ISS Artificial Gravity Study Shows Promise For Long Duration Spaceflight

The International Space Station is humanity’s most expensive gym membership.

Since the earliest days of human spaceflight, it’s been understood that longer trips away from Earth’s gravity can have a detrimental effect on an astronaut’s body. Floating weightless invariably leads to significantly reduced muscle mass in the same way that a patient’s muscles can atrophy if they spend too much time laying in bed. With no gravity to constantly fight against, an astronauts legs, back, and neck muscles will weaken from disuse in as little as a week. While this may not pose an immediate problem during spaceflight, astronauts landing back on Earth in this physically diminished state are at a higher risk of injury.

Luckily this problem can be largely mitigated with rigorous exercise, and any orbiting vessel spacious enough to hold human occupants for weeks or months will by necessity have enough internal volume to outfit it with basic exercise equipment such as a treadmill or a resistance machine. In practice, every space station since the Soviet Union’s Salyut 1 in 1971 has featured some way for its occupants to workout while in orbit. It’s no replacement for being on Earth, as astronauts still return home weaker than when they left, but it’s proven to be the most practical approach to combating the debilitating aspects of long duration spaceflight.

Early NASA concept for creating artificial gravity.

Of course, there’s an obvious problem with this: every hour spent exercising in space is an hour that could be better spent doing research or performing maintenance on the spacecraft. Given the incredible cost of not just putting a human into orbit, but keeping them there long-term, time is very literally money. Which brings us back to my original point: astronauts spending two or more hours each day on the International Space Station’s various pieces of exercise equipment just to stave off muscle loss make it the world’s most expensive gym membership.

The ideal solution, it’s been argued, is to design future spacecraft with the ability to impart some degree of artificial gravity on its passengers through centripetal force. The technique is simple enough: just rotate the craft along its axis and the crew will “stick” to the inside of the hull. Unfortunately, simulating Earth-like gravity in this way would require the vessel to either be far larger than anything humanity has ever launched into space, or rotate at a dangerously high speed. That’s a lot of risk to take on for what’s ultimately just a theory.

But a recent paper from the University of Tsukuba in Japan may represent the first real steps towards the development of practical artificial gravity systems aboard crewed spacecraft. While their study focused on mice rather than humans, the results should go a long way to codifying what until now was largely the stuff of science fiction.

An Imperfect Comparison

Perhaps the most interesting element of “Transcriptome analysis of gravitational effects on mouse skeletal muscles under microgravity and artificial 1 g onboard environment” is that the researchers didn’t originally set out to study artificial gravity, per se. The goal was to simply learn more about muscular atrophy in mammals at the molecular level as it pertains to long duration spaceflight. Traditionally, this sort of research has been done by sending one group of mice to space for a week or two and then comparing their muscle tissue to a group of control mice that stayed on Earth. But the team realized early on that such an experiment was fundamentally flawed.

The Shuttle’s AEM gave mice a place to stay, but no gravity.

When there’s a control group and an experimental group, the idea is to have both groups exposed to the exact same conditions except for the one you wish to study. In that way, you can be reasonably sure that any changes you observe were caused by that one missing element. But with the classic approach to studying rodents in space, this simply isn’t possible.

Consider for a moment the journey our experimental mice face. To start with, they’ll be shot into orbit on a rocket. Not exactly an everyday occurrence for a mouse. While in space they’ll be living in an environmental microcosm artificially maintained by the spacecraft’s life support systems, and even with shielding, will be exposed to a certain degree of cosmic radiation. At the end of their stay they get packed back into a returning spacecraft and sent hurtling through the atmosphere, only to end their ordeal by getting dunked into the ocean. Meanwhile, the control group has just been sitting in a cage in some laboratory the whole time.

These are hardly comparable experiences. Some of these elements could certainly be simulated on Earth for the control group, but not with the degree of accuracy that would be necessary to completely cancel them out. There are simply too many variables at play to exclude the possibility that they’ve impacted the results of the experiment. What the researchers realized they needed was some way to have the control group experience all the same aspects of spaceflight as the experimental group, with the exception of spending time in microgravity.

Leveling the Field

Their answer was the Multiple Artificial-gravity Research System (MARS). By utilizing a small centrifuge, the Mouse Habitat Unit (MHU) aboard the International Space Station is able to spin up half of the mice to a speed fast enough to approximate Earth gravity. The rest of the mice live in the bottom of the unit, which is otherwise identical except for the fact that it doesn’t rotate. In this way the researchers could be sure that all of the mice in the unit were exposed to the same environmental conditions, minus the presence of gravity.

