Bill Phil Posted October 24, 2016 Share Posted October 24, 2016 3 hours ago, NeverEnoughFuel!! said: Well 10% doesn't seems much on paper... but 10% were also approximately Allied loses on D day in Normandy including dead and wounded (in our case dead and cured)... out of roughly 156 000 troops in total, 10%, or 15 600 payed the price in life or a limb (latest research counts about 4500 dead and rest of it wounded), and it was a bloodbath (very acceptable from military point of view, but let's not forget, military tolerates loses up to 25%, and at the time predictions for famous paratroopers were 70% dead) ... Forgive me but I don't like those odds... the idea of a slow bullet who will catch me 2-3 years after the (highly hypothetical, probably not in my lifetime) return from Mars with odds of survival like a guy on Omaha beach? Forget it... you would be very good general, but i wouldn't like to be in your colonization program... You're already at risk of getting cancer over your lifetime. Lifetime risk is a measure of how likely you are to get something in your lifetime. So, if a hypothetical Mars expedition member is 30 years old, and their cancer risk increases by 2%, it means that they're slightly more likely to get cancer over the rest of their lifetime. They may get killed in a car accident first. Or they may live to 85, and then get cancer. Or they might get it sooner. It's lifetime risk of getting cancer (or some other health issues), not risk of death. Many people who get diagnosed with cancer live healthy lives, and many don't. Risk of dying from any type of cancer is already 22.62% for males and 19.13% for females. But what about just developing cancer, not dying from it? Roughly double the death values. (of course these are average risks of the US population, risk on an individual basis could be very different) This means that it's already worse than Omaha Beach just by being alive. Source: http://www.cancer.org/cancer/cancerbasics/lifetime-probability-of-developing-or-dying-from-cancer Link to comment Share on other sites More sharing options...
Northstar1989 Posted October 24, 2016 Share Posted October 24, 2016 23 hours ago, Gkirmathal said: @Northstar1989 Although off topic, a while back you were talking about a separate Mars LMO lander system. Might be someone is working on just such a design and system as we speak. Check out the following article: http://www.thespacereview.com/article/3085/1 This is *exactly* what I think Musk and NASA both need to be aiming for... 20 hours ago, Serpens Solidus said: A 10% increase in lifetime cancer risk is not quite a 10% chance of dying. Unless we're talking about percentage points. It's a roughly 3% lifetime risk of developing cancer NASA deems unacceptable, which is stupid, because you already have around a 40% chance of developing cancer just by being alive... Of course, the most likely types of cancer from rad exposure are aggressive skin cancers, bone cancers, and leukemia- but even so none of those are necessarily a death-sentence. The astronauts would increase their risk of cancer a lot more just by taking up smoking... Ignoring certain earlier fear-mongering, this risk is due to rad from both cosmic rays AND solar storms, combined. And we're perfectly capable of building a heavily-shielded plastic (RFX1) solar storm-shelter into the middle of the craft or near the fuel tanks and engines, and surrounding it with your food and water supplies for extra protection. Building the rest of the spacecraft structure out of RFX1 would also provide some baseline protection against cosmic rays (aluminum is *terrible* for this because it emits a lot of secondary radiation, which is almost as dangerous as the cosmic rays it absorbed), and save weight anyways, as it is both stronger *and* lighter than aerospace-grade aluminum. Which not only means better rad protection, it also means much cheaper and lighter-weight construction with better safety-margins (the safety margins are what allow for cheaper construction- when you've overenginerred something and are not riding the absolute limit of what is physically possible, you don't need to be *nearly* as precise about the exact number of millimeters of thickness of structural elements...) Regards, Northstar 18 hours ago, tater said: @NeverEnoughFuel!!, that's not how the risk works. Your cancer risk over your entire life for the relevant cancers might be 5%. A 10% increase makes the risk 5.5%. We males will almost all end up with prostate cancer, for example. But when you are 90 with it, something else will likely bump you off first. Increasing cancer risk might not be a big deal. Heck, if their diet is well curated and they stay thin, Mars---radiation and all---could be a net positive, lol. Unfortunately, I think it's a 3% or 10% increase in risk in absolute terms (that is, 3% of all people developing cancer specifically due to rad exposure early enoygh in life for it to be a problem) NASA meant when they drew the 3% line-in-the-sand, not a 3% increase in risk. Either way, though, your baseline risk of developing cancer early enough for it to be noticed is around 40% anyways. And something of 80-90% of males are found to have prostate cancer when they die of violence or age-related ailments when advanced in age, even though it was never a problem because something else bumped them off first... I understand NASA's concern- astronauts getting cancer is bad PR- but I think it's wholly inappropriate when you're talking about the fate of the human race here... (like Musk, I don't believe mankind will survive long as a nuclear-armed single-planet species) Regards, Northstar Link to comment Share on other sites More sharing options...
