I believe that the Chinese can do it; but do the Ameriacns have the will to do it? Opinions
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I believe that the Chinese can do it; but do the Ameriacns have the will to do it? Opinions
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Depends on which Americans you ask. :wink:
Order of Kilopi
IF the Chinese would go manned to Mars (in 20 years) and if they continue to change their political/economical system in the current direction, I don't see why this should give the US a kick to make their own manned Mars program.
The times where spaceflight was also a vehicle to proof some political point seem to be long gone.
Harald
Order of Kilopi
Remember fellows: chemical rockets won´t take us anywhere. Be content with the electronic eyes and arms of our probes. Wait until there is significant tech. The Moon is all the Chinese (and the rest of us) can afford.
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Well, I don't know. That does seem like a counsel of despair to me. After all the most important issue of all is the cost of delivering a kg of payload to Earth orbit. It has not been shown that large cost reductions here cannot be achieved using chemical rockets (perhaps air-breathing, true). And, as Heinlein noted, once you're there, you're halfway to everywhere [in the Solar System, anyway].Originally Posted by Argos
The real issues seem to be institutional and political. I would doubt that NASA, under its current dispensation anyway, is capable of pursuing Cheap Access to Space to fruition. Probably the OSP will be just another X-33/Venturestar fiasco. But it needn't be so.
Which are fantastic, but it is not unreasonable to be impatient about the state of manned spaceflight, particularly given the wastage of billions on a space station that cannot perform any useful science - a fraction of which funds could probably be used to lower the current costs of space launches and improve reliability (too late, really - I know). At least we'll get a European ATV out of the programme, though - might come in handy in the future.
You mean wait for someone to build a beanstalk?
Fine - it's plenty to be going on with - get the infrastructure sorted and you can use lunar materials to go further. I'm all for a Moon First approach (perhaps with a few NEOs thrown in).
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Why? Antarctica, or even Wyoming provide far more Mars-like environments than anything Luna could provide, and at far less expense. Mars has an atmosphere, and a nearly 24-hour day. The Moon has no atmosphere and a 672 hour day. While Earth's gravity is about 2.5 times that of Mars, Mars's gravity is 2.5 times that of the Moon. In addition, the types of science you would do on Mars resemble the science which you would do on Earth far more closely than the scientific research able to be carried out on Luna. The Moon has no value as a training base for Mars missions. NEOs have even less.
While it is possible to mine oxygen from lunar rocks for rocket propellant or electrolyze water from the lunar poles to get propellant, it does not help for Mars flights to refuel at Luna. Even if infinite quantities of rocket fuel were sitting on the lunar surface right now - and they aren't - it would be, at best, ridculously illogical to refuel a Mars-bound spacecraft at the Moon. Why? Because before you can refuel at the Moon, you have to get there. Getting from the surface of the Earth to the surface of the Moon actually requires more Delta-V than going from the surface of Earth to the surface of Mars. So, from a propulsive point of view, it is much easier to send a spacecraft directly to Mars than to send it to the Moon first. Refueling your Mars craft at the Moon is like having a flight from London to New York stop over in Moscow for refueling. It just makes no sense.
If one small (Prometheus-class) nuclear reactor is available, a complete human Mars mission becomes available with three Saturn V-class boosters. The book The Case for Mars fully explains this in full, but I will summarize the main concepts of the Mars Direct plan here.
First, a Saturn-V class booster launches a 40-tonne unmanned payload to the surface of Mars on a 258-day Hohmann transfer. This craft, called the Earth Return Vehicle, or ERV, lands at the future landing site of the human Mars mission. It is an unfueled methane/oxygen propellant two stage ascent and Earth return vehicle. It lands with a 100 kWe nuclear reactor, a light truck, a set of compressors, and a chemical processing unit. The truck is telerobotically driven a few hundred meters away, and it deploys the nuclear reactor which will power the chemical processing unit. Six tonnes of hydrogen are brought from Earth, and it is reacted with Martian carbon dioxide to produce methane and water. The water is electrolysed to provide oxygen, both as air for the crew and as propellant, and the hydrogen is recycled into the system. This produces 48 tonnes of methane and 24 tonnes of oxygen. Martian carbon dioxide is disassociated to provide 36 more tonnes of oxygen. 108 tonnes of methane/oxygen propellant is now available, as is nine tonnes of water. 96 tonnes of propellant will be used to fuel the ERV, and the remaining 12 tonnes are available for internal combustion engine rovers. Now, from one Saturn-V class booster, we have a fully fueled Earth Return Vehicle, complete with water and air, waiting for the crew on Mars, one which has survived a landing.