Even still, the paper explains the comparison isn’t perfect. The control group still spends some time in microgravity, as there’s no provision for providing artificial gravity while they are traveling to and from the ISS on the SpaceX Dragon. There’s also a certain amount of processing time before the mice can be removed from the Dragon and moved to the MHU when they first arrive.

That said, both the control and experimental groups go through the same process. So while the control group is exposed to a few relatively brief periods of microgravity that they wouldn’t have gone through on Earth, it’s still an environmental condition that’s shared with the experimental group.

The results of the experiment, which was actually conducted back in 2016, fall exactly in line with what scientists have believed for decades: the mice kept under artificial gravity during their stay on the ISS did not experience the same muscle loss as those in microgravity. Further, the muscleโ€™s gene expression was found to be different between the mice in the control and experimental groups. This strongly suggests that it was the absence of gravity that caused the change, and not space radiation as was previously theorized.

There was little question that generating artificial gravity aboard the ISS was possible, and the fact that it prevented the degenerative muscle loss experienced in weightless conditions was similarly predictable. However, this experiment provided the concrete evidence demanded by the scientific method. More experiments will of course be necessary to further expand our knowledge in this field, but for the time being, it’s safe to say that spinning a spacecraft will indeed prevent mammalian muscle loss during long trips in space.

Exploring New Frontiers

While scientists can use a centrifuge to study the effects of gravity beyond 1 g here on the Earth, there’s no way to reduce the influence of gravity in the lab. But since the ISS is already experiencing weightlessness by virtue of its location in orbit, a centrifuge can be used to produce artificial gravity between 0 and 1 g. This puts MARS in a very unique position as it could allow researchers to simulate the gravity on the Moon or Mars, giving us a glimpse at how long-duration stays on those bodies would impact human physiology.

This is critical information to have if humanity is ever to establish a permanent outpost on the Moon or conduct crewed missions to Mars. The only knowledge we have about human adaptability to lunar gravity comes from the relatively brief surface stays during the Apollo program, and we have almost no idea how the human body would respond to months or perhaps even years on the Martian surface.

The research could also have an impact on future space stations. What if you only need to simulate some fraction of Earth’s gravity to keep muscle atrophy at bay? Determining the minimum amount of gravitational force necessary to slow or even halt the damaging effects of long duration spaceflight could make producing artificial gravity much easier than is currently assumed.

At the close of the paper, the researchers hint that this is precisely the sort of experimentation they hope to conduct in the future:

Although the current study was made possible by state-of-the-art devices that implement an artificial 1 g onboard environment in the ISS, future studies of mammals will validate the effect of long-term habitation under gravitational forces weaker than 1 g, which is meant to simulate the gravity of the Moon and Mars, known as partial gravity. As experiment methods for space biology continue to develop, future studies may more conclusively identify the underlying causes and offer strategies to prevent muscle atrophy.

105 thoughts on “ISS Artificial Gravity Study Shows Promise For Long Duration Spaceflight

  1. A really neat follow-on to rotating a habitat on the way to (say) Mars: if you make it big enough you can make your rotational speed high enough to cancel much of your re-entry speed: just cut the tether at the right time and fall at relatively low speed from a low periapsis (periareion), potentially eliminating an entry heat shield entirely. Exercise for the reader: how long a tether do you need to spin something at 1g, but fast enough to reach Mars re-entry speeds (say 5 km/s)?

    Now, if you’ve got the unobtainium tether strong enough and long enough to do that, the next level is almost trivial: do it in reverse, and pick something up off the surface with that tether, eliminating the need for a booster rocket too. (Not a new idea: Sir Clarke described it in SODE,/i>, and it existed long before that).

          1. I didn’t know Wolfram could do that.

            I just used my trusty TI-92 calculator with its units and zeros function.

            I don’t like relying on web services for my math, and I don’t feel like installing Mathematica (not even sure if my employer has a license for it).

          1. Depends on its thickness, right?
            But rope that long made of any material we can currently make can’t even support its own weight.
            Hence, unobtanium.

          2. What [Paul] said:
            I read (long ago) that there is no known material (including spider web) that can hold the weight of 100 miles (161 Km) of its own length. IOW, a distance that is a lot shorter than Alaska.