tater Posted October 24, 2016 Share Posted October 24, 2016 Well, the eggs in one basket being solved is rather a long way off (that requires a genetically diverse population on Mars that is 100% self-sufficient). Also, I think that their exposure limits are as employers, lol. Hence my OSHA reference. Link to comment Share on other sites More sharing options...
NeverEnoughFuel!! Posted October 24, 2016 Share Posted October 24, 2016 (edited) 3 hours ago, Northstar1989 said: It's a roughly 3% lifetime risk of developing cancer NASA deems unacceptable, which is stupid, because you already have around a 40% chance of developing cancer just by being alive... Of course, the most likely types of cancer from rad exposure are aggressive skin cancers, bone cancers, and leukemia- but even so none of those are necessarily a death-sentence. The astronauts would increase their risk of cancer a lot more just by taking up smoking... Ignoring certain earlier fear-mongering, this risk is due to rad from both cosmic rays AND solar storms, combined. And we're perfectly capable of building a heavily-shielded plastic (RFX1) solar storm-shelter into the middle of the craft or near the fuel tanks and engines, and surrounding it with your food and water supplies for extra protection. Building the rest of the spacecraft structure out of RFX1 would also provide some baseline protection against cosmic rays (aluminum is *terrible* for this because it emits a lot of secondary radiation, which is almost as dangerous as the cosmic rays it absorbed), and save weight anyways, as it is both stronger *and* lighter than aerospace-grade aluminum. Which not only means better rad protection, it also means much cheaper and lighter-weight construction with better safety-margins (the safety margins are what allow for cheaper construction- when you've overenginerred something and are not riding the absolute limit of what is physically possible, you don't need to be *nearly* as precise about the exact number of millimeters of thickness of structural elements...) Regards, Northstar Unfortunately, I think it's a 3% or 10% increase in risk in absolute terms (that is, 3% of all people developing cancer specifically due to rad exposure early enoygh in life for it to be a problem) NASA meant when they drew the 3% line-in-the-sand, not a 3% increase in risk. Either way, though, your baseline risk of developing cancer early enough for it to be noticed is around 40% anyways. And something of 80-90% of males are found to have prostate cancer when they die of violence or age-related ailments when advanced in age, even though it was never a problem because something else bumped them off first... I understand NASA's concern- astronauts getting cancer is bad PR- but I think it's wholly inappropriate when you're talking about the fate of the human race here... (like Musk, I don't believe mankind will survive long as a nuclear-armed single-planet species) Regards, Northstar Well, I red Musk's AMA on Reddit , several people asked him the same thing we are arguing here, and he didn't reply... why? Maybe because he has no answer? If he had an answer, I'm sure he wouldn't/couldn't hold it up if for nothing else than vanity as a reason, to blabber about how he find a solution and NASA didn't... As I said before, we need much more than one Musk to get off this rock... anybody who wants to trust him with their lives/health and fly there in a cardboard box... go ahead it's your choice... I'm not going to argue anymore, I will let Neil deGrasse Tyson do it for me http://www.fool.com/investing/general/2016/03/27/neil-degrasse-tyson-to-elon-musk-spacex-delusional.aspx this one too... Edited October 24, 2016 by NeverEnoughFuel!! Link to comment Share on other sites More sharing options...
