NASA Seeks Public's Help Designing Ways for Astronauts to Live off the Land on Mars

As part of its research and development efforts on in-situ resource utilisation, NASA has recently announced the In-Situ Materials Challenge which seeks proposals from the public on converting in-situ extraterrestrial materials into structural elements that would be useful for human deep space missions. Image Credit: NASA

As part of its research and development efforts on in-situ resource utilisation, NASA has recently announced the In-Situ Materials Challenge which seeks proposals from the public on converting in-situ extraterrestrial materials into structural elements that would be useful for human deep space missions. Image Credit: NASA

In the much-advertised Hollywood sci-fi blockbuster movie ‘The Martian’ which is already taking viewers by storm one week after its theatrical release, a stranded NASA astronaut on Mars struggles to survive alone on the Red Planet while using local resources to stay alive. This fictional portrayal of in-situ resource utilisation on another planet is in the realm of possibility for the future in real life, and NASA is actively working on ways to turn this highly promising concept from vision to reality.

To that end, the US space agency has recently issued a request for proposals for its In-Situ Materials Challenge, inviting the public to submit designs for systems that could construct structural elements from materials that are native on the Moon, Mars and other extraterrestrial destinations.

The Red Planet. Photo Credit: NASA/JPL

The Red Planet. Photo Credit: NASA/JPL

The prospect of incorporating in-situ resource utilisation, or ISRU, as a critical part of a crewed space mission to other extraterrestrial destinations, has been a topic of much research even before the first humans ever set foot upon the Moon during the Apollo 11 mission in 1969. Even though it has never advanced beyond the conceptual stage, in-situ resource utilisation is considered as a game-changer for human missions beyond low-Earth orbit and rightly so. Contrary to taking all of their required supplies and material with them from Earth, astronauts on deep space missions could learn how to use local extraterrestrial resources instead for the creation of food, water oxygen and fuel, as well as for the construction of habitats, shielding equipment and other structures on other planetary surfaces.

Given that the current cost of launching 1 kg into low-Earth orbit is in the order of $10,000, the process of converting raw extraterrestrial resources into useful material and equipment for human deep space missions could be the key for turning the latter from financially unaffordable to affordable ones. With that in mind, NASA has already researched the concept of ISRU extensively, while several such analog field tests that the agency had conducted in the late 2000’s had returned promising results by demonstrating the successful processing and production of water, oxygen and other resources from simulated lunar regolith.

The space agency’s latest initiative on ISRU research was announced earlier this week on Oct. 7, at an event honoring the five years of operations of the Challenge.gov technical platform, which seeks to engage the public on finding solutions to scientific and technical problems through challenge and prize competitions. One of the platform’s newest listings, the In-Situ Materials Challenge is run by the Ohio-based NineSigma Inc. as part of NASA’s Tournament Lab which fosters competition among academia and industry for various research and development efforts. The goal of the In-Situ Materials Challenge is to select the best hardware design submitted from the public, for converting in-situ extraterrestrial materials into structural elements that would be useful for human space missions on the Moon and elsewhere. To that end, all interesting parties can apply and submit their entries at the NineSights community website, by December 3, 2015 on 5 PM EDT.

The Challenge’s incentives are a $10,000 prize for the first-place winner and two $2,500 prizes for second place. In order for design submissions to be eligible, they must “demonstrate and/or provide analysis that shows a method for converting granular regolith or basalt into a useful product to support manufacture of structural elements”, according to the Challenge’s rules, while the demonstrated technology must also be easy to operate and compact enough so that it can fit within certain payload package constrains. “NASA’s newest challenge is yet another stellar example of the agency’s commitment to harnessing the ingenuity of citizens as we seek to expand the frontiers of knowledge, capability and opportunity in space,” said Dr.Ellen Stofan, NASA’s Chief Scientist, during the Challenge’s announcement on Oct. 7. “Exploring Mars and other worlds is a herculean endeavor. Like other agencies across the federal government, NASA recognizes that our success will be enhanced greatly by involving people with all kinds of knowledge, skill sets and ideas in our work,”

The selected winners for the In-Situ Materials Challenge will be announced in late January 2016, while the successful applicants will have the opportunity for a future collaboration with NASA as well. “In situ resource utilization is key to our exploration of the Universe,” says Robert Mueller, a senior technologist at Swamp Works, an engineering and development lab at NASA’s Kennedy Space Center in Florida. “We must find ways to make what we need once we are at our destination. For example, the soil on Mars could be used to make modular structural building blocks to make shelters, landing pads and other useful structures. We are looking for creative and novel solutions from all types of people”.

