Centrifuge research on ISS suggests some artificial gravity can mitigate negative effects of weightlessness
When I appeared on the Space Show last month I stated something about centrifuge research that was wrong. I had been under the false impression that no such research had yet been done on ISS, and our only data came from one experiment performed by the Soviets on one of their early space stations decades ago.
Charles Lurio, who writes the very respected Lurio Report newsletter on space matters, called me afterward to correct me, and then followed up by sending me a link to a paper describing research on ISS in the past few years using rats inside three different small centrifuges (two of which are shown in the picture to the right). For this information I thank him.
You can download the paper here [pdf]. The research is significant because it suggests that the medical problems of weightlessness can be solved by creating an artificial gravity far less the Earth’s 1g environment. From the paper’s abstract:
We recently developed a multiple artificial-gravity research system (MARS), which can generate gravity ranging from micro-gravity to Earth gravity (1 g) in space. Using the MARS, we studied the effects of three different gravitational levels (microgravity, lunar gravity [1/6 g], and 1 g) on the skeletal muscle mass and myofiber constitution in mice.
All mice survived and returned to Earth, and skeletal muscle was collected two days after landing. We observed that microgravity-induced soleus muscle atrophy was prevented by lunar gravity. However, lunar gravity failed to prevent the slow-to-fast myofiber transition in the soleus muscle in space. These results suggest that lunar gravity is enough to maintain proteostasis, but a greater gravitational force is required to prevent the myofiber type transition. Our study proposes that different gravitational thresholds may be required for skeletal muscle adaptation. [emphasis mine]
The results proved that the Moon’s gravity, 16% of Earth’s, is sufficient to prevent certain forms of muscle atrophy. And while it was not sufficient to prevent other muscle atrophy, the data suggests that inducing an artificial gravity less than Earth’s might still work.
Creating an interplanetary space ship that has a 1g environment is a major engineering challenge. If you could build it and only have to provide 1/2g, or even 1/3g, you simplify the engineering significantly. The structure won’t have to spin as fast, which means its structure doesn’t have to be built as strong. That lowers its weight, which also lowers the cost because less material needs to be launched into space.
This research is only preliminary, and is very uncertain. It however underlines the critical need to answer to this question: What is the minimum artificial gravity required to prevent bone-loss and muscle atrophy?
Though it might be possible for further ISS research with these small centrifuges to refine the question somewhat, I suspect the real answers won’t come until people are living for three to six month periods on the Moon. Which also means the Chinese are likely going to get the answer before us, because I fully expect their lunar base to be operational before NASA’s Artemis program gets off the ground.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
When I appeared on the Space Show last month I stated something about centrifuge research that was wrong. I had been under the false impression that no such research had yet been done on ISS, and our only data came from one experiment performed by the Soviets on one of their early space stations decades ago.
Charles Lurio, who writes the very respected Lurio Report newsletter on space matters, called me afterward to correct me, and then followed up by sending me a link to a paper describing research on ISS in the past few years using rats inside three different small centrifuges (two of which are shown in the picture to the right). For this information I thank him.
You can download the paper here [pdf]. The research is significant because it suggests that the medical problems of weightlessness can be solved by creating an artificial gravity far less the Earth’s 1g environment. From the paper’s abstract:
We recently developed a multiple artificial-gravity research system (MARS), which can generate gravity ranging from micro-gravity to Earth gravity (1 g) in space. Using the MARS, we studied the effects of three different gravitational levels (microgravity, lunar gravity [1/6 g], and 1 g) on the skeletal muscle mass and myofiber constitution in mice.
All mice survived and returned to Earth, and skeletal muscle was collected two days after landing. We observed that microgravity-induced soleus muscle atrophy was prevented by lunar gravity. However, lunar gravity failed to prevent the slow-to-fast myofiber transition in the soleus muscle in space. These results suggest that lunar gravity is enough to maintain proteostasis, but a greater gravitational force is required to prevent the myofiber type transition. Our study proposes that different gravitational thresholds may be required for skeletal muscle adaptation. [emphasis mine]
The results proved that the Moon’s gravity, 16% of Earth’s, is sufficient to prevent certain forms of muscle atrophy. And while it was not sufficient to prevent other muscle atrophy, the data suggests that inducing an artificial gravity less than Earth’s might still work.
Creating an interplanetary space ship that has a 1g environment is a major engineering challenge. If you could build it and only have to provide 1/2g, or even 1/3g, you simplify the engineering significantly. The structure won’t have to spin as fast, which means its structure doesn’t have to be built as strong. That lowers its weight, which also lowers the cost because less material needs to be launched into space.
This research is only preliminary, and is very uncertain. It however underlines the critical need to answer to this question: What is the minimum artificial gravity required to prevent bone-loss and muscle atrophy?
Though it might be possible for further ISS research with these small centrifuges to refine the question somewhat, I suspect the real answers won’t come until people are living for three to six month periods on the Moon. Which also means the Chinese are likely going to get the answer before us, because I fully expect their lunar base to be operational before NASA’s Artemis program gets off the ground.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Great to hear that someone actually got data on this problem!
Interesting. I am not a biologist nor do I have a medical background in medicine.
So I do not follow all of this, but slow to fast transition.. is this implying that one of the effects of microgravity is that slow twitch muscles convert or transition to fast twitch muscles?
I skimmed through and did not see, but also did not expect, any suggestion if the addition of heavy workouts in 1/6th could mitigate or delay this transition. It was not part of the study and would have been speculation, I imagine.
The bigger question for me is, does that mean that long duration stays on the Moon, properly sheltered from radiation, are less impactful on the human body.
I guess the only real way to discover this would be to set up a permanent base.
sippin_bourbon: Reread the last paragraph of my post.
A variable g space station in LEO will get the data. Starship should be able to launch one in the next couple of years.
This paper is however, good news. However also, rats is not people.
I think…..
Its not actually a cellular conversion from fast twitch to slow twitch muscles but just the conversion from using high mitochondria high energy production to low mitochondria anaerobic glycolysis for energy production.
It more than likely a result of just the lower gravity. The muscle does not need to work that hard and so it switches to a lower energy system.
In my personal opinion if they could have made the mice exercise they might not have converted. People could and would do more work than just sit in a spinning cage.
My real worry is with the cerebral spinal fluid. It is moved in a large part by gravity and in low gravity it does not flow out of the brain as fast and causes the eye fluid to change pressure and eye shape. All astronauts end up needed glasses in space. Their spines lengthen also. And it has now been connected with the removal of waste products from the brain which if they are not removed fast enough they leave behind something( can not remember) something that causes dementia and other mental age related problems.
In the end the closer to one G the better. We have had a few million years to get used to it. To need it.
Great information on ISS research that I did not know was going on.
Lower spin rates are also easier for the human ear to adapt into.
Very interesting.
Thank you
Thanks for this—had no idea any such research had been conducted.
It’s about time for these kind of things to get some serious attention (money).
The Japanese centrifuge module which was put together to answer these questions was cancelled nearly 20 years ago after being built because NASA needed funding for Shuttle and gutted Biosciences along with other science directorates.
pzatchok
You may have a calling if you can train the rodents to use elastic bands or perform isometrics.
I was thinking about TaiChi.
Simple physics would suggest we knew this already. Nice to have “proof” I suppose…
For astronaut health I’d question side-effects of rotation. Coriolis of course; also blood circulation in a corpus at rest – like, during sleep or (more so) longterm hibernation if that happens.