Mitchz95 Posted October 24, 2016 Share Posted October 24, 2016 (edited) 2 hours ago, tater said: Well, the eggs in one basket being solved is rather a long way off (that requires a genetically diverse population on Mars that is 100% self-sufficient). Also, I think that their exposure limits are as employers, lol. Hence my OSHA reference. We have to start somewhere... And I doubt anyone willing to risk the very tangible dangers of space travel and Mars colonization would have a problem with a slightly increased chance of cancer. Edited October 24, 2016 by Mitchz95 Link to comment Share on other sites More sharing options...
Northstar1989 Posted October 24, 2016 Share Posted October 24, 2016 (edited) 2 hours ago, NeverEnoughFuel!! said: Well, I red Musk's AMA on Reddit , several people asked him the same thing we are arguing here, and he didn't reply... why? Maybe because he has no answer? If he had an answer, I'm sure he wouldn't/couldn't hold it up if for nothing else than vanity as a reason, to blabber about how he find a solution and NASA didn't... I not only read, but submitted a couple questions on that AMA, and they were on entirely different topics, but not answered. Why? Because there were literally HUNDREDS of questioms asked there. The only vain thinking here is your assumption that just because he didn't select the questions YOU wanted him to answer, that means he didn't have an answer for them. Your argument holds no water. Speaking of which, using the crew's food and water as a radiation shield is one of the possible solutions that's been proposed before- by Robert Zubrin (obviously you'd need additional shielding beyond this, but it helps), and it's something NASA is considering. In fact there are literally dozens of possible solutions NASA is thinking about, and your lack of awareness of the optimism many NASA researchers hold about the subject does *not* constitute actually thinking there is no solution in site.. Your description of Musk, on the other hand, betrays an egotism that you really should work on. Saying a famous, intelligent, *highly* successful billionaire who started from nothing, immigrated to the USA, and built not one or two, but FOUR wildly successful companies (SpaceX, Tesla Motors, Solar City, and PayPal) and is famously humble in the way he deals with his own employees and interviews is an incompetent braggart who can't help but mouth off, shows that you are unable to keep your own braggadacio in check. I would strongly suggest you stop talking about your personal impressions of Musk and start talking about the topic of this thread (SpaceX), because baseless personal attacks on somebody so much more successful than yourself only make you look jealous.. 2 hours ago, NeverEnoughFuel!! said: As I said before, we need much more than one Musk to get off this rock... anybody who wants to trust him with their lives/health and fly there in a cardboard box... go ahead it's your choice... I'm not going to argue anymore, I will let Neil deGrasse Tyson do it for me http://www.fool.com/investing/general/2016/03/27/neil-degrasse-tyson-to-elon-musk-spacex-delusional.aspx this one too... Neil DeGrasse Tyson is famous for having an ego the size of a planet. He regularly says things that are wildly scientifically inaccurate, and yet there are no famous people who are safe from his critiques. He's more of a celebrity than a scientist, in the flavor of Dr. Oz, and I very much suggest you find a more credible source if you're looking to level a legitimate criticism against Elon Musk. Even Bill Nye would be far more credible- at least he's humble (in fact I've met the guy when I was a student- like myself he's a Cornell alumni, though much older- and he's quite a humble person)- and I hear he's a bit skeptical of Musk's plans as well... Also, Tyson didn't even *mention* Musk or SpaceX in the video you posted (wrong one, clearly). Finally, "fool.com", seriously? THAT'S what you consider a legitimate source? Not to mention, their article is impeccably dumb. They literally calculate the cost-per seat to Mars by taking the initial R&D cost for the ITS, multiplying it by a factor of 3 because they believe it's over-optimistic, and then just dividing it by the 100 seats on a single ITS launch. That's just stupid, stupid, stupid of them. It's as if they never even read anything of Musk's plan (which they probably didn't). For one, they're completely ignoring that each ITS gets re-used 11 times (for 12 total uses)- so they would have to divide by 1200 if they only assumed Musk built one ITS ever. But of course, that's not his plan- it's incredibly obvious Musk intends to build dozens and dozens of them, and banks are well aware of the difference betwern "sunk" and marginal costs- so even if Musk was firced to pay for R&D out of his personal fortune banks would have no issue lending hom money to build additional ITS's after the first launch proved it could reach Mars (and probably long before that). Additionally, there are all sorts of tax-credits and write-offs Musk can take advantage of to help pay for R&D. That's not even counting that NASA is likely to give him some more grants, like the Air Force already did for the Raptor engine, or that SpaceX is likely to start selling tickets for IRS launches years in advance. In the end, that article is deserving of the website's name- and only a fool would take it seriously. I mean no offense, but you *really* need to work on your criticisms if those are the best sources you can come up with (Tyson, yourself, and a website literally called "fool.com"). Regards, Northstar Edited October 24, 2016 by Northstar1989 Link to comment Share on other sites More sharing options...