NASA's Curiosity Mars rover on the surface of Mars. Photo Credit: NASA/JPL-Caltech/

NASA’s Curiosity Mars rover on the surface of Mars. Photo Credit: NASA/JPL-Caltech/

If human missions on deep space destinations are to become affordable both technically and financially in the future, in-situ resource utilisation will have to play an increasingly larger role in their design. The rapid development of additive manufacturing, also known as 3-D printing, could potentially be part of such ISRU technologies as well. Last year, astronauts on the International Space Station successfully demonstrated the construction of materials in microgravity through additive manufacturing, as part of NASA’s 3D Printing in Zero-G Technology Demonstration. While previously placed firmly in the realm of science fiction, it’s not now inconceivable to imagine additive manufacturing technologies as an integral part of in-situ resource utilisation on future deep space missions to the Moon and Mars. “The utilization of native materials is a boon to construction whether Earth-based or extraterrestrial”, commented NineSigma Inc. in a press release on the announcement of NASA’s In-Situ Materials Challenge.

“The benefits are dramatic for space exploration because in-situ regolith utilization (ISRU) will reduce the need for materials to be shipped from Earth, which creates additional useful payload mass for habitats, structural systems, life support systems, science equipment, and living provisions. ISRU could potentially save the agency more than $100,000 per kilogram at launch, making space pioneering more affordable and feasible.”

In the same spirit of the Lewis and Clark Expedition which during the early 19th century traversed the then-uncharted lands of the western United States and learned to “live off the land”, the first human explorers of uncharted extraterrestrial lands during the 21st century will most probably follow in the footsteps of their ancestors and will learn to make the most of what their otherworldly locales will offer them.

 

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28 comments to NASA Seeks Public’s Help Designing Ways for Astronauts to Live off the Land on Mars

  • Colorado

    The first “In Situ” resource all space enthusiasts should be enthusiastic about is the possibility of these immense ready-made radiation sanctuaries on the Moon.

    http://www.purdue.edu/newsroom/releases/2015/Q1/theoretical-study-suggests-huge-lava-tubes-could-exist-on-moon.html

    • James

      Yep.

      High-energy Galactic Cosmic Rays are nasty and several or many meters of already formed Lunar ISRU shielding is useful protection. The “ready-made radiation sanctuaries” should be great assets!

      Long-term human missions in space and on the Moon, Mars, and Ceres may also need ‘artificial gravity’ to maintain the good health of the astronauts.

      The article noted, “To that end, the US space agency has recently issued a request for proposals for its In-Situ Materials Challenge, inviting the public to submit designs for systems that could construct structural elements from materials that are native on the Moon, Mars and other extraterrestrial destinations”, so perhaps learning more about building an appropriately sized ‘artificial gravity system’ out of ISRU materials would be useful.

      Research is needed to find an appropriately sized and technologically doable ISRU based ‘artificial gravity system’ with comfortable rotation rates, useful adaptation and mitigation techniques and medicine to avoid centripetal acceleration caused motion sickness if we are serious about having humans use ‘artificial gravity’ for months or years while exploring our Solar System and establishing off Earth colonies.

      The crucial issues for human comfort seem to be having a system with a long radius and one Revolution Per Minute (or RPM), or less, for creating useful centripetal acceleration ‘artificial gravity’ and avoiding dizziness and motion sickness.

      It might be worth considering some approximate numbers in order to get a partial view of the ‘centripetal acceleration artificial gravity’ situation, and maybe those numbers could suggest methods for further experiments here on Earth and a better understanding of the technical and ISRU requirements for building such a system.

      How long would the radius be for 1 “G” of centripetal acceleration while having only 1 Revolution Per Minute, or RPM, so that most folks would not be bothered by repeatedly going around in a circle and could avoid dizziness and motion sickness?

      The answer is that the radius would be about 894 meters or 2,934 feet. The tangential velocity or ‘circling speed’ of the habitat would be about 93 meters per second or 209 miles per hour or 337 kilometers per hour.

