Listen to Australian and world news and follow trending topics with SBS News Podcasts.
TRANSCRIPT
The recent Artemis II mission to fly past the moon gripped the imaginations of millions.
They listened in as ground control - and a range of political figures like Texas Senator Ted Cruz - talked with the crew of four astronauts, as items floated around the cabin.
"What would you tell yourself about going to the moon? And then question two, if and when they make a movie about this, who do you want to play you? "
NASA is also part of the International Space Station, which is permanently in orbit around the earth with revolving crews on board.
They do space walks on a regular basis to conduct repairs and experiments.
NASA UPSOT GROUND CONTROL: "Today's spacewalk is the third for McLean, and the first for ((Nicole)) Ayers."
In each case, these floating objects - and astronauts - are one of the most visible lessons about how science works in space, and how crew members do simple tasks like hold on to objects.
On Earth, people grip things so as not to drop them but in space, where there is no gravity, objects float when released.
Philippe Lefèvre is a Professor of Biomedical Engineering at Université Catholique de Louvain and Ikerbasque.
He says those forces are why astronauts have to hold items differently.
"When you are on board the ISS in weightlessness, the movement becomes symmetric because there is no more effect of gravity. So which means that you have to squeeze as much when you’re at the top than when you are on the bottom, which is not the case on Earth."
The professor is the lead author of a new study that has just been published in the Journal of Neuroscience, looking at how astronauts adapt their grip in these very different environments.
They found the brain keeps a lasting memory of gravity, even after months in space.
He says this effect was especially clear when objects were moving.
"The astronaut when they touch the object, there is no weight. The brain somehow overcompensates the expectation and so this is why they squeeze more."
For the study, researchers were able to test astronauts the day after they returned to Earth.
The team worked with 11 astronauts - finding they repeatedly made errors.
At first, they misjudged how strongly to hold objects, but they quickly adjusted back to normal behaviour.
"The first few movements, they were really still having memory of a weightlessness environment. So there was a potential hazard because they did not grip the object optimally. But what was very interesting is that after a few tenths of repetitions, they recovered the normal behaviour. What this shows is that when they return back to Earth, they relearn the Earth environment much faster than they learn the microgravity environment."
The researchers say they're hoping to publish more data collected from astronauts, including on adjustments following a collision with an object.
But the research could have implications for future missions, especially longer ones to the Moon or Mars.
"If we prepare astronauts to land on the Moon, for instance - in that case, they might need some specific training, because the way they are going to manipulate objects might be affected by partial gravity. So they might need some training on Earth just to make them adapt to a partial gravity environment. But that’s another question, of course. That’s for the future plans."