Twenty-six months later, in the next launch window, two more Saturn-V class boosters are sent towards Mars. One carries another ERV for the next landing site, and the other is a "Hab", the crew's vehicle. It carries a crew of four, an internal combustion pressurized rover, two light rovers, and 500 kilograms of scientific equipment (500 more are on the ERV, making for a total of one thousand kilograms of scientific equipment).
Provisions for three years are carried. After launch, a cable is extended between the Hab and the upper stage of the booster, providing artifical gravity. The total mass of the Hab is 28 tonnes and it can be sent on a 180-day trajectory.
This is an extremely safe plan. The crew has a rover with a one-way range of 1,000 kilometers if they do not land right next to the ERV. Even if they land on the other side of the planet, the second ERV can be targeted to land near it. Even if both of them miss, the crew has provisions for thee years and can just wait until another ERV can be sent out. The plant is extremely robust.
The crew stays on the surface for 1 1/2 years, and there is ebough rover fuel available for about 22,000 kilometers of traverses. Thus, each mission can explore about 800,000 square kilometers during their stay. The Mars Direct harware can be easily modified to accomplish lunar missions, also.
So, we have a complete Mars exploration mission with nothing more than three Saturn Vs, some chemical engineering that has been around for over a century, and some present-day technology. No fantastical schemes are required for a Mars mission. We can do this, now. So, in contrast to your statement, while chemical rockets are certainly nowhere near as good as nuclear rockets, they certainly are sufficient, at least initially. The time it would take to convince the public of the safety of NTRs is not worth postponing our first Mars missions for.
This is possibly the statement I disagree most strongly with. The limitations of Mars robotic exploration have to be placed in context. Robots are fine on Mars for photographic surveys, seismology, meterology, and limited geochemical science. But searching for fossils, let alone extant life, requires intelligence and versality of an entirely different type. Fossil hunting requires heavy work - to do it for real, digging trenches and hammering rocks is required. So is fine work- splitting layers of shale to look for life between layers. It also requires complex perception. Sojourner and Athena have no manipulative capablities. Athena cannot travel over 100 meters a day. Both types of rovers, indeed, most any type of robot would be stopped dead by a boulder field or slope that would easy for a five year old.
Rovers and robots of other types are no substitute for real live scientists. You could parachute thousands of MER-type rovers onto Earth, and it is a fair bet that they might not find any fossils, at least not before the arrival of the next ice age, when they would be crushed by the glaciers which they would not be able to outrun.
Looking for extant life has much greater demands. No robot that will available in the next fifty years will be able to find groundwater or do any serious subsurface studies of Mars, where the life or paast life is likely to be found. First, a spot must be chosen with radar. Then a drilling rig must be set up - and the complex operations required to set one up totally rule out the robots which will be available for at least the next 25 years. And even if a robot could do this, it is doubtful that it could then analyze the life and the context of where it was found. But a human can easily do all of these, and more. A trained geologist's eyes are orders of magnitude beyond what a rover could tell us. Take the Mini-TES instrument on MER. It tells us of the composition of rocks. Now, a trained geologist could operate such an instrument (of far more complexity, owing to the 500 kilogram margin for scientific equipment) and tell us exactly what it was we are looking at. No robot could do that, because robots cannot think. Geology done by robots, as well as biology, comes nowhere near the level achievable by humans. Could robots hike through a mountainous rocky area, set up complex instruments, describe what they are seeing, know how that landscape formed, and pick up and examine rocks? No. Could they pick up rocks of special interest? No. Could they distinguish important geological finds from unimportant ones? No. Robots cannot think; scientists can.
As a final example, take an Apollo mission, Apollo 15. The entire ALSEP would probably be too complex for modern robots to set up. Could these same robots than explore the region? It is doubtful that such finds as the Genesis rock or things like removing stuck drills from the surface could be done by robots. On Mars, humans will simply be so much better than robots that comparisons become useless. Even collecting samples and core samples on Mars (hundreds of pounds at least) would be far beyond the ability of robots. And could these robots also explore the region, take thousands of pictures, and generally perform all of the scientific functions that humans can?
