Mars Architecture

holmec · Aug 5, 2006

>the "bike-centrifuge" that NASA tested recently< nice! How about a circular running track, akin to 2001? <div class="Discussion_UserSignature"> "SCE to AUX" - John Aaron, curiosity pays off </div>

spacester · Aug 5, 2006

We've had many discussions on this subject here. I guess that in my absence there is no chance of building on that past work. I would like to think that in the presence of intellectual honesty, those who remain would at least present alternate viewpoints. Instead, it would appear that their sole motivation is to advance their own particular point of view. Obviously, that remains a false hope. If I had accomplished my mission here, the ethic of processing and presenting ALL viewpoints would have showed up on this thread by now. All I see is ego-driven discussion as opposed to a true search for answers. * I first posted the following many years ago here, and this is at least the 6th time I have re-posted it. I'm not going to spend any time updating it because, well because it's just not worth the effort. Among other things, it appears that high school algebra is beyond the capabilities of everyone here, including the elite scientist. *** For tons of information on the realities of artificial gravity, see: This discussion about the effects of micro-g and the issues regarding artificial gravity and this for all the math you could ever want (scroll down to the conclusions) and then this for an architect's view of what it would be like. Now then, my point is simply that we don’t know the true effects of coriolis cross-coupling in a large radius habitat operating in a micro gravity environment. Of course you will have severe problems in a small radius h <div class="Discussion_UserSignature"> </div>

bushuser · Aug 5, 2006

The spinning tether concept need not be terribly complex...its just a different way of looking at the problem. If you are having to boost several components to assemble in LEO anyway...make the crew module attach to the propulsion module [counterweight] with a tether on a reel. The components latch together for engine firings, and reel out during the cruise portion of the mission.

holmec · Aug 5, 2006

Wow! Thanks for the info Spacester, you gave me a lot to chew on. <div class="Discussion_UserSignature"> "SCE to AUX" - John Aaron, curiosity pays off </div>

holmec · Aug 5, 2006

OK then, so I did some calcs myself. Since Spacester said that 1 rpm gives minimal coreilius effect, I punched in Mars grav, and 1 rpm and got 286.18 meters from fulcrum to floor. That's about 938.91 feet. If you double that for a the other half of the craft, or counter weight, its 1877.82 feet. The only way any craft would be feasable is by a tether! No wheel! Almost 2000 feet of line! You could make it like it were two ships, one cargo and one crew, and put the propusion somewhere etc...etc...etc. So in theory it might be possible. But in practice I still think we need a study on the human factor with small amounts of gravity. In other words what is the minimal gravity needed to sustain a human body without bone loss, and all the other bad side effects of weightlessness?? That is probably the key question to answer before we even think about a long space trip (ie beyond Mars). <div class="Discussion_UserSignature"> "SCE to AUX" - John Aaron, curiosity pays off </div>

scottb50 · Aug 5, 2006

Sounds like what I proposed on the older threads. Multiple, identical, 60x15 foot(18x4.5 meter) cylinders. The Basic Vehicle would use one hub Module, four spoke Modules and two Habitat Modules. This would allow an 18 meter flat floor with whatever gravity desired in the Habitat Modules and cargo or equipment use for the Hub and Spokes. Add multiple Basic Vehicles to each other and the vehicle can be tailored to various needs or disassembled to transfer Modules at a destination. <div class="Discussion_UserSignature"> </div>

j05h · Aug 5, 2006

>> the "bike-centrifuge" that NASA tested recently< /> nice! How about a circular running track, akin to 2001? You could build the centrifuge as a rolling track like that, once the large-scale inflatables are more fully developed. A track centrifuge could also be bike-powered, it might take two people "racing" to keep it spinning. The recent NASA centrifuge was just a framework, very cool looking. If the crew exercises in shifts, they could have G most of the time with a larger track. On food being some critical, huge issue: I worked it out as about 1/3 or 1/2 of Progress module stuffed with Mountain House dry food kits for 30 years of food per person. We could send lifetime's worth of food as a backup. Food isn't a big issue, it's just a bulky dry material. MREs could do it, as could gourment, off-the-shelf camping/survival food. (w/ 30-40yr shelf life) For the other kind of spin-gravity: using a spent 3rd-stage, a winch and several hundred feet of steel cable (or Hoytether), a Mars-bound craft could spin up and maintain a partial-G environment for the outbound trip. These aren't massive structures, we're talking about spinning a 40-80 ton stack at most. Sure would make things like toilets simpler, plus the muscular-skeletal issues. If the mission architecture involves flotilla, the cargo and other hardware travels in freefall, only the manned Hab is spun. This also allows the spin-G Habitat to potentially stay inhabited as an orbital facility while using a "James Cameron" style surface architecture. The engineering for a Hab+3rdStage should be modest and attainable in the medium term. It could be a third-generation feature of Bigelow inflatables. This arrangement is probably satisfactory for a 6 person crew. Anything larger (multiple TransHabs, dozens of crew) would have to use a different spin method, maybe a giant truss or bike-centrifuges in modules. Josh <div class="Discussion_UserSignature"> <div align="center">We need a first generation of pioneers. </div> </div>

