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.
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
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!)
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There are many simple and cheap ways to avoid the medical dangers of microgravity. We should study those mechanical technologies instead of studying unnecessary medical problems.
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.
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.
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.
Yes, it’s medical research, but it is not space exploration.
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.
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.
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 we walk or run. We – and every other creature that locomotes like us – rely on the mass of the Earth to work with our muscles to push us up just enough during our ‘fall’ forward, to bring our trailing leg forward to catch us before we fall on our face. With evolution’s adaptations we, and all of the other creatures on this Earth are able to move effortlessly around.
When you are inside a spinning spacecraft simulating 1-g, as long as you don’t move and stay in contact with the ‘floor’ you should (remember, no one has ever done this in zero g) experience ‘weight’. Take one normal Earth-like step and, with no mass to attract you back down, you’ll bounce around the inside of the vehicle like a pea in a baby’s rattle.
Once again: spinning a spaceship does not work. Turn off the sci-fi, learn real physics and stop being a twit that thinks science should be just like science fiction.
And no one is going to Mars if it takes 6 months (or more) of freefall to get there. Astronaut stays of six months on ISS should make that abundantly clear.
A potential solution to a mission to Mars is to develop (and this won’t be easy or cheap) a propulsion system that will accelerate a mission viable mass to the Red Planet at 1-g. As Einstein note in 1907 in his paper on the Equivalency Principle (http://en.wikipedia.org/wiki/Equivalence_principle), there’s no difference between accelerative and inertial gravity from the standpoint of the body affected.
And a bonus using a propulsion system generating 1-g acceleration? You are at Mars in a day and a half. Yep. Do the math: 36 hours +/-.
This has several obvious benefits:
*You only have to pack life support for 3 days of flight, your stay at Mars and, of course a contingency supply resulting in a simpler mission.
*You can have a second ship on immediate standby to rescue a stricken vessel within a window of several days should that be required. In other words, a mission can be easily rescued.
*Almost no exposure to micro-gravity except in Mars orbit.
*Very limited exposure to a severe radiation environment in interplanetary space
*No psychological effects from a long period cooped up in a tin can.
*Current technology will reliably support such a short mission (No one will guarantee a perfect system and subsystem operation for a 3 year mission).
Related benefits are that such a propulsion system can be utilized by unmanned probes to get to every destination in the solar system in a very short flight. Jupiter is about 10 days flight time. Pluto is about 30 days flight time. And when you get to where you’re going, you drop off your probe, loop back to Earth, refurb your propulsion system and go do it again. That’s about as green as it gets.
Are there issues with such a system? You bet! We’re talking about magnetic confinement not unlike fusion reactors. We’re talking about megawatt power supplies and high power nuclear reactors. We’re talking about speeds that are not an insignificant percentage of light speed. We’re talking about technology that is going to be enormously difficult to develop and bring to operational status. But it’s the only way we’ll get a manned mission to Mars. A ballistic trajectory will return dead astronauts if anything at all.
So, get over spinning a space ship. It’s as silly as a space elevator … and like the elevator, it doesn’t work. Whether you like it or not, physics is always the limiting factor and it would behoove you to understand it before you pop off with nonsense that insults the engineers at NASA that have to deal with the ‘non-fiction’ science of getting to Mars.
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 applied to me, I continue with that speed in a straight line. Now, clearly that path intersects the circle again. Which means, from my point of view, I jump and then some time later I land. It doesn’t matter that there is no mass to pull me back down. I will hit the ground again.
Also, your math about the trip to Mars is wrong by a factor of four because you forgot that you have to slow down as well. Assuming the distance from Earth to Mars is 80 million kilometers (which is as close as they ever get), you have to do the first 40 speeding up at 1g acceleration. That will take 3.2 days, using the basic equation of motion d=at^2/2. Then you have to do the second half decelerating at 1g. That’s another 3.2 days by symmetry. If you accelerate the whole way at 1g you can get there in a mere 4.6 days, but you’ll hit the planet at about nine million miles an hour.
Honestly, if you’re going to berate people about science, you need to show better than a junior high grasp of the subject.
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, what would happen if you ‘walked’ in the direction of the spin or, turned around, and walked against the spin? No one has ever been inside a spinning spacecraft in zero g such that they can walk around. The closest anyone has come is when they tried to spin a Gemini spacecraft with questionable results. I’m sorry, Mewo, spinning does not work except in science fiction and you really need to put the sci-fi down and look at the real physics that NASA’s engineers are dealing with.
