronauts virtually “move” along the corridor, and they press a button when they reach the position where they think that the target was situated.
“This tells us about how powerful visual motion is in space: how far visual motion makes you feel you have moved,” Harris explained.
The third experiment asks astronauts to compare the size of an object in the virtual corridor with a reference object they have in their hands. “The only way they can assess an object’s size is by knowing how far away it is and therefore this allows us to measure their perceived depth,” Harris added.
This work not only has implications for the ISS, but any future spaceflight activity – including NASA’s desire to establish the Lunar Orbital Platform-Gateway space station near the moon in the 2020s, and to move crews to Mars in the decades that follow. Knowing depth perception in space can help astronauts improve their ability to reach emergency hatches, dock a spacecraft, or control robotics platforms.
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