JonClarke · Aug 5, 2006

"At the moment we don't really know. First off, if we were developing a Mars craft today, then VASIMR type propulsion might not offer advantages over NTR or chemical." If we don't know what the advantages are, why develop it? We can go to Mars using existing propulsion technology. If other programs or even private industry develop more advanced propulsipon then fine, they can be used. But VASIMR or other exotic technologies are not neccessary for baseline planning. "But going to Mars is still at best, 20 years or more away. " Agreed. "In that time, private industry might change the access to LEO, by bringing down costs, enough to justify the VASIMR type propuslion system development. " There is that word again, might. Private industry also might not. In other words neither private industry nort the technology can be relied upon. So, is it better to develop Mars mission concepts on what might (or might not) be available, or to do so on technology that either exists or is likely to exist by that time? "Among the circumstances that might make the investment worthwhile, reduced transit times means reduced exposure to potential solar flare activity and if future studies reinforce the current one on bone mass loss. Then a combination of excercise, short transit times, diet, ect. could justify the investment." Bone mass loss is not a fundamental problem now. There is no pressing biomedical need to shorten the transit time for the initial sequence of Mars missions. "Once again, I don't think we are really ever going to send anyone to Mars...not the U.S. anyway because we have become a society too concerned with how much we spend on NASA human space flight while deficits run rampant." That's just unjustified negativity, IMHO. But the fact that there is this negativity about is one reason why returning to the Moon is important for the US. If the US can return to the Moon then it <div class="Discussion_UserSignature"> Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars Arthur Clarke </div>

JonClarke · Aug 5, 2006

JC wrote: "Low spin rates are engineeringly complex. In other words costly. They still would require adapatation from the crew and reapatation afterwards. We have no idea how long this takes or how well people do it. " You wrote: "How do you know this?" How do I know this? The technical complexity you have already answered. You need to develop the technology that can unreel tethers that can support many tonnes and are near 600 m in length. You need to develop the ability to spin and despin such structures. Work out operational proceedures for emergency EVAs under such conditions, design spacecraft systems - waste management, cooling, systems that function equally well under zero G and spin G. We have no experience in this, it would have to be developed, tested, and retested. This all equals money and time to solve a problem which we already know does not need to be solved. For the human side of things, the probelm is we don't know. Finding out to the level that would inspire confidence from the biomedical fraternity would take ground simulators, preliminary space missions, special space stations for the research. Once again time and money and time to solve a problem which does not need to be solved. You wrote: "Can you please elaborate on crew ineffectiveness. What does it do to the crew? They can't sleep? read? chew gum? they fall? disorientation? what?" At high spin rates there are vestibular disturbances that effect vision, coordination, movement. It might be that after a few days or weeks that people could adjust to this. But how long would it take for people to readjust? A similar amount of time? We don't know. Answering this question will take time and money. We already know that people after 6 months in space, can land spacecraft look after themselves, carry out light duties and within a week undertake full duties. This is good enough for mission where people will be spending 77 weeks on the <div class="Discussion_UserSignature"> Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars Arthur Clarke </div>

qso1 · Aug 6, 2006

holmec: Which commercial activities (eg tourism, He3 mining, low-grav manufacturing etc) will be the first to attract the private industry in their numbers and how soon? Me: I for one would recommend some kind of artificial gravity on any mars vehicle except possibly VASIMR type propulsion vehicles. Or other vehicles with short transit times. But providing that gravity would entail additional cost in terms of ship configuration as I will attempt to demonstrate with the illustration as reference. 1. The most basic configuration for a mars craft would be the zero "G" habitat mother ship with lander docked to it at one end and propulsion at the other. 2.....Simplest zero "G" configuration would be tethered. Thetherings cost lies in how the mechanism at the other end will actually create the necessary spin, and how to despin for docking operations. And in designing a tether strong enough for spin and despin operations. 3.....A more complex method involves spinning one or more hab modules. Some kind of complex spin mechanism would be required. One that could also be spun and despun as required. How much additional cost would be added is not known at this time but in the number 2 configuration, additional cost is incurred by the addition of a tether made of extremely strong material to ensure it does not snap during gravity generation. The number 3 configuration, Design the habs on a semi production line basis, the two additional habs plus spin mechanism would raise the craft cost considerably. The zero "G" hab could be deleted to lower costs but in nearly every proposal involving manned spacecraft, they start ambitiously and get worked down. An example being NASA wanting to replace the shuttle. The X-33 aerospaceplane lead to VSE CEV capsule. <div class="Discussion_UserSignature"> My borrowed quote for the time being:There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened. </div>