      If 2 RPM is an acceptable rotation rate that most space travelers could eventually adapt to, then the radius for 1 “G” of centripetal acceleration would be about 224 meters or 733 feet. The tangential velocity or ‘circling speed’ of the habitat would be about 47 meters per second or 105 miles per hour or 169 kilometers per hour.
      If 1 RPM is used to create .376 “G” of centripetal acceleration to simulate the gravity of Mars, the radius would be about 336 meters or 1,103 feet. The tangential velocity or ‘circling speed’ of the habitat would be about 35 meters per second or 79 miles per hour or 127 kilometers per hour.
      If 2 RPM is used to create .376 “G” of centripetal acceleration to simulate the gravity of Mars, the radius would be about 84 meters or 276 feet. The tangential velocity or ‘circling speed’ would be about 18 meters per second or 39 miles per hour or 63 kilometers per hour.
      If 1 RPM is used to create .165 “G” of centripetal acceleration to simulate the gravity of the Moon, the radius would be about 147 meters or 481 feet. The tangential velocity or ‘circling speed’ would be about 15 meters per second or 34 miles per hour or 55 kilometers per hour.

      If 2 RPM is used to create .165 “G” of centripetal acceleration to simulate the gravity of the Moon, the radius would be about 37 meters or 120 feet. The tangential velocity or ‘circling speed’ would be about 8 meters per second or 17 miles per hour or 28 kilometers per hour.

      If any of these above numbers are wrong, please correct them.

      The crucial issues for human comfort seem to be having a system with a long radius and one RPM, or less, for creating useful centripetal acceleration ‘artificial gravity’ and avoiding dizziness and motion sickness.

      If some university, company, or individual has some flat land and is able to afford laying a banked railroad track in about a 6,000 foot diameter circle, a 3,000 foot diameter circle, a 2,000 foot diameter circle, a 1,000 foot diameter circle, a 500 foot diameter circle, and a 250 foot diameter circle, then perhaps some useful research on more clearly defining some of the RPM and other constraints of very long-term exposure and adaptation of humans to centripetal acceleration while avoiding motion sickness could be accomplished at a reasonable cost with a railroad based moving habitat.

      Such research could help define the many technical parameters of an ‘artificial gravity’ system that could be built with ISRU materials.

      Extensive system testing and onging ‘artificial gravity’ research on Earth is needed to define comfortable rotation rates and other critical design and relevant ISRU technology issues if we are serious about having humans use ‘artificial gravity’ for months or years or decades while exploring and colonizing our Solar System.

      • Colorado

        In 1966 Gemini 11 did a tether-generated artificial gravity experiment. A several thousand foot long tether system with equal masses on either end generating one gravity is the solution that people have been doing calculations for since the 1930’s (it was not known if humans would remain conscious without gravity so the tether was a solution to this possibility even then). No extensive testing is needed. We just need to build it and use it as it is pretty straightforward.

        The ice on the Moon is the source for shielding. 15 feet and several hundreds tons of water for a small capsule. Well over a thousand tons for the very minimal crew space needed on a long duration mission. This is also pretty straightforward as well as how to push such a shield around the solar system- there is only one practical system. All the work to conclusively prove this concept was done in the 60’s and includes over 1000 live tests of the required devices.

        • Colorado

          And as for “living off the land” on Mars, what started the space colonization movement of the 70’s was the singular conclusion that one gravity was a prerequisite to any permanent colony. The less gravity the easier it is to build centrifugal “sleep train” facilities for small crews on small icy moons but for large populations miles in diameter artificial spinning hollow moons constructed of lunar material has always been, and will remain, the best plan.

          It goes without saying (but I will say it anyway) that such a public works mega-project is the anti-thesis of the NewSpace scam (retire on Mars!) presently being endlessly hyped to the public.

          • Colorado

            To generate one gravity on the inner surface of a sphere about 6000 feet in diameter the sphere would spin a little over 200 miles per hour and complete one revolution in a minute or so. A person living in such a sphere would take about an hour to walk the circumference and arrive back at the starting point.

            It is a good example to explain what a Bernal Sphere would be like.

  • Melba Lallab Fernandez

    a lot of creative Chemistry would be vital here…. I do believe that one day Man would find answers here….. I have no doubt about this.

  • James

    Building a Lunar “sleep train” out of ISRU available materials and technology here on Earth would allow extensive testing of such a system for several decades.

    Building an ISRU “sleep train” here on Earth would over time allow large numbers of people to be tested in such an environment.

    Optimal RPM, the diameter for the circle of railroad track, and needed technology for the ISRU “sleep train” are still not clearly defined.

