Tamara Franz-Odendaal has been researching how space travel affects the human skeleton for twenty years.
Due to the lack of gravity in space, astronauts experience bone loss when they return to Earth.
“We always think of it as a scaffolding that holds the body together, but it’s really a dynamic tissue,” said Franz-Odendaal, a professor at Mount Saint Vincent University.
Franz-Odendaal is leading a two-year research project to better understand how bones respond to the lack of gravity, using a device known as a random positioning machine that simulates microgravity experiments on Earth. The research has implications for improving the treatment of bone disorders such as osteoporosis.
Franz-Odendaal’s research uses zebrafish placed on a platform and then randomly rotated to simulate zero gravity.
This device, known as a random positioning machine, is used to simulate the lack of gravity in space. (Submitted by Tamara Franz-Odendaal)
Zebrafish are widely used as a model organism in developmental biology, he said, and “are actually used as models for many human diseases because their cell types are so similar, and this also applies to the skeleton.”
Canadian astronaut David Saint-Jacques has firsthand knowledge of bone loss after space missions. He spoke to CBC News from the Canadian Space Agency’s headquarters in Longueuil, Que. Saint-Jacques went to the International Space Station for a 204-day mission starting in late 2018.
Canadian Space Agency astronaut David Saint-Jacques, one of the main crew members of the International Space Station expedition, gestures before the launch of the Soyuz MS-11 spacecraft to Kazakhstan on December 3, 2018. (Dmitri Lovetsky/The Associated Press)
People may imagine astronauts walking triumphantly as they return to Earth, but that’s not the reality.
“It’s so frustrating,” he said, “because you think it’s like riding a bike. ‘Hey, I’m going to be an earthling again.’ “No, readjusting to gravity is harder than adapting to space, even though it’s your first time there and evolution hasn’t prepared us for it.”
Photos from his return in 2019 show him being carried by others.
Ground personnel help Saint-Jacques exit the Soyuz MS-11 capsule shortly after landing in a remote area outside Zhezkazgan, Kazakhstan, on June 25, 2019. (Alexander Nemenov/AFP via Getty Images)
He lost his sense of balance during the mission and was prone to fainting because space altered his blood flow.
Since there is no gravity in space, blood flows equally to different parts of the body. On Earth, more of this needs to go to the brain, but proper blood flow doesn’t return immediately.
‘Perfect guinea pigs for medical research’
Saint-Jacques, who was a doctor before becoming an astronaut, said that the changes astronauts experience in their bodies in space make them ideal for medical research.
“These occur very quickly and in very young individuals who are in excellent condition,” he said. “We are the perfect guinea pigs for medical research.”
Saint-Jacques also said it’s easier to study these changes because astronauts don’t have other medical conditions, unlike an elderly person with a variety of health problems.
Astronauts get a lot of exercise in space, Saint-Jacques said.
Ground personnel transport Saint-Jacques after his return to Earth. (Alexander Nemenov/AFP via Getty Images)
“Since nothing has weight, if we’re not careful, you’re not using your bones that much,” he said. “So if you’re not careful, they’ll get very weak. That’s why we do so much exercise in space.”
Despite the exercise, astronauts have trouble adjusting to life on Earth. He said it took months for him to return to normal and that he could resume hobbies such as playing basketball and skiing.
“I was there [Earth] “My ancestors have been the same throughout my life, they should return this way,” he said.
“That’s not how it works.”
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