And even if it did work, the engineering would be prohibitive and unworkable. If you had a 10-person crew at 200 lbs each and the commander called a meeting, how do you balance a ton of mass all converging on one spot of your spaceship? How do you rebalance your ship? As the crew moves around how do you actively rebalance? A few grams out of balance on much smaller NASA unmanned probes has resulted in loss of vehicles. What do you think would be the consequences to an exponentially larger, and structurally delicate, vehicle with a constantly shifting center of gravity?
And, if spinning worked and you could convince NASA to build it, your ship would be huge. It took NASA and its partners 11 years to build ISS and that was basically a snap-together-and-plug-in-the-wires process. And we had a 60 x 15 foot cargo bay to haul up components and support the construction. What construction/support craft are you willing to spend money on for a spaceship that will rival the ISS in size … if spinning worked.
And if spinning worked for your Mars mission, you’ve still got 6 months (or more) transit times, the psychological issues, the radiation exposure, a huge life support supply and storage issue, MTBF (mean time between failure) issues with all of the systems and subsystems and no possibility of rescue should something likely happen that jeopardizes the crew. Getting to Mars as quickly as possible is the only way humanity will successfully get to Mars.
As for the day and a half trip to Mars at 1-g acceleration, I had math professors at the UNC-Chapel Hill do the math. Give or take a few hours, it is, indeed, ~36 hours to Mars. That includes accelerating for the first half, basically an instant turn-around to begin decelerating (an unlikely process but, for the sake of argument, I’ll assume it here), and decelerating the last half at 1-g. This all assumes the shortest distance and a straight line shot at Mars.
Here’s a website that calculates quicker times at 1-g acceleration to all of the planets. http://space.stackexchange.com/questions/840/how-fast-will-1g-get-you-there
In addressing one of the issues of a high speed transit, to avoid debris and dust in the plane of the ecliptic it might be advisable to arc up over the plane, taking a bit longer but avoiding a lot of impacts.
Your comments, Mewo?
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 move at that same speed in a “straight line” at the moment you lifted your legs. But the floor will change direction and curve inward. Your “straight line” will intersect the circle “floor of the spaceship” as both you and the floor move. From an outsider’s point of view, it looks like you and the floor are moving together. From an insider’s point of view, the floor where you were standing stays under you while you intersect the floor (float back down to it).
And, no NASA has not abandoned the spinning spaceship. It just is impractical at this time for other reasons. NASA is studying the use of astronaut-sized centrifuges. It is much easier to build something small, than a large spaceship to create artificial gravity. Just as it is impractical to use constant acceleration & deceleration because of fuel needs.
A nice article from Popular Mechanics explains why we don’t yet have artificial gravity. http://www.popularmechanics.com/science/space/rockets/why-dont-we-have-artificial-gravity-15425569
“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, perhaps, shuffle across the floor without lifting your feet as you would if you walked normally. The very act of walking as we do on Earth is to counteract gravity …. neutralize it with every step. Nothing changes in a spinning spaceship except that any attempt to walk normally will have no Earth-sized mass to interact with so you aren’t going to come ‘down’. Again, you’ll bounce around inside of the vehicle like a pea in a baby’s rattle.
Spinning a spacecraft to use angular momentum to generate artificial gravity doesn’t work no matter what you think your vector math is saying to you. You address one aspect of the problem with the math and then conveniently forget the rest of the problem, namely, no mass to interact with. The mass is absolutely essential for normal locomotion. You cancel the momentum when you walk normally or jump up.
You’re right, NASA is looking at spinning an astronaut in a bed-like device to put stress on the heart and bones to see if it can alleviate the wasting issues. It’s not the same thing as spinning a spaceship for artificial gravity where a crew can work in an ‘Earth-normal’ gravitational environment. It might work as a mitigation to wasting. However, a 1-g propulsion unit will definitely solve the wasting issues as well as many other engineering and medical issues.
As for a 1-g propulsion unit, the engineers at Ad Astra have publicly stated that by the early 2020’s they can have a constant acceleration propulsion system (VASIMR) that, suitably scaled up, will get a mission-viable mass to Mars in 39 days. I spoke to them about a 1-g propulsion unit and they said it’s possible but not anytime soon. A 1-g propulsion unit is probably 25 years away — maybe more — if we make a firm commitment of resources and money now.
Yes, fuel will be a large part of the mass of such a unit as it is in any propulsion system but an appropriate design of the magnets generating the confinement field should increase efficiency and keep the fuel mass well within operational parameters. I can’t make an estimate as to the amount of fuel needed but certainly a feasibility study could outline a rough design and fuel requirements.
It won’t be easy or cheap but it’s possible and such a propulsion system will open up the solar system to manned and unmanned exploration. The technology already exists as a test bed at Ad Astra and NASA plans to put an operational unit on ISS to help it maintain orbital altitude. That’s a human-rated propulsion system they’re strapping to ISS. That’s a high level of confidence in the technology.
