Why can astronauts 'fly' in space?

Humans sense position and movement on the ground based on the condition of Earth's gravity. In zero-gravity space, will that sensory nerve be altered, warping perception?

Below ground, it is easy for us to sense where our limbs are, whether we are moving or standing still, falling or sitting upright, thanks to input from some of the body's balance sensing systems. .

But if you're in a vacuum, wearing virtual reality glasses or sitting in a moving car, you might get dizzy.

Astronaut Karen Nyberg on the International Space Station. (Photo: NASA).

Fortunately, astronauts can adapt to the microgravity environment while on an orbiting spacecraft. A recent study evaluated their ability to sense movement while in space or after returning to the ground and found no obvious changes.

The near absence of gravity easily alters our perception of motion, and astronauts also feel like they are moving faster in the cramped space of a ship with weightlessness. of body.

Still, they were able to accurately assess how far they traveled along the corridor in visual simulations, both during and after spaceflight.

One of the ways the human body detects changes in position, or movement, is through the movement of fluid contained within an organ deep in the ear. This is the vestibular system , which provides us with awareness of acceleration, tilt, and rotation.

In space, microgravity disrupts the vestibular system by removing some of the information it normally processes, which is the constant pull of gravity on Earth that helps us know which way is up. .

Normally, the vestibular system works at the same time as the visual system to sense distance, speed, and direction of movement. While in space orbit, astronauts feel less with the vestibular system in their ears, but in return they become more sensitive to visual information.

So how does this impact astronauts' perception of distance traveled in visual simulations during and after long-duration flights, and do changes in body position have a similar impact? to them or not?

Researchers tested 12 astronauts, 6 men and 6 women, before, during and after their year-long flights to the International Space Station (ISS) and compared their performance. theirs with 20 other people on Earth.

The results showed that immediately after the flights, the astronauts visually overestimated the distance in the lying position compared to the upright sitting position before the flight, but then this difference also disappeared. loss, their ability to evaluate returns to normal.

However, on average, their perception of the distance traveled along the virtual corridor in the simulation experiment did not change much during their time in space , 1 week after return and 3 weeks after their return. A month later when I returned it was still the same.

This result is also similar to previous scientific findings that astronauts do not have any difficulty in spatial orientation.

This is useful information in emergency situations when astronauts need to move quickly on the ISS to locate equipment or access emergency exits, and is also necessary for standard research. prepare for flights to send humans to the Moon that many countries are ambitiously undertaking.