Nibb31 Posted October 24, 2016 Share Posted October 24, 2016 11 hours ago, Northstar1989 said: No, everything I said is fully supported by NASA and other organizations' research. I just happen to look at the data and draw the line somewhere different than NASA. NASA thinks a 3% lifetime risk of cancer is unacceptable, I say a 10% lifetime risk of cancer is acceptable when we're talking about colonizing another planet... When it comes to colonization, you are including children. Imposing a 10% lifetime risk (which would actually be much higher for young children) can be considered unethical at best and probably criminal. There's still the ethical and legal question about imposing dangerous working conditions on the people you send. It will take decades if it ever reaches the $200000 and that won't include the cost of life support and habitation on Mars, so most people will be sent as employees with their company paying for the ticket, like expats, oil rig workers, antarctica scientists, and so on. These people might be volunteers, but so were coal-miners or people who worked with asbestos. We all know how that turned out it terms of life expectancy. Link to comment Share on other sites More sharing options...
Bill Phil Posted October 24, 2016 Share Posted October 24, 2016 5 hours ago, Northstar1989 said: I don't believe mankind will survive long as a nuclear-armed single-planet species The trouble with that is the fact that planets are very easy targets to hit. We still wouldn't live long as a double, even triple planet species. And we needn't be nuclear-armed, either. Remember the Chelyabinsk meteor? Its explosion was about 500 kt. More than the bombs used in WWII. What if had hit Chelyabinsk instead of air bursting and breaking windows? Just a small nudge could've done it. A nuclear war on Earth would be far less devastating than asteroid drops between two planets. At least we have to build and develop the nukes first. But the asteroids are already there. So, since SpaceX wants to colonize Mars SoonTM, it might be a good idea to develop effective asteroid defense systems. For both planets. Link to comment Share on other sites More sharing options...
Nefrums Posted October 24, 2016 Share Posted October 24, 2016 The cancer risk is irrelevant. What is relevant is the life expectancy. And this will be very very low for early colonists, space is dangerous. If we disregard he obvious dangers with space travel, (like the rocket blowing up, craching into mars, pressure failure of the habitat, power/oxygen faliure, etc.) and only look at the other things that affect life expectancy, it would be fairly easy to get better life expectancy even with the increased cancer risk from radiation. Banning smoking and rationing food would have to be done on a mars colony, and that would more than competence for the increased radiation exposure, in terms of life expectancy. Link to comment Share on other sites More sharing options...
