Mars more food or more food?

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samkent

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If you look at the popular ideas on the best way to go to Mars, they all revolve around long travel times. But is this the best way? If you accept this method you have a large hurdles to overcome. Like..<br /><br />Long term food supplies. You can bet they would pack a lot of peanut butter.<br />O2 , Tank after tank. Doesn’t LOX tend to boil off?<br />Long term radiation hazards.<br />Long term zero g issues. <br />Unexpected medical situations.<br />Long term psychological issues.<br /><br />And I’m sure I missed a few. These are not minor things with a simple fix. Why not<br />avoid these things and tackle the main problem head on.<br /><br />Power<br />More rocket power!<br /><br />Ignore the landing aspect for a minute and concentrate on the outbound journey.<br />If you add up the unknowns needed to be solved for a 9 month trip it will clutter your mind. <br /><br />But if you put the major efforts into getting the crew there in a 2-3 week time frame most<br />of the other issues drop off of the list. Imagine this, Orion with a 3 man crew and a beefed up service module mating with a 4-5 section SRB in orbit around the Earth. It would be a kick a$$ ride for a couple minutes then a couple weeks coast. Rendezvous at Mars with a modern version of the LM for a weeks stay on the surface. Then dock with the return SRB , high tail it back home.<br /><br />6 weeks - flag planted – done deal<br /><br />More power! it’s the American way!<br /><br />I have posted this on another fourm but I would like thoughts from here as well.<br />
 
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h2ouniverse

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Or:<br />revolutionary propulsion.<br /><br />Please, for the sake of mankind (and the glory of your country), have NASA resurrect IAC!<br /><br />With envy, from the old side of the pond.<br />Regards.
 
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larper

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1) A simple 5 segment SRB doesn't get you to Mars in 2 weeks. <br /><br />Say 60 million miles straight line of travel to Mars. To get there in 2 weeks, you have to travel at about 180,000 miles per hour. <br /><br />2) Assuming you are traveling at 180,000 mph. How are you going to slow down when you get there?<br /><br />To address your immediate concerns:<br /><br />Long term food supplies: Napolean solved this. We have canned food that lasts years. This is a non problem.<br /><br />O2: Yes, LOX boils off. Fortunately, water doesn't.<br /><br />Radiation hazards: Remember all of that water?<br /><br />Zero G: Ah, now this is a real problem. Probably the biggest of all of them. <br /><br />Unexpected medical situations: We will always face such risks. A non issue, for the most part.<br /><br />Psychological issues: Another real problem. A larger crew, lots of space, and keeping busy will mitigate this hopefully.<br /><br /><br />In my mind, BIGGER is better, not necessary FASTER. Build a BIG ship, that carries lots of water, affords radiation protection, lots of living space, a garden for the food and O2 supplement, and carries a larger, more diverse crew, and that can rotate to generate some gravity, and you can go as SLOW as you want and get there safely. <div class="Discussion_UserSignature"> <p><strong><font color="#ff0000">Vote </font><font color="#3366ff">Libertarian</font></strong></p> </div>
 
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JonClarke

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You have quite rightly identified that one of the biggest issues for Mars missions is logistics. It's not as sexy to talk about toilet paper and toothpaste, but it is just as critical as lander design and propulsion systems. There is a saying in military planning that "amateurs talk tatics, professionals logistics".<br /><br />The logistics for a Mars misison are trivial compared with supplying an off shore oil rig or a polar station. Let alone supporting an army in the field or a fleet at sea.<br /><br />The logistic of Mars misison have been extensively thougt through. It's not as if we are planning something unexpected after all. We have decades of spacefaring experience to base it on. As a result we can calcuate the amount supplies needed. A recent study calculated for a 4 person 2.5 year Mars mission would require:<br /><br /><i>Life support consumables</i><br /><br />Oxygen: 1.76 tonnes (supply on Mars from ISRU)<br />Water: 4.98 tonnes (supply on Mars from ISRU)<br />Food (2/3 water): 7.2 tonnes<br />Nitrogen: 1.5 tonnes (supply on Mars from ISRU)<br /><b>Total: 15 tonnes</b><br /><br /><i>General consumables</i><br /><br />kitchen cleaning supplies: 250 kg<br />Contingency faecal & urine collection bags: 370 kg<br />WCS supplies (toilet paper, cleaning, filters etc): 200 kg<br />Hygiene supplies: 350 kg<br />Disposable wipes: 400 kg<br />Trash bags: 200 kg<br />Operational Supplies: 160 kg<br /><b>Total: 1930 kg</b>: <br /><br />These vary according the type of life support system chosen and the length of the mission. On top of these are the fixed resources, which would be taken regardless of mission duration.<br /><br /><i>Fixed resources</i><br /><br />Clothing: 800 kg<br />Personal hygiene kit: 10 kg<br />Personal stowage/closet space: 400 kg<br />Freezers: 200 kg<br />Conventional oven and microwave ovens MTV: 260 kg<br />Sink, spigot for food hydration and drinking: 60 kg<br />Dishwasher: 80 kg<br />Cooking utensils: 40 kg<br />Waste collection system (toilets): 180 kg<br />Shower <div class="Discussion_UserSignature"> <p><em>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</em>  Arthur Clarke</p> </div>
 