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 reasonable 1G effect without out the astronauts getting nauseous from the rapidly spinning wheel. See: http://www.uh.edu/engines/epi2638.htm
Also, I could not find anything that says artificial gravity doesn’t work. If you drop a ball in artificial gravity using centripetal force, it would bounce. If you could show me something that says NASA gave up on artificial gravity because it doesn’t work, that would be appreciated.
And yes you do have mass in space. What you don’t have is weight.
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 the Earth, for all intents and purposes, has remained virtually unchanged. Every living thing since the first cyanobacteria winked into existence has dealt with and evolved in concert with an unchanging gravitational field. Every living thing, past and present, has this one environmental factor in common.
Humans evolved into bipedal locomotion and, correctly or not, it is seen as one of the contributors of our ascent to sapience. Walking on two legs is certainly not unique so its contribution to cognizance is debatable, but all locomotion requires musculature and energy reserves sufficient to overcome gravitational attraction. And, with that attraction always present and reliable, we evolved to work with it just as so many other creatures have. Unlike four-legged locomotion, however, bipedalism requires, at some point, a minimizing of gravity’s attraction (that slight bounce in our walk that typifies us in motion) to facilitate moving the trailing leg forward. We can’t, like our four-legged cousins, leave one leg firmly planted on the ground as we reorient the other three.
As I noted in a previous reply, walking has been described as a controlled fall. We lean forward in the direction we wish to go and if we do nothing else we fall flat on our face. If we wish to traverse a distance, however, we bring a foot forward about 2 feet and transition our torsos, superbly balanced atop the forward leg, rotating it over the leg and foot. Part of this motion of our torsos over the leg also imparts a slight thrust upwards. Our muscles and evolutionary design allow us to momentarily exceed the pull of gravity allowing us to raise our bodies just enough to bring our trailing foot forward and prevent us, once again, from falling on our face. We do this over and over again effortlessly and without any thought … and we’ll do it the same way in a spinning space ship.
As noted earlier, the angular momentum of the spinning ship imparts the illusion of 1-g. As long as you stay in one spot the constantly changing angle of your body inside of the wheel will impart the illusion of gravity as your body is constantly prevented from flying off in a straight line. But, as also noted before, the illusion of 1-g is just as easily neutralized by an attempt to walk normally and, since there’s no Earth-equivalent mass to pull you down, once the only source of your illusion of 1-g is neutralized there’s no way to regain it except to place your feet on the floor which you’ll have a lot of trouble doing because you’re bouncing around inside the vehicle.
Perhaps if everyone wore the iconic magnetic boots so one foot was always in contact with the floor there might be a place for this idea. But you’ve still got a massive vehicle to build, balance and fly for 6 months or more with all of the issues of the long flight time unaddressed.
So, inductively, I concluded (yep, I did this on my own with nothing empirical to point to … no one has any evidence for any conclusions they draw about spinning including those in favor of spinning a spaceship) that without the mass of the Earth to work in concert with, and understanding that each human step momentarily and ever-so-slightly breaks the pull of gravity, an astronaut in a spinning spaceship would get seriously injured from bouncing around inside if he/she attempted to walk normally.
Going back to Einstein’s Equivalence Principle of 1907, accelerative gravity is indistinguishable from inertial gravity (what we have here on Earth) to the body that is affected. This is why, I believe, the only solution to the myriad problems of a 6 month transit to Mars, is to develop a constant, 1-g propulsion unit that all but eliminates the transit time issues and provides the gravity equivalent we absolutely require for good health and function. As I’ve noted, it won’t be easy, it won’t be cheap and there’s a lot of engineering that needs to be considered. But, while everyone was saying it was impossible, we developed the technology and went to the Moon . We can do this.
So there it is. I’m speculating but I think it’s from a reasoned and considered base of understanding of human physiology and what little I know experientially of zero-g. My beef with the spinners is that none of them looks at the entire problem, just the parts that seem to support their desire to wish that sci-fi is science.
Sci-fi is entertainment, that’s all. No matter how much science fiction seems real and no matter how many speculative stories of sci-fi have been brought to scientific reality, there’s an awful lot of sci-fi that is nonsense and will go nowhere in the real world of physics. It behooves all of us to remember that when we are dazzled by sci-fi spectacle.
Sci-fi is nothing more than money-making entertainment. Science is a description of the physical world that we actually live in. NASA is working long and hard within the unforgiving limits of physics and engineering to create machines, processes and missions that will truly amaze us and benefit us. One of NASA’s enduring problems, though, is sci-fi. It is enormously insulting to them to have sci-fi kiddies demanding sci-fi solutions to the enormous engineering challenges that they are dealing with.
You comments, please.
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.