Northstar1989 Posted October 24, 2016 Share Posted October 24, 2016 (edited) 10 hours ago, Nibb31 said: When it comes to colonization, you are including children. Imposing a 10% lifetime risk (which would actually be much higher for young children) can be considered unethical at best and probably criminal. Musk explicitly stated that children would be barred from flying on the ITS in the early years, becayse he feels they would be too much of a drain on the colony. So problem solved. In fact you never would have raised this as an issue if you actually did your homework before making wild statements. On that note, the risk of a cancer is much less than the risk from working in a mine, or even the risk from smoking cigarettes. This is just more scare-tactics, with absolutely no foundation in facts. 9 hours ago, Nefrums said: Banning smoking and rationing food would have to be done on a mars colony, and that would more than competence for the increased radiation exposure, in terms of life expectancy. Absolutely. It's actually kind of laughable, really. Some peopke are terrified of space radiation, but do far more to shorten their life-expectancy than cosmic radiation from a Mars joyrney ever could every time they light up a cigarrette, or eat their ninth double cheeseburger with extra cheese that week... Things like micrometeorites and structural failure of pressurized habitats ate much greater dangers for a Mars journey than backgroun cosmic radiation. The only *real* danger from radiation worth worrying about that much comes from solar storms, and it's easy enough to create a tiny, cramped, *heavily*-shielded (preferably, using plastics or water, due to their superior shielding mass-effectiveness) "storm bunker" for the ITS's 100-man crew to deal with that (in fact the larger your crew the relatively easier it is to create a sufficiently-shielded shelter with a given mass per-person, due to the Square-Cube Law...) Regards, Northstar Also worth noting- Solar Particle Events last hours to days (usually only a couple days at most). They are hardly instant-death, and what's more, can usually be predicted. So it's easy enough to put radiation sensors around the ITS habitat, and fire off warning klaxons telling the crew to head to the radiation shelter if the spacecraft is caught by an unexpected SPE scientists on Earth failed to forecast... You'd experience maybe one SPE on a Mars transfer most of the time, sometimes none if you were lucky- two if you weren't. So asking the crew to hang out in the radiation shelter for a day or two during a particularly long SPE would hardly be a frequent occurrence. You might even hold werkly solar-solar-storm drills on the spacecraft, much like you have fire drills on Earth, to test the warning systems and make sure people don't panic if there's an actual solar-storm emergency and know to calmly head to the rad shelter. It would give the crew something to do to keep them busy and stave off boredom during the long journey, while building crew discipline and organization, at the very least... Northstar Edited October 24, 2016 by Northstar1989 Link to comment Share on other sites More sharing options...
Nibb31 Posted October 24, 2016 Share Posted October 24, 2016 (edited) 6 hours ago, Northstar1989 said: Musk explicitly stated that children would be barred from flying on the ITS in the early years, becayse he feels they would be too much of a drain on the colony. So problem solved. In fact you never would have raised this as an issue if you actually did your homework before making wild statements. So what is it then ? Are we talking colonization (which is a long term goal that won't happen until we actually develop the technology to make it possible) or are we talking short term outpost/exploration (which involves temporary stays, huge construction efforts and high upfront costs). No children specifically rules out colonization. It's one or the other. You can't have it both ways. There are at least two major phases to this so-called colonization effort. The one that Musk talks about is when there are thousands of BFS with an actual destination already built and a low ticket price where people settle on Mars with their families, which is at best decades away. This is the building phase, where cost and risk are high, where infrastructure, supply chains, and a whole economy need to be built from scratch. And this is all handwaved away. The funny thing is that Musk's ITS is specifically aimed at the 2nd phase. It's rather suboptimal for the 1st phase, which incidentally is the one that he will be facing first and is likely to last for decades. He's building a jumbo jet for settling the far west. Quote On that note, the risk of a cancer is much less than the risk from working in a mine, or even the risk from smoking cigarettes. This is just more scare-tactics, with absolutely no foundation in facts. More handwaving. We simply don't know what the biological risks are because we haven't even had people living more than a year or two exposed to low gravity, isolation, and cosmic radiation. Radiation is only one of the unknowns, and it will have an effect. For all we know, it simply might not be possible to have children on Mars, which will make the whole colonization idea moot. Edited October 24, 2016 by Nibb31 Link to comment Share on other sites More sharing options...
tater Posted October 24, 2016 Share Posted October 24, 2016 (edited) Yeah, step one is not Red Dragon, IMO, step one would be putting up a couple BA-220s on a tether, and spinning them up to get 0.38 g, then throw people in there for over a year. We are still getting data about human factors in microgravity, and we basically knew nothing before we started flying people for long time periods. We know ZERO about any environment between 0g and 1g. So we need data on immediate effects, AND we need data on mammals raised in that lower environment, too. If 0.38g is not enough, that's a show-stopper all by itself. Edited October 24, 2016 by tater Link to comment Share on other sites More sharing options...