holmec · Aug 6, 2006

>You need to develop the technology that can unreel tethers that can support many tonnes and are near 600 m in length. You need to develop the ability to spin and despin such structures. Work out operational proceedures for emergency EVAs under such conditions, design spacecraft systems - waste management, cooling, systems that function equally well under zero G and spin G. We have no experience in this, it would have to be developed, tested, and retested. This all equals money and time to solve a problem which we already know does not need to be solved. < Most all this technology already exists. Just have to apply different materials and get masses right. Technology of bridges and cranes not much more. The only real problem is the tesil strength, but at less than 1G your tonnes and stresses are reduced. />I am sure it's technically possible to do all this. But why bother for a Mars mission? It's not necessary, we have known this for nearly 30 years. < But never put into practice! We need this technology. Maybe not strictly for Mars, but will we stop at Mars? It seems to me the Mars is the limit as far as distance is concerned at traveling weightless. What about deep space stations and raw material processing plants? They need this know how. NASA may be paving the way to planteary human planetary exploration, but the private commercial industry will be needing technology like this, and most of the know how for them also comes from NASA and other space agencies. But for Mars, it would be a safe guard, and you also could leave an astronaut in orbit. Since the RSA and NASA agreed that 6 months should be a standard limit for crew on the ISS, I believe thats going to be the future SOP. />At high spin rates there are vestibular disturbances that effect vision, coordination, movement. It might be that after a few days or weeks that people could adjust to this. But how long would it take for people to readjust? <div class="Discussion_UserSignature"> "SCE to AUX" - John Aaron, curiosity pays off </div>

holmec · Aug 6, 2006

Interesting. I always thought about a stationary track though. So as you run you create your own centrifuge, thus gravity. <div class="Discussion_UserSignature"> "SCE to AUX" - John Aaron, curiosity pays off </div>

holmec · Aug 6, 2006

>Is it just me, or does it seem inherently incongruous that spinning two habs at the end of a tether or a sturdy truss is a steeper engineering climb than going to Mars? I've read from more than one poster on this thread how essentially long reelable tether technology supporting large weights requires so much study that it is a non-starter. As if there were no such thing as a tower crane, or its operation is poorly understood albeit useful and crucial all these decades. < Ahhh....common sense...its always amazing. I thinke amusement parks had rides that do simular things at 1G+ and 1rpm+. I seem to remeber being in one spining in a small car with other 19 cars. The centrifuge started on the horizontal, then it lifted with this amazing technology called hydrolics to stop at the vertical perpendicular to the earth surface. As I spun around I went from I think 2Gs (at the bottom) to 0G (at the top). And that was in the late 1970s. <div class="Discussion_UserSignature"> "SCE to AUX" - John Aaron, curiosity pays off </div>

JonClarke · Aug 6, 2006

You wrote: "Most all this technology already exists. Just have to apply different materials and get masses right. Technology of bridges and cranes not much more. The only real problem is the tesil strength, but at less than 1G your tonnes and stresses are reduced." The technology exists but the hardware does not. Devloping it will be costly in time and money. Why had to the cost of developing a Mars mission when it's not necessary? I wrote:"I am sure it's technically possible to do all this. But why bother for a Mars mission? It's not necessary, we have known this for nearly 30 years." You wrote: "But never put into practice!" What haven't we put into practice? The fact that we can routinely flying missions of 6 month or? There has been more than 30 missions do exactly that. You wrote: "We need this technology. Maybe not strictly for Mars, but will we stop at Mars? It seems to me the Mars is the limit as far as distance is concerned at traveling weightless. What about deep space stations and raw material processing plants? They need this know how. NASA may be paving the way to planteary human planetary exploration, but the private commercial industry will be needing technology like this, and most of the know how for them also comes from NASA and other space agencie" I am not opposed to this research in general. As you say, it is going to be useful. Therefore it should be investigated. But saying it is something we must have for a Mars mission is simply wrong. you wrote: "But for Mars, it would be a safe guard, and you also could leave an astronaut in orbit. Since the RSA and NASA agreed that 6 months should be a standard limit for crew on the ISS, I believe thats going to be the future SOP." But it is a safeguard that is not needed. NASA does not think that spin gravity is necessary. there is no mention it it in the present DRM. RSA does not think it is necessary - look at there Ma <div class="Discussion_UserSignature"> Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars Arthur Clarke </div>

holmec · Aug 9, 2006

>Definitely! But this research will require a whole dediated station in earth orbit. It's hard enough to get support for one station in earth orbit let alone a second one. < Yes I see your point. Not for Mars. Perhaps for something more distant. However perhaps such research could be conducted is sevral parties were involved, NASA, companies like Biglow, Univercities...etc. <div class="Discussion_UserSignature"> "SCE to AUX" - John Aaron, curiosity pays off </div>

holmec · Aug 9, 2006

>take a dump or two.< Wow that would be some epiphany toilet (see scrubs). <div class="Discussion_UserSignature"> "SCE to AUX" - John Aaron, curiosity pays off </div>

j05h · Aug 9, 2006

> However perhaps such research could be conducted is sevral parties were involved, NASA, companies like Biglow, Univercities...etc. If there is a need for large-scale spin, it will be developed. It's not a deal-breaker for short Mars flights. Bike-centrifuge is still an intriguing interim solution. I think large-scale spin will be required for orbitting stations or Phobos base. There are solutions that range from DIY to pre-built to manufacture-in-place. Josh <div class="Discussion_UserSignature"> <div align="center">We need a first generation of pioneers. </div> </div>

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