Astronaut Piers Sellers during an STS-121 spacewalk in 2006 to demonstrate techniques on repairing the shuttle's heat shield. Credit: NASA

Have A Heart! This Organ Plays Shape-Shifter In Space, Leading To Mars Mission Questions

31 Mar , 2014 by

Could a long mission to Mars increase your risk of heart problems back on Earth? That’s something that scientists are trying to better understand after discovering that hearts become temporarily rounder in space, at least in a study of 12 astronauts.

The finding doesn’t appear to be a big surprise for cardiovascular scientists, however, who had the astronauts examine their hearts using ultrasound machines on the International Space Station as well as before and after spaceflight. The heart gets 9.4 percent more round, similar to models developed for the project, before returning to its normal shape on Earth.

“The heart doesn’t work as hard in space, which can cause a loss of muscle mass,” stated James Thomas, lead scientist for ultrasound at NASA, and senior author of the study. “That can have serious consequences after the return to Earth, so we’re looking into whether there are measures that can be taken to prevent or counteract that loss.”

Astronauts typically spend six months on the International Space Station. One year from now, NASA’s Scott Kelly and Roscomos’ Mikhail Kornienko are going to launch for a one-year mission. Spending months upon months in space leads to a host of problems upon returning to Earth. Your muscles get weaker, you’re more likely to pass out, and you’re at increased risk of bone fractures, among other problems.

NASA astronaut Norm Thagard exercises aboard the Russian Mir space station in 1995. Thagard was the first American to launch into space aboard a Soyuz and spent what was then a record-breaking 115 days in space. Credit: NASA

NASA astronaut Norm Thagard exercises aboard the Russian Mir space station in 1995. Thagard was the first American to launch into space aboard a Soyuz and spent what was then a record-breaking 115 days in space. Credit: NASA

A typical person on the space station spends two hours a day exercising just to ward off the worst of the effects. The researchers added that one remedy could be to add more exercises targeting the heart. This will be particularly important for missions that last 12 to 18 months or more — such as a Mars mission.

Studying astronauts in space could provide data on Earth-bound patients facing similar problems, the researchers said. Since the models that they made for astronauts were so congruent with reality, this gives the researchers confidence that they could create similar models for patients on Earth.

Conditions that could be considered include ischemic heart disease (the most common kind of heart disease and source of heart attacks), hypertrophic cardiomyopathy (thickened heart muscle)  and valvular heart disease (damage to one of the heart’s valves).

Results were presented last week at the American College of Cardiology’s annual conference. It’s not immediately clear from a press release if the study was peer-reviewed. The researchers added that more study of astronauts after returning to Earth could be a useful research direction, to see how the effects persist (if at all.)

Source: American College of Cardiology

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FarAwayLongAgo
Member
FarAwayLongAgo
March 31, 2014 4:00 PM
No, this is in no way a problem for Mars missions! It is only a problem which has been invented by the ISS mission in LEO. A Mars mission would of course implement a long radius centrifuge in order to, by very simple mechanical means, eliminate all of the severe medical problems which astronauts on the ISS are today subjected to. To keep on researching how very harmful microgravity is in the long run, contributes nothing at all to the human exploration of space, since the problem of long term microgravity never needs to exist in the human exploration of space. (And of course never exists as a health problem on Earth!) Wire Cable Airbeam There are many… Read more »
Yoweigh
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Yoweigh
March 31, 2014 5:25 PM

Instead of learning how to live in microgravity we should just rely on a “simple and cheap” technology that has never been deployed in space before? How much is this long radius centrifuge going to weigh? How will it be launched? How will it be assembled in orbit? How will it be accelerated? What type of bearings will be used? How will they be maintained during transit?

It’s only simple from your armchair, and it’s only cheap in your imagination.

FarAwayLongAgo
Member
FarAwayLongAgo
April 1, 2014 1:54 AM

Yes, it’s absurd that NASA never has developed the practical details of centrifugal “gravity”! Instead they keep discovering more and more unsolvable medical problems with microgravity. It’s time to leave what has been proven to be impossible, and look for solutions instead.

mewo
Member
mewo
March 31, 2014 6:41 PM

One of the best ways to learn about something is to expose it to different conditions to see how it reacts. I can pretty much guarantee that studying how astronauts’ hearts change in microgravity will yield new insights into the circulatory system that will benefit medicine here on Earth.

FarAwayLongAgo
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FarAwayLongAgo
April 1, 2014 1:55 AM

Yes, it’s medical research, but it is not space exploration.

mewo
Member
mewo
April 1, 2014 2:20 AM

You said we shouldn’t study “unnecessary” medical problems. I gave a reason why we should. Microgravity is something meriting study in its own right.

