How much gravity is enough? Team studies how astronauts determine 'up' in space

Sep 03, 2014
International Space Station. Credits: ESA

Keeping upright in a low-gravity environment is not easy, and NASA documents abound with examples of astronauts falling on the lunar surface. Now, a new study by an international team of researchers led by York University professors Laurence Harris and Michael Jenkin, published today in PLOS ONE, suggests that the reason for all these moon mishaps might be because its gravity isn't sufficient to provide astronauts with unambiguous information on which way is "up".

"The perception of the relative orientation of oneself and the world is important not only to , but also for many other aspects of perception including recognizing faces and objects and predicting how objects are going to behave when dropped or thrown," says Harris. "Misinterpreting which way is up can lead to perceptual errors and threaten balance if a person uses an incorrect reference point to stabilize themselves."

Using a short-arm centrifuge provided by the European Space Agency, the international team simulated gravitational fields of different strengths, and used a York-invented perceptual test to measure the effectiveness of gravity in determining the perception of up. The team found that the threshold level of gravity needed to just influence a person's orientation judgment was about 15 per cent of the level found on Earth – very close to that on the moon.

The team also found that Martian gravity, at 38 per cent of that on Earth, should be sufficient for to orient themselves and maintain balance on any future manned missions to Mars.

"If the brain does not sense enough gravity to determine which way is up, astronauts may get disoriented, which can lead to errors like flipping switches the wrong way or moving the wrong way in an emergency," says Jenkin. "Therefore, it's crucial to understand how the direction of up is established and to establish the relative contribution of gravity to this direction before journeying to environments with levels different to that of Earth."

This work builds upon results obtained in long-duration microgravity by Harris and Jenkin and other members of York's Centre for Vision Research on board the International Space Station during the Bodies in the Space Environment project, funded by the Canadian Space Agency.

Explore further: ESA's weightless plants fly on a Dragon

More information: PLOS ONE, www.plosone.org/article/info%3… journal.pone.0106207

add to favorites email to friend print save as pdf

Related Stories

ESA's weightless plants fly on a Dragon

Apr 23, 2014

(Phys.org) —It is a race against time for ESA's Gravi-2 experiment following launch last Friday on the Dragon space ferry. Stowed in Dragon's cargo are lentil seeds that will be nurtured into life on the ...

Gravity changes along the Moon

Apr 06, 2012

Using detailed topographic information from NASA’s Lunar Reconnaissance Orbiter mission, Curtin’s Western Australian School of Mines (WASM) spatial scientists, Dr. Christian Hirt and Professor Will ...

Testing immune cells on the International Space Station

Apr 20, 2014

The human body is fine-tuned to Earth's gravity. A team headed by Professor Oliver Ullrich from the University of Zurich's Institute of Anatomy is now conducting an experiment on the International Space Station ...

Recommended for you

Why is Venus so horrible?

3 hours ago

Venus sucks. Seriously, it's the worst. The global temperature is as hot as an oven, the atmospheric pressure is 90 times Earth, and it rains sulfuric acid. Every part of the surface of Venus would kill you ...

Image: Christmas wrapping the Sentinel-3A antenna

6 hours ago

The moment a team of technicians, gowned like hospital surgeons, wraps the Sentinel-3A radar altimeter in multilayer insulation to protect it from the temperature extremes found in Earth orbit.

Video: Flying over Becquerel

6 hours ago

This latest release from the camera on ESA's Mars Express is a simulated flight over the Becquerel crater, showing large-scale deposits of sedimentary material.

Spinning up a dust devil on Mars

7 hours ago

Spinning up a dust devil in the thin air of Mars requires a stronger updraft than is needed to create a similar vortex on Earth, according to research at The University of Alabama in Huntsville (UAH).

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

Scottingham
not rated yet Sep 03, 2014
I'd really like to see a centrifugal torus in orbit one day.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.