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qso1

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larper:<br />In my mind, BIGGER is better, not necessary FASTER.<br /><br />Me:<br />For crew psychology and comfort, bigger is almost certainly better and bigger is technically doable. Unfortunately, from a cost standpoint, bigger is costlier. Larger LVs are required...or a larger number of smaller LVs would be required to get the vehicle components to LEO.<br /><br />larper:<br />Long term food supplies: Napolean solved this. We have canned food that lasts years. This is a non problem.<br /><br />Me:<br />I'm not sure I'd characterize this as a non problem just yet. Food storage is a big concern among vehicle designers for various reasons. The main one being sheer storage space for 5 or 6 people for missions lasting up to 2 years.<br /><br />I did a graphic novel about a human mission to mars done as realistically as one person (Me) can visualize it. I tackled the food problem by suggesting the vast majority of the food could be TV dinner like. Containerized in packages about that sized. There would be some custom cooked meals for holidays and such but by and large, the TV dinner model as I came to call it...was a way to show theoretically anyway, that taking the food along may be doable without too much added cost.<br /><br />I chose a modified Zubrin plan for getting to mars. One that emphasized keeping the cost of the program down. But in my graphic novel, I showed how the cycle of keeping costs down often balloon into keeping costs from inflating any worse than they already do.<br /><br />Most of the actual concepts for going to mars that I have seen coming out of NASA do not seem to address the food issue in too much detail. Zubrins book "A Case For Mars" IIR the title correctly, mentioned how much mass food and water for a 4 person crew would be.<br /><br />My design got around the problem for the book without extraordinary measures...but then. I'm not a professional spacecraft designer and there could be shortcomings I may have missed. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>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.</em></p> </div>
 
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qso1

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JonClarke:<br />In the mean time we can plan on going to Mars using technology either to hand or developable in the near future.<br /><br />Me:<br />Some of the stuff you mentioned might actually be built less massive for a mars mission. That is, the conventional/microwave oven could come down a bit from 260kg. Or should there be both types if one will do? By MTV, I'm assuming you mean Mars Transit Vehicle. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>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.</em></p> </div>
 
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JonClarke

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For sure! I suspect economies can be made on other items too. Do we really need more than 3 tonnes of machine tools and asociated equipment? Or 2.5 tonnes of medical equipment?<br /><br />But these are the widely accepted baseline figures from Larson and Pranke. They are conservative and worst case.<br /><br />Jon <div class="Discussion_UserSignature"> <p><em>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</em>  Arthur Clarke</p> </div>
 
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holmec

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I would think that if you want to go that route, you might consider launching the food, water, orbital habitat, lander/Mars launcher, and ground habitat all before the crew. that way you can take some time to get all that stuff there and use large amount of fuel to get the Orion capsule to Mars orbit in less time.<br /><br />That could be a good 3-5 launches.<br /><br />Of course that requires Orion to have a supper supped up service module, and the crew would have to launch with the Aries V launcher. <div class="Discussion_UserSignature"> <p> </p><p><font color="#0000ff"><em>"SCE to AUX" - John Aaron, curiosity pays off</em></font></p> </div>
 
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samkent

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If New Horizons attained 36,000 from a ground launched vehicle, 180,000 from an orbiting booster doesn’t seem too far fetched in my mind. Engineers can cook up a viable solution to the speed problem quicker than all of the other issues associated with a 2-3 year journey. Remember I’m talking about getting just the crew there not all of the other equipment.
 
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holmec

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Here's an issue yall missed: waste. As in Biological Waste. With all that food there's bound to be waste and lots of it. What do you do with it? <div class="Discussion_UserSignature"> <p> </p><p><font color="#0000ff"><em>"SCE to AUX" - John Aaron, curiosity pays off</em></font></p> </div>
 
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usn_skwerl

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Deep six it. It'll burn up somewhere... <div class="Discussion_UserSignature"> </div>
 
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holmec

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What if you make a poopy on the ground? <div class="Discussion_UserSignature"> <p> </p><p><font color="#0000ff"><em>"SCE to AUX" - John Aaron, curiosity pays off</em></font></p> </div>
 
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thereiwas

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Weren't we just saying how plants need nutrients in the soil? Gotta recycle. Another tip - mushrooms. Google the name "Paul Stamets".
 