    Human psychological and physical reactions to living for years on such a circling ISRU “sleep train”need to be explored.

    Long-term testing of such an ISRU technology “sleep train”on Earth is both cheaper and far less risky than doing such testing in space or on the Moon.

    Extensive and very long-term research with a Lunar ISRU technology based “sleep train” here on Earth could be quite useful in reducing some of the real and diverse risks of space exploration and colonization.

    • Colorado

      I disagree. It is not necessary. It is two equal masses and some cables spinning in a circle to generate one gravity; there is none of years of testing you are talking about necessary. Are you trying to get a government contract to build the “test track”?

  • James

    Mars and Lunar rovers get tested on Earth. Testing an ISRU technology ‘Artificial Gravity’ “sleeper train” on Earth would be useful.

    Note the article ‘New Artificial Gravity Tests in Space Could Help Astronauts’ by Jeremy Hsu, SPACE.com Senior Writer May 12, 2010, “Then there are also biomedical questions about whether astronauts encounter problems with dizziness or vertigo, and whether the centrifuge is both effective and enjoyable.”

    And the article continues with: “Of course, researchers can begin tackling some of those questions if they can get renewed NASA funding for Earth experiments as well.”

    So do we “begin tackling some of those questions” through “Earth experiments” or do we wait for several more decades for space or Lunar experiments?

    The circular “test track” for the ISRU ‘Artificial Gravity’ “sleeper train” should be built underground in a place with a very cold climate in order to best simulate the actual Lunar, Mars, and Ceres operating conditions. A “test track” tunnel and base in Antarctica might work out pretty good.

    And come to think of it, build at the same “sleeper train” test site a very long and straight buried rocket sled system. The sled would slide along on slippers riding on heavy-duty rails.

    Inherent in testing that cold environment ISRU rocket sled tunnel system would be ‘harvesting’ and recycling the burned propellant, so it might be useful to burn an ‘ALICE’ frozen mixture of aluminum nanoparticles and H2O2/H2O.

    From ‘Holloman High Speed Test Track’ at Wikipedia, “The HHSTT currently holds the world land speed record for rocket sleds set in April 2003, at Mach 8.6, or 9,465 feet per second (2,885 meters per second)”.

    Let’s see, the Moon’s escape velocity is about 2,38O meters per second.

    Mar’s escape velocity is about 5,027 meters per second.

    And the escape velocity for Ceres is about 510 meters per second.

    Lots of useful things might be doable with ISRU technology ALICE rocket sled tunnel systems on the Moon, Mars, and Ceres.

    From ‘New Rocket Fuel Mixes Ice and Metal’ by Jeremy Hsu, SPACE.com October 21, 2009 we find, “But the recent confirmation of water sources on the moon and Mars may hint at a future where ALICE and similar rocket propellants become highly practical.”

    And in the article ‘NASA tests eco-friendly rocket fuel’ by Jeff Salto, August 23, 2009, Dr Steven F. Son from Purdue is quoted as saying, “ALICE can be improved with the addition of oxidizers and become a potential solid rocket propellant on Earth. Theoretically, ALICE can be manufactured in distant places like the moon or Mars, instead of being transported to distant locations at high cost.”

    Let’s build an international base here on Earth in Antarctica to extensively test a useful ISRU based ‘Artificial Gravity’ “sleeper train” and an ALICE ISRU rocket sled tunnel rail system before we try to build and use them on the Moon, Mars, and Ceres.

    • Colorado

      You want to build a “test track” that won’t test anything in Antarctica? No.

      As for ALICE and those other distractions……whatever.

  • James

    Small technical failures can have show stopping consequences.

    See the article today “Smoking Credit Card Reader Forces Plane’s Emergency Landing” ABC News By Erin Dooley and Matt Foster.

    Satellites are tested here on Earth.

    Rocket engines are tested here on Earth. One of the great things about the Space Shuttle Main Engine, or RS-25, is the extensive amount of ‘testing’ it has experienced on Earth and space.

    Those who don’t do extensive testing here on Earth are simply inviting expensive failures in space and on the Moon. Unfortunately, failures in space and on the Moon during human missions can also result in loss of crew situations.

    Those who actually do ‘artificial gravity’ research do most of that research here on Earth. Are they all fools? I doubt it.