FarAwayLongAgo
Member
FarAwayLongAgo
April 1, 2014 7:52 AM

Even for medical research, it would be much more interesting to study partial gravity. I’d suggest a space station which rotates with modules at different distances from the center of rotation to simulate Moon’s gravity (0.17g), Mars’ gravity (0.38g) and twice Earth’s gravity (2g). That’d also be the relevant range for any likely rocky/icy bodies with useful gravity. It’d be useful for preparing Mars exploration, which this blog post says that microgravity prevents.

frankg
Member
frankg
March 31, 2014 7:15 PM
It’s a sad day when no one looks at the reason their pet ‘solution’ isn’t implemented by NASA. NASA isn’t doing any research on spinning space ships because it doesn’t work. Think of how you walk on Earth. It’s been likened to a controlled fall. Gravity is one of the weakest forces in nature. It is so weak, that humans (and other creatures) can overcome it by simply jumping. When we cease contact with the Earth and can no longer impart energy into the jump, then, and only then, does the mass of the Earth bleed off the energy to the point where the body is attracted back to the surface. This is exactly what we do when… Read more »
mewo
Member
mewo
April 1, 2014 2:00 AM
You are completely wrong about the spinning spacecraft, and I will prove it mathematically. Suppose we have a spinning spacecaft in the shape of a circle with some radius R, such that all the points on the circle are moving with speed V_H. Imagine I am standing on the inside of the circle, and you’re outside the spaceship, stationary, looking in at me. Now, from my point of view, I am going to jump straight up towards the center of the circle with a speed V_J. So from your point of view I am travelling both horizontally (with speed V_H) and vertically (with speed V_J) and, since I am no longer touching anything and no forces are being… Read more »
frankg
Member
frankg
April 1, 2014 10:16 AM
Mewo, You’re the one that doesn’t understand the process. As I said, your muscles are strong enough to overcome the pull of gravity here on Earth. Your angular momentum ‘gravity’ imparts nothing different to your body as long as you stay in contact with the vessel. Take one normal step, however, breaking the pull of your spinning ‘gravity’ and without a mass to bring you back down you’re going to bounce around inside your vessel. I’ll even go out on a limb here and say that if you stand inside a spinning space ship and pull your legs up into a lotus position you won’t ‘fall’ but probably drift towards a rear bulkhead. And if your spinning worked,… Read more »
EmeraldRayJr
Member
EmeraldRayJr
April 1, 2014 5:34 PM
frankg, “I’ll even go out on a limb here and say that if you stand inside a spinning space ship and pull your legs up into a lotus position you won’t ‘fall’ but probably drift towards a rear bulkhead.” Wrong. Mewo had it correct. Since you don’t understand vectors in math, let’s try a visual representation. In the spinning spaceship in space, you are moving at a certain speed. If the spaceship floor disappeared, you would continue to move at that same speed in a “straight line” at the moment the floor disappeared. However, the spinning floor keeps turning, like turning in a vehicle, which throws you towards the floor. Lift your legs, and you will continue to… Read more »
frankg
Member
frankg
April 1, 2014 7:36 PM
“In the spinning spaceship in space, you are moving at a certain speed. If the spaceship floor disappeared, you would continue to move at that same speed in a “straight line” at the moment the floor disappeared.” Right so far. What you are forgetting is that when you attempt to walk the energy imparted by the angular momentum is neutralized by the muscular input of your legs. I’ll concede that you may need to impart a bit of a jump up before pulling your legs up into my lotus position example but it still comes down to the fact that the angular momentum is only imparted to your body as long as you stay in one spot or,… Read more »
EmeraldRayJr
Member
EmeraldRayJr
April 2, 2014 1:51 AM
I do agree with the 1-g propulsion unit as it reduces time in space which is full of harmful radiation. Where we disagree is that generating artificial gravity using centripetal force is also an alternative and it will work to alleviate some of the health problems of humans in weightlessness. Since I’m not an expert, I looked for articles that explained where NASA is with artificial gravity. NASA dropped and then brought back artificial gravity research due to changing priorities and funding. Astronaut Michael Barratt does a really great job explaining artificial gravity and why NASA hasn’t build a spinning space ship yet (mainly because it is very expensive to build a ship large enough to create a… Read more »
frankg
Member
frankg
April 2, 2014 8:14 PM
I, just like NASA, have no empirical evidence that spinning either works or doesn’t work. But, after looking at how humans walk and all of the elements of walking, it becomes obvious that, when we walk or do anything, we rely on and interact with the mass of the Earth . Looking at what we know of gravity it’s obvious that we easily overcome it with every motion including walking. As noted by many physicists, gravity is the weakest of all of the elemental forces of nature but it is also the most pervasive. Of all of the environmental factors involved in the evolution of life on this planet only gravity has remained the same; the mass of… Read more »
Cosselbray
Member
Cosselbray
April 5, 2014 3:31 PM

Just a thought: How about small spinning sleeping areas; several hours of the day are spent sleeping, there would be no need to walk around and it would not be required in other areas of the spacecraft. Data could be collected to determine the benefit or otherwise of 1g, 0.5g (2g?) to enable medical and engineering decisions to be made. As I have a medical background, speculation as to the design is left to the engineers.

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