Northstar1989 Posted October 24, 2016 Share Posted October 24, 2016 (edited) 7 hours ago, Nibb31 said: More handwaving. We simply don't know what the biological risks are because we haven't even had people living more than a year or two exposed to low gravity, isolation, and cosmic radiation. Radiation is only one of the unknowns, and it will have an effect. For all we know, it simply might not be possible to have children on Mars, which will make the whole colonization idea moot. Don't tell a biologist what we do and don't know about radiation exposure. Actually, we *DO* know the expected rad doses, and we *DO* have prior experience with the health effects of similar and even greater doses. We can expect an increased risk of cancer and some moderate percentage reduction of fertility, but nothing we can't deal with... We ALSO know the health effects of 4-6 months spent in 0 g. That's because we regularly send ISS astronauts up for 6 months to a year. Musk's plan only calls for a travel-time of 3-5 months, and Zubrin's revised plan calls for an average transit time of 6 months. NOBODY is suggesting people spending "more than a year" in microgravity (Mars *HAS GRAVITY* of its own- and speaking as a biologist I can make an educated guess it's probably enough for comparatively normal health- it's enough for fluids to settle and drain downwards, and that's basically the most important thing) so quit your irresponsible fear-mongering and start talking facts. Musk said that children won't be allowed initially. That doesn't mean some won't eventually be conceived on Mars by some of the younger parents in their 20's to 30's sent there. The most difficult problem will actually be convincing these colonists to have ENOUGH children when the time is right, since your typical 1.9 children per mother for developed nations (where life is much easier) won't lead to any population-growth... Regards, Northstar Edited October 24, 2016 by Northstar1989 Link to comment Share on other sites More sharing options...
StarStreak2109 Posted October 24, 2016 Share Posted October 24, 2016 (edited) --- Edited October 24, 2016 by StarStreak2109 Link to comment Share on other sites More sharing options...
Northstar1989 Posted October 24, 2016 Share Posted October 24, 2016 2 hours ago, tater said: Yeah, step one is not Red Dragon, IMO, step one would be putting up a couple BA-220s on a tether, and spinning them up to get 0.38 g, then throw people in there for over a year. We are still getting data about human factors in microgravity, and we basically knew nothing before we started flying people for long time periods. We know ZERO about any environment between 0g and 1g. So we need data on immediate effects, AND we need data on mammals raised in that lower environment, too. If 0.38g is not enough, that's a show-stopper all by itself. We regularly send people to the ISS for 6-12 months, and that's longer than it will take to get to Mars. And, speaking as a biologist, it is *HIGHLY* unlikely 38% gravity would lead to any substantial ill health-effects. What do you think would happen, at 0.38 g that would be so bad, exactly? It's enough for fluids to settle and drain, and to load bones with several dozen pounds of weight (plus, it's not hard to enforce exercise regimens on Mars where people lift even heavier loads to offset some of the *moderate* expected decreases to bone and muscle density), which is really all that's necessary for human health... Regards, Northstar Link to comment Share on other sites More sharing options...
tater Posted October 24, 2016 Share Posted October 24, 2016 It's unknown. There is no substitute for actual data, and LEO is a better place to do it while we are biding time (it's not like ITS will actually be flying any time soon, IMO). Link to comment Share on other sites More sharing options...
Elthy Posted October 24, 2016 Share Posted October 24, 2016 But how would you test it? You would have to design a spacestation specificly for that purpose, launch it, launch people to it, spin it up, spin it down every time you want to resupply them etc. I would assume the costs to be in the order of 10 billion dollars, which would still be very cheap compared to the ISS. And then you know that e.g. 6 months of 0,38g propably dont do anything, but what about 60 years? Way simpler to find out on Mars... Link to comment Share on other sites More sharing options...
Nefrums Posted October 24, 2016 Share Posted October 24, 2016 There is only one way to know for sure. Send a couple of thousand people to live there for 20 years. Sure they will probably all die, but what is the problem with that? It is not like anyone will be forced to go. And there will still be hundreds of thousand of people that will what to go on the next trip. Link to comment Share on other sites More sharing options...