    • Colorado

      Can’t do artificial gravity testing when there is natural gravity present. It is pretty obvious that your antarctic test track is not going to happen. Give it a rest James.

    • john hare

      One of the interesting things about Earth side testing is that with one gee already present, a much shorter arm can be used with the same rpms. Instead of a mile diameter 1 rpm, a hundred feet diameter at 1 rpm with slanted track, or 3 rpms in the same diameter with a bit more tilt. Ten mph is a very inexpensive vehicle for testing rpm tolerance. The extra gee will be almost unnoticeable.

      • Colorado

        Ten mph is pretty ridiculous. You guys have fun discussing it.

        • john hare

          The discussion is testing for rpm tolerance and adaptation. As James said, there will be a lot of testing on Earth before risking the building of megastructures in space. That it hasn’t been done yet speaks to the seriousness of efforts to date.

          • Joe

            Such ground based testing was done in the 1960’s. The results of that testing resulted in the current conventional wisdom that 1 or 2 RPM is the maximum allowable to avoid crew disorientation.

            Several years ago (at an Aerospace Human Factors Conference) I had the good fortune to meet and talk to Dr. Joseph Kerwin (medical doctor, Skylab). He told us that based on motion sickness studies performed on Skylab he was convinced that higher RPM rates would be acceptable. This would be significant because the simulated gravity level increases with the square of the RPM’s allowing for significantly smaller structures.

            The problem in ground testing is that the interaction between the rotation and the gravity force may be skewing test results.

            • Colorado

              Attaching empty upper stages end to end at a slight angle results in a torus and the diameter and RPM of the torus determines the amount of artificial gravity. This is of course the classic Ehricke/von Braun wet workshop-into-wheel.

              The design of such a station is problematic because while the rocket stage is built to take mainly vertical loads such a torus would be mainly side loaded. One solution would be to not attach the stages end to end but form the ring by placing them side by side in a row. This has the disadvantage of making each stage a more separate entity and restricts being able to simply walk through a long common corridor.

              A technique that cuts and re-welds the stage material in space into an ideal structure using a automated robot welder might be far simpler than anyone would think. Especially if the stage was designed to be converted. Maybe.

              • Colorado

                I would add that such a 2001-type GEO or BEO wheel would mass in the thousands of tons due to the water shielding required. Once the initial shock and denial wears off this design becomes a pleasing parallel to ships at sea- with a crew necessarily surrounded by a mini-ocean. I greatly dislike space-as-an-ocean analogies but in the case of radiation shielding it fits and is completely appropriate.

                Unfortunately it is just the first shock; how to push that shielding around ramps up the eye-roll factor by an order of magnitude. There is only one practical system now and in the foreseeable future; H-bombs. Again, once the denial stage wears off and it is appreciated just how much bomb material is sitting around this planet- and the above ten thousand Isp numbers that fissionable material yields- the most powerful device ever created becomes the obvious solution.

          • Joe

            The possibility of a lunar surface “sleeper train” is a different (and potentially more complicated) subject, but for orbital vehicles there are basically three design drivers:

            (1) Minimum required g-level.
            (2) Maximum allowable RPM rate.
            (3) Maximum allowable simulated gravity gradient.

            Have already discussed the first two (though they are still to be determined). The third requires a little explanation.

            Dr. Kerwin suggested that a rotation rate as high a 5 RPM’s might be acceptable. If that is true then a 1 g equivalent can be achieved with a spin radius of only 117 ft. However the perceived gravity would decrease by almost 1% per foot. How will crew react to that? Would it be like land legs/sea legs for sailors or more significant?

            Resolving those issues will likely require testing in an orbital environment. Perhaps with an orbital facility something like the one described in the link below.

            http://www.artificial-gravity.com/JANNAF-2005-Sorensen.pdf

            • Colorado

              With a tether system number three is not really a problem and actually makes it preferable to a torus. However there are some circumstances where a torus would be preferable- such as landing on an icy moon or dwarf.

              If the landing gear support structure is a kind of track, the torus can spin and provide Earth Gravity for the astronauts while they are on the surface of the moon or dwarf planet. Probably have to anchor the landing gear somehow. I cannot imagine such a torus less than several hundred feet in diameter and this actually matches the requirement for a minimally efficient nuclear pulse propulsion disc. A plate and torus closer to a thousand feet in diameter would be far more efficient in regards to propulsion and I would guess be much less likely to cause rotation nausea.