            So, that kinda rules out space elevators for the time being.

      1. Indeed. Less power requirements, however, it needs to be positioned a fair way away from the object it’s projecting. Not to mention the recovering effect behind it. Think fluid dynamics with plasma. AA staggered Fresnel lens like setup might be a better compromise.

      1. Or 2001 A Space Oddysey, which I specifically bought on Blu-ray, which was almost as good as seeing it in the cinema when it first came out (at the age of 5, my dad was a bit perplexed at my choice of birthday outing….).

        1. Considering that movie,
          I have never figured out how they made artificial gravity in the Pod Bay.
          And exterior shots of Discovery, don’t give a clue about where the rotating habitat is located.
          At least the Russian craft in 2010 had a rotating portion (even if it did make noise in the exterior shots).

          1. In the book, Clarke made a point that repair work should be done in gravity (the spun portion) to avoid molten blobs of solder floating around. But the pod bay is cleary not in the spun section. They do walk around on sticky boots in there though, so implies it’s zero g.

            But, yeah, the internal map of that ship doesn’t seem to match the exterior size: the tunnels that access the pod bay go off at an angle that should exit the ship hull. Maybe Kubrick borrowed a Tardis from the Pinewood back lot, or perhaps Heinlein’s Gay Deceiver internal topology.

            But it seems obvious the axis of rotation of the wheel is along the long axis of the ship: it’s the only place the wheel would not intersect other obvious exterior features (windows, pod bay, ship spine). Also, if under thrust, that would give uniform (sideways) force to things on the wheel.

            What bothered me very greatly about that was in 2010 when they found the derelict Discovery (with the wheel spun down and transferred its angular momentum to the ship), it was spinning around the wrong axis! I actually said so out loud in the theater. (Right before my future wife kicked me :-/ ) I suppose it could have precessed over that time into that more stable spin axis, but still, it was wrong!

      2. That movie is touted as being good hard science fiction but it has issues, e.g. the scene where she removes the door and it spins away then hits something, where did the sparks come from if there is no oxygen in space to cause the small bits of metal to become pyrophoric?

  2. The Naval Aerospace Medical Research Laboratory in Pensacola FL has a unique and quite large centrifuge that’s well suited to artificial gravity research. In particular, they’ve looked at the effects of living in a rotating frame of reference for extended periods (weeks!). (I didn’t ask how they handled moving fluids in and out of the rotating room for that length of time. I’m guessing it involved buckets…) They found (among other things) that you can adapt and work effectively in a rotating frame even as fast as 10 rpm. It’s fascinating stuff.

    1. There are rotational couplings designed to handle several fluids and gasses in both directions along with electricity. They tend to be specialized and one-off builds.

    2. It is very interesting.
      I really do hope to see a space vessel of some kind testing a human scale centrifuge. Maybe we can ask Elon to send up a couple of Dragon capsules and tether them together.

      1. All motion is relative. If you’re spinning at the same rate and direction as the thing you’re looking at, you can correctly say that everything else is rotating and you and the thing you’re looking at are not.

        1. I think if you were to hold a stationary bucket of water above a rotating one so that they have a common axis of symmetry, you would be able to tell which one is rotating no matter your frame of reference. The rotating one is also an accelerating frame, and only non-accelerating frames are equivalent. “All motion is relative” isn’t the same as “all inertial frames are equivalent”.

  3. I wonder if having artificial gravity just in the sleeping unit would provide equivalent or better protection than the current workout regimes. Would probably be more practical than providing artificial gravity for the whole ship.

    1. That’s what I was thinking since the article says that the lack of gravity caused a change in gene expression, maybe just sleep gravity would be enough to reduce muscle wasting. What we have to find out is what is the minimum time/g exposure needed to keep muscle wasting in check. Maybe with a does of anabolic steroids we could keep astronauts in relatively good shape in zero g.

  4. There are problems with using centripetal force to simulate gravity. First, if the rotating structure is not large enough (research suggests 250 ft in diameter) you end up with dizzy astronauts. Look up The Graviton or The Rotor carnival ride. The second problem is mass distribution. If the mass in the rotating structure in space is not evenly distributed the whole structure will wobble or precess like an out of balance childs top. So when they put a rotating hotel in space your room will be on one side of the wheel and your MIL with all her luggage will be on the far side (just kidding about the MIL).