Northstar1989 Posted October 25, 2016 Share Posted October 25, 2016 (edited) 7 hours ago, Nefrums said: There is only one way to know for sure. Send a couple of thousand people to live there for 20 years. Sure they will probably all die, but what is the problem with that? It is not like anyone will be forced to go. And there will still be hundreds of thousand of people that will what to go on the next trip. Haha, you must think you're very clever. You're not. Everybody dies eventually, but there is zero reason to think that Mars gravity will have anything to do with it. Just because something is unknown or new doesn't make it dangerous, and the human body is incredibly resilient- capable of surviving a lot more than you think. Collecting data with a rotating habitat in LEO would be a pointless waste of money. Sure, we don't know for sure what will happen to the colonists' bodies in 0.38 g. But we have a pretty good idea, since we're quite sure it's enough for most physiological processes except maintaining Earth-like bone and muscle density (both will atrophy somewhat- but nothing like in microgravity). And there's nothing we can do to change the gravity on Mars anyways, so there's no point wasting millions of dollars on a short-term study that won't tell us anything informative, or the kind of long-term study that might- but would take hundreds of millions of dollars and 20 years of data-collection, and end up getting confounded by 100 variables you can't accurately match to Mars just by spinning a station in orbit anyways... We also don't know for sure what will happen if you stand on the moon alone and humm Kumbaya three times to yourself and hop around in a circle 3 times on one foot- but we have a pretty good idea, so I'm not going to waste a couple billion or even million dollars finding out. Mars will be an incredibly dangerous place to live- but not because of the gravity. The atmosphere (or rather, lack thereof) is by far the greatest danger. Habitats depressurizing, starvation, dehydration and freezing are what will kill colonists, not (likely minor) health complications from 0.38 g. It's a lot cheaper to find out what minor, probably treatable long-term health effects 0.38 g will lead to (I've told you emphatically already, basic, normal bodily functions will work just fine in 0.38 g) in the course of a mission that will *already* involve building a base with medical facilities and doctors, that you were going to carry out *anyways*, than to delay the ITS or carry out a study at current launch-prices... (thank you very much ULA for ripping us off for all these years on getting things to LEO) Regards, Northstar Edited October 25, 2016 by Northstar1989 Link to comment Share on other sites More sharing options...
kerbiloid Posted October 25, 2016 Share Posted October 25, 2016 (edited) 1 hour ago, Northstar1989 said: Sure, we don't know for sure what will happen to the colonists' bodies in 0.38 g. That doen't matter very much from the colony pov. Much more important is what will happen with baby growth. Presumably, nothing good. And of course, nobody will try this neither on LEO, nor on the Moon. (Unless cyberpunk takes over.) Edited October 25, 2016 by kerbiloid Link to comment Share on other sites More sharing options...
Nibb31 Posted October 25, 2016 Share Posted October 25, 2016 1 hour ago, Northstar1989 said: It's a lot cheaper to find out what minor, probably treatable long-term health effects 0.38 g will lead to (I've told you emphatically already, basic, normal bodily functions will work just fine in 0.38 g) in the course of a mission that will *already* involve building a base with medical facilities and doctors, that you were going to carry out *anyways*, than to delay the ITS or carry out a study at current launch-prices... (thank you very much ULA for ripping us off for all these years on getting things to LEO) I admire your certainty. Especially from someone who claims to have a scientific background. What you have is a hypothesis. Without experimentation, it has no more value than an opinion. We simply don't know what the effects of a martian environment on biological functions are, and we won't know until we go through that exploration phase with people living on mars in a temporary outpost. Any talk about colonization is just premature wishful thinking until we actually demonstrate that we can live and work there and that our assumptions are correct. There is A LOT of research and engineering to be done before we get to the level of confidence that is needed to send families for permanent settlement, and nobody seems to be interested in investing in that development work. It goes against all scientific method to claim the contrary. Link to comment Share on other sites More sharing options...