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scottb50

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Recycling would be a necessity, with the cost of getting material to Mars it would be hard to justify wasting anything. <br /><br /> <div class="Discussion_UserSignature"> </div>
 
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usn_skwerl

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Remember that there's at least one bag of pee on the moon. <br /><br />If mass is a concern, throwing trash or waste out before martian landing, or even before orbit insertion would be advantageous, unless they can recycle it efficiently. <div class="Discussion_UserSignature"> </div>
 
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JonClarke

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Not at all.<br /><br />Waste of the voyage to Mars are dried and stored and can be left in Mars orbit. Whether they can be allowed to burn up will depend on the status of planetary protection. But since landing on Mars requires a relaxation of present planetary protection rules I suspect that atmosphereic disposal would be acceptable.<br /><br />On the surface of Mars either dry or wet incineration is a best option. Much like a terrestrial incinolet.<br /><br />On the return from Mars wastes can be dried and stored as part of the radiation protection. They will remain with the hab in solar orbit (in the case mentioned) when the crew enter their earth entry capsule.<br /><br />Jon <div class="Discussion_UserSignature"> <p><em>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</em>  Arthur Clarke</p> </div>
 
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scottb50

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That would be a terrible waste of resources. Even at $1,000 a pound it would be pretty expensive to get everything to orbit let alone to Mars to simply dispose of it.<br /><br />While it maybe rather hard to accept re-using waste we do it all the time here, flush it down the drain and send it to a treatment facility where it is eventually released into rivers and the oceans. Even solids put into landfills ultimately gets released back into the environment.<br /><br />The only real problem is pathogens, but with proper treatment that would be a non-issue. One way to look at is the acceptable levels of waste allowed in foods. Chickens are feed sweepings from under their cages and cows tolerate up to 70% manure in their feed before they refuse to eat it.<br /><br />Primary concern would be water recovery, while there might be available water there also might not be, so far it is conjecture. Setting out with the expectation of finding usable water, and getting to it would be dangerous. I would think a number of missions to Mars would be required that take everything needed with them before the possibility of using native resources could even be exploited. <div class="Discussion_UserSignature"> </div>
 
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thereiwas

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No, you send the first manned mission to a place that has already been verified as having usable water ice by robots. Even better the robots have started refining it into fresh water, oxygen, and methane before the humans are even launched from Earth.<br />
 
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scottb50

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So what, twenty to forty years from now? <div class="Discussion_UserSignature"> </div>
 
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thereiwas

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All the technology exists now. We just have to build it and send it. Best find the ice first. Development of all these stages can proceed in parallel.
 
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scottb50

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I don't think we can do that much until we have people on Mars, just look at the two there now, they ask so many questions that could be answered by a person in minutes. They have done a lot of work in a lot of years but people could match that in weeks or months. <div class="Discussion_UserSignature"> </div>
 
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JonClarke

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<i>That would be a terrible waste of resources. Even at $1,000 a pound it would be pretty expensive to get everything to orbit let alone to Mars to simply dispose of it.</i><br /><br />That depends on the context. Recycling is not the best way to go in all circumstances. The penality of continued resulty has to be weighed against the penality of power, volume, mass and complexity needed for recycling.<br /><br />This is why space missions that run for days to months (Apollo, Skylab, Shuttle, Soyuz, Salyut) use open systems. Those that run for years (Mir, ISS) recycle water and (to some extent oxygen).<br /><br />Full closed biologial life support systems such as you suggest is impractial for permanant settlements. It is not for initial missions, it takes up too much volume (especially the chickens). You design the system for the mission concerned.<br /> <div class="Discussion_UserSignature"> <p><em>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</em>  Arthur Clarke</p> </div>
 
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holmec

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Well, you would have to treat the waste, else you recycle straight and you get sickness. So that would require a <b>waste recycling plant</b>. <div class="Discussion_UserSignature"> <p> </p><p><font color="#0000ff"><em>"SCE to AUX" - John Aaron, curiosity pays off</em></font></p> </div>
 
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j05h

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An option for early waste recycling and other garbage is to just store it as frozen waste on Mars, then recycle it at a later date. This is similar to the "poop bags" that Apollo used, except that you would save it. Waste could be stored on top of early Habs as shielding. <br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>
 
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nexium

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I don't think anyone has dupilated the 5 million pounds of thrust, we used to lift off for the moon missions 37 years ago. I suppose we can build a 7 million pound thrust system to lift off in 24 months in a crash program, but it will need years of debugging, before it is ready to make a likely safe trip to Mars. We tell too many lies now a days to start a crash program for 20 million tons of lift off thrust. We don't know how things will scale up, for sure, and horrible side effects are likely for every design change we make. Even the minor and trivial design changes. Neil
 
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