    1. Garth- excellent point. This is a concern I have rarely seen addressed. I would think any zero-g centrifuge would need a system of weights or fluids that would automatically reposition around the perimeter of the ring to compensate as people move around inside, so as to keep the center of rotation the same. In addition, it would need a system of interlocking slip couplings at the center to compensate for changes in the center of rotation. It would also need propulsion to keep the centrifuge spinning, as friction from various sources would cause it to slow down over time. Not to mention all the slip couplings needed to allow utilities (power, fluids, waste, etc.) to move back and forth from a rotating mass connected to a stationary one.

      1. Put tube around the circumference with a bunch of steel balls in it, with a light oil for lube and damping. High speed optical drives have that on the motor. The size of the tube and balls, how many balls, and the oil viscosity would have to be just right for a space station.

        1. The oil would have to be in a sealed hub otherwise it would “boil” away like water in a vacuum. Also the oil would have to tolerate extreme swings in temperature from boiling hot to hundreds below zero. If I recall the ISS uses a silicone grease in the gear mechanism for the solar arrays. Don’t think your earthbound analogy would work in space.

          1. Nope, not silicone. It’s a very low vapor pressure fluorocarbon grease with suspended Teflon particles.
            FWIW the Canadarm uses solid lubricant (molybdenum disulfide).

        2. Works for lots of other applications too. I once had to change a bunch of tires out in the middle of nowhere, with no facilities for balancing. Tires are easy enough to change with tire levers, but without balancing they will shake like crazy. A couple ounces of birdshot salvaged from shotgun shells did the trick: it distributed itself around the tire wherever it was lighter, and equalized the weight. Starting up was a bit rough, but once all the tires balanced themselves, they’d stay that way till you stopped. I was going to get them balanced as soon as I was back in civilization, but never bothered since it worked so well. Lasted the life of the tire too.

          I got the idea from an old trucker, who said they used to use mercury.

  5. Lots of interesting ideas to think about for a rotating hab.

    1) If you run with the spin, you would increase “gravity” but if you ran against the spin, you would decrease “G”. In fact, if you ran fast enuf, you would start floating, making large leaps across the floor until you ran in to something.

    2) Your head would be a different G than your feet, and depending on the radius of the hab, it could be substantial, Wonder how the body would adapt to that.

    3) The seals and bearings for the rotating hab would haf to be able to adapt to differences in the instantaneous center of gravity as people and things moved about the hab. (Mentioned above)

    4) Lastly, it would be a dangerous surface to work on _outside_ the station, where you might get flung off into space, and if you were on a tether, you would be subjected to many Gs out at the end of your rope.

    1. 4) That’d have to be a tether free job. Flying off wouldn’t be so bad. Just send someone to pick them up. Hitting the end of the tether would be terrible. Better yet, stop the spinning for maintenance.

  6. Another idea is to just have a stationary trend, with a diameter of 10 m and run in side it to get the desired G. By my calculations (some one check!) if you ran around that 10 times per minute, you would be a 0.56 G. That would be about a 6 or 7 min/km which should be an easy jog for an astronaut.

    1. 10 times per minute around a 10 m diameter (31.4 m circumference) hoop is 314 m/min, 3.1 minutes/km. Pretty quick.
      0.56 g is right though.

      Another Clarke book (Imperial Earth, I think) uses a bicycle racetrack like that around the ship to train for higher g on the trip to Earth, for visitors from lower-g worlds (Titan in this case).

  7. That moment, when you’re literally writing about centrifuges used to simulate gravity on mice and still call it the “centripetal force”. Why do people always mistake those two?

        1. I’ll take that as a big “No” then.

          Accepting when you’ve made a mistake and learning from it is a critical part of growing as an individual. The only person you hurt with this mentality is yourself.

          1. Dude, just think about it.

            It’s called a centriFUGE, not centriPETE. Rotating things generally tends to force them outwards.
            Think on how a centrifuge works in the context of separating white/red blood cells. Think about why it separates in the first place and how a centrifuge accelerates this process.

            (also, posting wikipedia links to make your point is utterly pointless, since basically everyone and their nan can edit those articles.)

            You too can learn things.

          2. BTW, the funny part is what the article linked by you says: Thus, the “gravity” force felt by an object is the centrifugal force perceived in the rotating frame of reference as pointing “downwards” towards the hull.

            That’s next level of denseness.