              That is one version of a true space ship- a torus mounted on a shock absorbing superstructure and metal disc. There are several variations on this theme though (the theme being bomb propulsion with a massive spinning water shield).

              Very large diameter spinning-ring-stations take on the character of a hula hoop instead of a doughnut. I do not believe the benefits of a smaller structure are that important for most space applications and the larger the diameter the more habitable and less problems for the astronauts would probably be the rule of thumb.

              • Colorado

                So, in other words, RPM tolerance is not an issue with a tether system but is extremely significant with a torus. The diameter of a torus could be made as large as possible to lower RPM but with a structural penalty that might not be so significant for a space station but would probably be very important if it is a spaceship- depending on the propulsion system. And as I feel obligated to keep repeating, there is only one practical propulsion system for interplanetary travel for the foreseeable future.

                A close-to-thousand-foot-diameter plate for a pulse propulsion system and a matching torus and shock absorbing superstructure to mount on it is a mind-boggling project that most people simply cannot wrap their heads around. But if the plate is fabricated on the Moon in a underground lava tube factory site out of easily acquired ore and much of the mass of the ship is simply water shielding in the torus it becomes less impossible to imagine.

        • James

          As I noted initially for an ‘artificial gravity system’ in space:

          How long would the radius be for 1 “G” of centripetal 13.86 meters per second of acceleration while having only 1 Revolution Per Minute, or RPM, so that most folks would not be bothered by repeatedly going around in a circle and could avoid dizziness and motion sickness?

          The answer is that the radius would be about 894 meters or 2,934 feet. The tangential velocity or ‘circling speed’ of the habitat would be about 93 meters per second or 209 miles per hour or 337 kilometers per hour.

          The total acceleration force that would be experienced by an individual riding in the above 1 ‘G’ and 1 RPM ‘space train habitat’ while testing it at 209 miles per hour, or 337 kilometers per hour, here on Earth on a circular railroad track with an overall diameter of 1,788 meters (or 5,868 feet) can be calculated.

          Take the Earth’s 9.8 meters per second gravitational acceleration squared and add it to the centripetal acceleration 9.8 meters per second squared and you get an answer of 192.08. If I’m doing the math correctly, you then take the square root of 192.08 to get the resultant total acceleration force vector experienced by an individual on that very fast experimental ISRU train. You end up with about 13.86 meters per second of acceleration force.

          So researchers could end up doing lots of the human and small animal testing at ISRU train speeds of “93 meters per second or 209 miles per hour or 337 kilometers per hour” while going around a 1,788 meters (or 5,868 feet) in diameter circle at 1 RPM. This high speed and the 13.86 meters per second of acceleration inside the train strongly suggest that the testing of the 1 ‘G’ and 1 RPM ‘artificial gravity’ space train system should initially be done here on Earth.

          About the fastest I’ve ever driven a car is 95 miles an hour. It seemed like I was flying along with way too much kinetic energy if any thing went wrong.

          Build a 45 degree slanted railroad track that circles around with a diameter of 1,788 meters (or 5,868 feet). Build that very cold tunnel railroad track system near an international research base in Antarctica.

          With 13.86 meters per second of acceleration, there would probably initially be lots of animal experiments done prior to testing humans for long periods of time.

          I would volunteer to ride for a week on that warm and cozy experimental ISRU train going 209 miles per hour on that circular track. I most likely would not need a powered mechanical exoskeleton to get around while experiencing 13.86 meters per second of acceleration. Nonetheless, I’d probably spend much of my ride time floating in a deep bathtub.

          Other acceleration mitigation techniques and systems might also work. Consider the ‘G’ suits worn by some of the military pilots.

          Lots of strong folks would probably volunteer to ride such a fast experimental ISRU train for several weeks, and eventually, some folks could volunteer to ride such a train for several months or even a year.

          Of course doctors would continually monitor the health of every rider. If the doctors were to decide to cut short an individual’s ride for whatever reason, that would be the end of the ‘artificial gravity’ ride on the ISRU train for that person.

          Smaller diameter circular systems with railroad tracks could also be built to test the experimental ISRU train at lower speeds.

          Lots of valuable human “testing for rpm tolerance and adaptation” could be done while also doing extensive long-term testing of such an experimental ISRU ‘artificial gravity’ train system.

          • Colorado

            Good luck with the exoskeleton in the bathtub riding the antarctic train to nowhere James. I thought bombs were a difficult subject but you are making me look positively lucid. Thanks.