Nefrums Posted October 25, 2016 Share Posted October 25, 2016 (edited) 2 hours ago, Northstar1989 said: Haha, you must think you're very clever. You're not. Everybody dies eventually, but there is zero reason to think that Mars gravity will have anything to do with it. Just because something is unknown or new doesn't make it dangerous, and the human body is incredibly resilient- capable of surviving a lot more than you think. Of course I'm very clever, how else can I have unfounded opinions about something on the internet? But you misunderstand, I don't presume to have any idea of what low gravity will have for long term health effects. I'm just pointing out that as you say space is dangerous and death is a likely outcome, but that that will not mater to the people who will want to go. 23 minutes ago, Nibb31 said: There is A LOT of research and engineering to be done before we get to the level of confidence that is needed to send families for permanent settlement, And what level of confidence is that? And why would "we" need it? We are all used to living in a very safe world. This have not always been so and will not always be so. We have no right to tell other people what risks are acceptable for them. Risks will be huge and people will want to go anyway. Edited October 25, 2016 by Nefrums Link to comment Share on other sites More sharing options...
Tullius Posted October 25, 2016 Share Posted October 25, 2016 (edited) 1 hour ago, Nefrums said: ... And what level of confidence is that? And why would "we" need it? We are all used to living in a very safe world. This have not always been so and will not always be so. We have no right to tell other people what risks are acceptable for them. Risks will be huge and people will want to go anyway. Just because you find real life Jebediahs that still want to go on a mission to Mars despite you telling them that half of them won't survive, doesn't mean the risk is acceptable. Explaining to the public that the first human to put a foot on Mars is dead and that the guy waving so nicely on the photo close to the flag can't participate in the parade, because he is currently in hospital, would be very hard. However, I want to stress out that to prove that the ITS or any other spacecraft is safe for an expedition to Mars is rather simple: Just put it with a crew for 1.5 years into lunar orbit or very high Earth orbit, if everything works fine, you can send the next one to Mars, if not, you can return the crew within a few days. Edited October 25, 2016 by Tullius Link to comment Share on other sites More sharing options...
kunok Posted October 25, 2016 Share Posted October 25, 2016 If only we had a minor body close to earth, relatively easy and fast to reach with low gravity, like some natural satellite Colonization without doing any biological research is absurd, if only for the huge cost of making the first settlement in mars, to then discover that (for example) humans body develops illness at an exponential rate in low or no gravity, an effect that we still didn't see because it gets perceptible when you goes 2 years in low gravity. We only have full data of 1g, and a little (the longest stay in space was Valeri Polyakov, 437 days in the MIR) in 0g. Nothing in between, nothing at longer times Link to comment Share on other sites More sharing options...
Nibb31 Posted October 25, 2016 Share Posted October 25, 2016 (edited) 3 hours ago, Nefrums said: And what level of confidence is that? And why would "we" need it? NASA defines technology maturity with the TRL scale. TRL 8 or 9 means that you can use it for vital purposes on manned flights. Anything lower simply doesn't provide enough confidence. Quote We are all used to living in a very safe world. This have not always been so and will not always be so. We have no right to tell other people what risks are acceptable for them. Actually we do. As you say, we do not live in the same world as the generations before us. Legal, ethical, political, and PR constraints are just as important today as the economical and technical ones. You can't handwave them away. Unless you are drinking Musk's KoolAid, until there is a large sustainable settlement and a fleet of ships and thousands of people going back and forth, people won't be buying tickets and going on their own dime. For the first decades of exploration, the people who will go to Mars will be selected and sent by corporations and government institutions. As such, they will be under the responsibility of those organisations, so it is the duty of those organisations to ensure that they do everything they can to keep them healthy. The PR and legal backlash of losing people because you didn't do the proper research is simply too much of a risk and could actually jeopardize the whole effort. That's the world we live in, now. Quote Risks will be huge and people will want to go anyway. People aren't the ones investing billions of dollars here. If anyone does, it's going to be corporations or governments. When people start landing on Mars, they will do so as employees, not as private citizens. Edited October 25, 2016 by Nibb31 Link to comment Share on other sites More sharing options...
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