        2. You’re so close to figuring this out, let me help you over the finish line.

          The astronaut experiences centrifugal force, but the station/spacecraft is imparting centripetal force. They are both two sides of the same principle, it’s just a matter of perspective. So if you are talking about the spacecraft that’s rotating, the correct term is centripetal. If you are instead focused on what is happening to the individual, then you would sub in centrifugal.

          You aren’t wrong using your example, but that’s not how the term is used in the article.

          1. You fail to realize that you’re on the wrong side of the finish line.

            “The ideal solution, itโ€™s been argued, is to design future spacecraft with the ability to impart some degree of artificial gravity on its passengers through centripetal force. The technique is simple enough: just rotate the craft along its axis and the crew will โ€œstickโ€ to the inside of the hull.”

            That’s the exact passage and the term used is the wrong one. The important bit is “Impart artificial gravity on its passengers”, hence it is indeed focused on what is happening to the individual.

            Yes, I know that both forces are present in a rotating system because otherwise it wouldn’t be rotating but just flinging stuff through space. But the article is talking about creating artificial gravity for the humans inside said rotating system. This automatically implies the force pulling away from the center of rotation. Therefore: Centrifugal.

            Technically, centripetal force doesn’t even require any form of rotation. It’s just the force keeping you from going away from the center of rotation. In most demonstrations it’s a rope, one end attached to a rock and the other held in a hand. In this case it’s the hull of the ship. Hell, it could be a jet engine pushing you inwards in a larger rotating system.

          2. All of you are so close, just let me push you further over the line….

            Centripetal force and centrifugal force are pretty much the same thing. Which one you use depends on your frame of reference.

            Is your frame of reference rotating with the spacecraft (use centrifugal) or stationery, watching the thing rotate from the outside (use centripetal).

          3. @abjq: Sadly not, they are not the same, it’s just a conclusion which pushes itself into peoples heads since they are observing or referencing to – for the lack of a better word – “closed-loop” rotating systems, where one system is providing both forces. The spinning space station is the perfect example of that, the station rotates and exerts a centrifugal force upon the astronaut, pushing them onto the stations hull which in turn produces a centripetal force which keeps them from flying out into space. There are two forces acting upon the astronaut in opposite directions, but since they are provided by the same system, most people tend to see them as the same thing.

            But this conclusion falls into pieces when you start referencing to non-traditional cases where both forces are present but not caused by the same thing. And of course if you remember that two counteracting forces can not be the same. The easiest one would be an ice skater taking a turn. His motion along a curved trajectory automatically implies that there is a force trying to push him out on a wider curve. This force is centrifugal, “centrum” for “center” and “fugere” for “fleeing” or “escaping”.
            But why does he not go onto a wider trajectory? His skates exert a counteracting force by friction against the ice surface. This force is the centripetal force, latin “petere” for “seeking”.

            Also see further examples like cars or motorcycles, especially on banked turns. Or a ball in a roulette wheel.

            Additionally, a very non-traditional example would be humans just standing on Earth itself. Since the planet is spinning, there must be a centrifugal force acting upon us humans. But the counteracting centripetal force – aka gravity – is a lot higher, keeping us from flying off into space. Funny enough, the gravitational acceleration on earth has a .5% difference between the poles, 9,832 m/sยฒ, and the equator, 9,780 m/sยฒ.

    1. It’s because they’re both about spinning and they’re nearly the same word. If my understanding is correct, the one also turns into the other after passing the plane of rotation. Major failure on the part of whoever made those two names up. Similarly, microgravity, partial gravity, etc are all misnomers based on antiquated understandings of what gravity is. Those need to be renamed ASAP. How embarrassing for scientists and the English language.

  8. If this didn’t work it would be the first experiment ever to break the equivalence principle and prove General Relativity to be wrong. Was there someone who that that inertial mass and gravitational mass can be distinguished by living tissue?

  9. Why do people post commentless links to mystery files? Does anyone click on these things? How did this not get hit with a moderation hold while my movie review sits in limbo with no links in the text?

  10. How about a fitted suit that is warn as underware that causes a measured resistance to body movement. Iโ€™m thinking a spandex material. Every time the wearer moves the material would resist causing an artificial gravity.

    1. For something to have resistance it must have one either something else it is pushing against, or inertia. A body suit can only provide pressure, because it is only connected to itself or the human body. Also resistance isn’t a complete analog to gravity. Gravity puts weight, on every centimeter of your body at the same time constantly. All a body suit could do is again give pressure by squeezing or relaxing. Astronauts already where this kinds of body suits when the go on space walks to basically “pressurize” their bodies. This does not solve the gravity problem.