          • James

            Yikes! How long would the radius be for 1 “G” of centripetal 13.86 meters per second of acceleration while having only 1 Revolution Per Minute, or RPM, so that most folks would not be bothered by repeatedly going around in a circle and could avoid dizziness and motion sickness?

            That “13.86” meters per second should have been “9.8” meters per second…. Sorry!

  • James

    “Very large diameter spinning-ring-stations take on the character of a hula hoop instead of a doughnut. I do not believe the benefits of a smaller structure are that important for most space applications and the larger the diameter the more habitable and less problems for the astronauts would probably be the rule of thumb.”

    The train rides around inside a much narrower tube that is inside of the “hula hoop” or ‘bicycle wheel torus’. That would minimize the mass that moves around in a large diameter circle…

  • James

    Logic suggests it is a good idea to minimize the amount of mass in motion going around in a circle to minimize spaceship design stresses and thus you might want to keep your massive amount of Galactic Cosmic Ray shielding material ‘immobile’ and just outside of the tube that has the tracks and train inside of it.

    Take a look at the diagram with measurements on page 4 for the proposed Skylab II that is in the NASA article at http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20120016760.pdf

    ‘Making a Deep Space Habitat from a Space Launch System Propellant Tank’ by Brand N. Griffin1, Kriss J. Kennedy, Larry Toups, Tracy Gill, and A. Scott Howe who note concerning Galactic Cosmic Ray shielding, “Experts disagree, but some have suggested a couple of meters of water may do the trick. If this is the case, then a possible solution is to place an ISS US Lab size module within the Skylab II leaving approximately 2 meters between shells (Figure 6)”

    If you imagine ‘stretching’ that 8.5 meter diameter SLS sized tank in the vertical direction and then ‘bend it around in a circle’ to meet the bottom of that SLS sized tank to create a torus, you could then run the train through the “ISS US Lab size module” inner tube and have a rough dimensional outline of an ‘artificial gravity train system’ with useful Galactic Cosmic Ray shielding in the “approximately 2 meters between shells”.

    Yep, the 4 meter wide train would run inside the inner shell, or tube, which has about a 4.5 meter width.

    At 1 RPM, or 1 trip of the train around the inner tube of the torus every minute, even a minimal amount of ‘artificial gravity’ requires a massive and large diameter ‘bicycle wheel’ torus structure.

    If 1 RPM of the train around the wheel is used to create .165 “G” of centripetal acceleration to simulate the gravity of the Moon, the system’s diameter would be about 294 meters or 962 feet. The ‘circling speed’ of the 4 meter wide ISRU train would be about 15 meters per second (or 34 miles per hour or 55 kilometers per hour).If you cut across this 8.5 meter diameter tube and ‘unbent it’ you would get about a 924 meter long and 8.5 meter diameter tube, which would be about the same length as 83 of the above noted 11.15 meter tall Deep Space Habitat from a Space Launch System Propellant Tank.

    Thus even a modest .165 “G”1 RPM train system would probably be far too big, heavy, and expensive of a spaceship design with our current types of rocket propulsion.

    If humans can learn to adapt to higher train RPMs around the torus, that human capability would allow the torus structure to be much smaller.

    If 2 RPM of the train around the torus is used to create .165 “G” of centripetal acceleration to simulate the gravity of the Moon, the diameter the torus would be about 74 meters or 240 feet. The train’s ‘circling speed’ would be about 8 meters per second or 17 miles per hour or 28 kilometers per hour.

    The lower train speed at 2 RPM around the torus could be a significant gain in mission safety.

    Note also that a train that was only 2 meters wide would allow for 1 additional meter of Galactic Cosmic Ray shielding in the above torus because you could then have approximately 3 meters of shielding material “between shells”.

    And if you have prepositioned a tank farm of propellants in an orbit around your destination, then the 3 meters of Galactic Cosmic Ray shielding material “between shells” might not be water. Instead, it might be easy to store propellants that are burned for braking into an orbit around your destination where you would then be able to quickly refill your ship’s propellant/shielding tanks, that are between the “shells”, from the orbiting prepositioned tank farm.

    Extensive and long-term ‘artificial train gravity’ RPM and other related research on Earth is needed in order for engineers to be able to design efficient and healthy environments for spaceships and colonies on the Moon, Mars, and Ceres.