France24
Paris (AFP) – Astronauts lose decades’ worth of bone mass in space that many do not recover even after a year back on Earth, researchers said Thursday, warning that it could be a “big concern” for future missions to Mars.
Previous research has shown astronauts lose between one to two percent of bone density for every month spent in space, as the lack of gravity takes the pressure off their legs when it comes to standing and walking.
To find out how astronauts recover once their feet are back on the ground, a new study scanned the wrists and ankles of 17 astronauts before, during and after a stay on the International Space Station.
The bone density lost by astronauts was equivalent to how much they would shed in several decades if they were back on Earth, said study co-author Steven Boyd of Canada’s University of Calgary and director of the McCaig Institute for Bone and Joint Health.
The researchers found that the shinbone density of nine of the astronauts had not fully recovered after a year on Earth — and were still lacking around a decade’s worth of bone mass.
The astronauts who went on the longest missions, which ranged from four to seven months on the ISS, were the slowest to recover.
“The longer you spend in space, the more bone you lose,” Boyd told AFP.
Boyd said it is a “big concern” for planned for future missions to Mars, which could see astronauts spend years in space.
“Will it continue to get worse over time or not? We don’t know,” he said.
“It’s possible we hit a steady state after a while, or it’s possible that we continue to lose bone. But I can’t imagine that we’d continue to lose it until there’s nothing left.”
A 2020 modelling study predicted that over a three-year spaceflight to Mars, 33 percent of astronauts would be at risk of osteoporosis.
Boyd said some answers could come from research currently being carried out on astronauts who spent at least a year onboard the ISS.
Guillemette Gauquelin-Koch, the head of medicine research at France’s CNES space agency, said that the weightlessness experienced in space is “most drastic physical inactivity there is”.
“Even with two hours of sport a day, it is like you are bedridden for the other 22 hours,” said the doctor, who was not part of the study.
“It will not be easy for the crew to set foot on Martian soil when they arrive — it’s very disabling.”
‘The silent disease’
The new study, which was published in Scientific Reports, also showed how spaceflight alters the structure of bones themselves.
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Going off on a tangent here, the tangent being that it's pretty unlikely we'll ever go to mars, and I'd say even going to the moon (again?) may be unlikely.
Just a few days I got the itch to see what was behind the theory that the moon landings were a hoax. It was quite difficult to find any pro-hoax websites. They are out there, but web searches (google AND duck duck go) will turn up nothing unless you include some aspect of a moon hoax theory, one that doesn't show up in "debunker" websites. Anyway, I got really suspicious, considering how much work went into making it impossible to find pro-hoax websites.
One website with a lot of good science based information is https://www.aulis.com/nasa2.htm
There's just so many things wrong...
Space X's difficulty with vertical landings really show how the landings of the moon had to be faked. For six attempts to land vertically on the moon, with no gyroscopes, no computers, no practice. And Space X's attempts failed 5 times with much better equipment.
Deadly radiation in the Van Allen belts, no shielding. The rockets were very underpowered. Many, many problems with photos. Videos look like they were filmed on the earth if you just speed them up some...it's just sad.