  11. I’m curious whether artificial gravity is a greater evil than spending 2 or 3 hours a day exercising in low / zero gravity. Let’s say an astronaut is aboard a cube-shaped station, and he or she is awake for 16 hours a day where 3 hours is spent exercising.

    Option A (Status Quo): Assuming the workout has 0% relevance to an experiment (which I find hard to accept), this is a productivity loss of just under 19%.

    Option B (Artificial Gravity): In the absence of some force resembling gravity, there is no obvious up or down. I find this interesting because you get the opportunity to treat all inner surfaces as a workspace, so the station has 6 potential work areas. If you added gravity, then you reduce this to 1 potential work area. This is a productivity loss of just over 83%.

    This is clearly an oversimplification, but my initial gut check it is better to waste less than 20% of your time than it is to waste more than 80% of your real estate in the scenario of the ISS. If there was a way to get exercising done during sleep, that would further reduce the value of artificial gravity & could potentially be repurposed for the obesity problem we have down here on Earth.

    1. Exercise was found only to reduce the effects but over long term the bone loss, heart swelling, muscle degradation and other physiological changes still occur.

  12. Instead of spinning the entire spacecraft to create artificial gravity, why not just spin individual humans while they sleep. That might be enough to eliminate or reduce the amount of exercise required.

      1. Really? I envision a capsule located inside the spacecraft in which an astronaut is spun to induce a gravitational pull that mimics nature. It might have to include a “double” spin to average the normal gravitational load experienced on earth. Spinning the entire spacecraft to create a gravitational atomsphere for all astronauts would be folly.

    1. Except in movies, where you throw a switch. But yes, these are ‘g’ forces just like in a centrifuge or airplane or car. Mainly from some mechanical means of keeping you from going straight as nature intended.

  13. Itโ€™s surprising that after 20 years of experiments we havenโ€™t done a lot more to understand this seemingly very basic next step in the process of determining how we should proceed on this grand adventure out into the High Frontier.

  14. “…far larger than anything humanity has ever launched into space.”
    I really dislike this line of thinking. That the only way to have something in space is to launch it, whole, into space. As the ISS confirms, launching small payloads to build a bigger system is the way to go. For any real exploration or habitation, ships and stations are gonna need to grow up. Anything of any size can be built in space without the constrictions of gravity. With as much material as has been launched already and is floating around in orbit, we could’ve already built a massive construction facility and be well on the way to building ships capable of mining asteroids for more material. Such potential and yet such a waste.

  15. Why just now?

    The Russians launched their first space station in 1971. The US managed a little time aboard SkyLab in 1973.
    Wasn’t the point of space stations supposed to be preparation for humans living in space?
    Wouldn’t this be one of the most obvious first things to try?

    Ok, so there were grander plans that fell through involving a module that would spin the astronauts themselves. But really, how hard is it to put some mouse cages in a barrel, connect said barrel to a motor and spin it. I mean sure, look at the thing they finally launched. Like everything in space it is very well built and probably spins accurately to some ridiculously precise fraction of an rpm. I’m sure it’s complicated and expensive and will provide the best data money can buy. But come on, we are almost 50 years into it now. A kid in a garage could have built a mouse centrifuge that might not have been so laboratory grade accurate but would have provided far better than data than no data.

    And it’s news now, when they have only tested 0G and 1G? We have 50 years evidence that 0G is bad for you and about 4.5 Billion years of evidence that Earth life likes 1G. We know the moon has about 1/6G but we only have tried it for a few days at a time. And we have no experience with living in Mars’s ~3/8G.

    Yes, I understand the need for control groups. But this all should have happened a long time ago. And I only see here that they are talking about trying fractional Gs, not definite plans about when. It would be nice if our voters would pay for a spinning module to test on humans but come on! At least hurry up and spin those mice. We should know what different fractions of a G do to mammals by now. It seems to me like it’s already 50 years late!

    1. very good points and some of what i tried to convey. just imagine the Babylon 5 space station. completely fictional and yet a bunch of internet/scifi sleuths have already figured out the appropriate rate of spin for 1G for that size of station. science has become tedious and tiresome to the general populace and in turn the ambition of science has become just as tedious

Leave a Reply

Please be kind and respectful to help make the comments section excellent. (Comment Policy)

This site uses Akismet to reduce spam. Learn how your comment data is processed.