In a word, no.
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BigJim--
I liked your description of Mars Direct -- but I wondered, has anyone thought out the psychological issues that a crew might have to deal with I know there is a tendency to think that any crew selected will be able to muddle on through. But I wonder if there are ways to deal with the pressure of living in a can for a year with the same four people. Or five, or even six. (The more the better, because larger groups allow to diffuse tensions, but still). I do not think this makes a mission impossible, by the way, but I know that if you can't step outside to cool off or even have a smoke break most people go nuts. Not in the strictly clinical sense, here, but you wouldn't want someone getting royally irritated at his shipmate and unceremoniuosly chucking him out the airlock because he left the toothpaste on the sink.
Kim Stanley Robinson's Red Mars discusses this issue, but he postulates a mission of 100 people.
I keep thinking of theproblems the people that live and work in Antarctica have run into (there are many accounts of this). Now, they are much less isolated than people on a Mars trip, there are more of them, and you can step outside for a minute on the spur of the moment and cool off (no pun intended) when there are problems. Has there been any rigoruos work on the issue? Have the Russians done any?
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Beautiful..:wink: Nice post Jim.
Project NERVA
NERVA diagram About same as above but more descriptive. Don't ask me where I got it from, looks like a scan, because I honestly don't remember (if you know where it is from please let me know). Save it to your computer for repeated viewing, please, Geocities is evil afterall.
Nuclear Power: The Future of Spaceflight?
Ever heard of the Gulag?Have the Russians done any?
Links brought to you by your friendly Alaskan nutcase. -Colt
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This is one of the issues with manned Mars flights that I have often seen mentioned but find somewhat frivolous. Let's examine the situation of a crew in the Mars Direct scheme. We have a crew of four in a habitat with an area of approximately 1,000 square feet, and each crewmember has a private room. They are essentially confined to this space for the six months of the outbound flight if recreational EVAs are not done. Once on Mars, the crew has available about double the space they previously had (because their supplies are unloaded upon landing) in the Hab, the ERV cabin, with about half the space, and the pressurized rover. They will also be making a huge number of surface explorations and be working a large fraction of the day. The return trip will have them confined to the ERV cabin which has about 500 square feet of room.
Now, let's compare this to the average state of a World War II GI, who could have been away for three or more years. The soldiers faced constant threat from enemy attack, bad food, low pay, cold, heat, mud, rain, lice, disease, and armies of men and machines doing everything in their power to kill them. The crew of a Mars mission will have good food, warm beds, and a reasonably comfortable overall existence. In addition, they have the tremendous psychological boost of knowing that they are worldwide heroes; once home, their fortunes are made. The crew of a Mars mission would be a select, close-knit group of scientists of engineers; I do not see why they would be likely or even have a small possibility of going insane. Cosmonauts have spent up to 18 months on Mir, a much more confined space without the opportunity for surface exploration of another planet, and kept their sanity. I see the human mind being one of the strongest parts of a Mars mission, and not something that would stop it.
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A manned mission to Mars would be easy.
All you'd have to do is collect 900 empty jars of Burma Shave™.
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I don't know if the GI comparision works -- as I said before, people in situations like that are surrounded by lots of other people. A better comparision might be the crew on a submarine -- which stays under for months at a time -- and manages to work together well. But that is in part because of a military culture and indoctrination process -- I mean there is a reason these guys all train for months together. I am not sure that model works for scientific missions, at least in its raw form.
I mean lets face it, air travel for 16 hours to Tokyo is boring enough. Gad, I do not know what I would do for six months in a similar-sized space, even if it is with only a few other people and there i lots of room. I mean, let's face it, those six months in transit are going to be boring as hell -- how many measurements of the interplanetary medium and observations can you make? Longer missions are even worse. (Though if you could rig up a strong reciever to pick up some TV that would help a lot). 1,000 square feet isn't that much by the way, (it's about the size of my apartment) but the prospect of getting more space in a forseeable future would mitigate that.
Again I stress that I don't think this is a sinker for a mission of any stripe. Nor do I think they will be reduced to drooling idiots or kill each other. I just think it's worth thinking about, especially when we talk about longer-duration trips, as some are inevitable. Again, I refer to Robinson's book -- he talks about the problem of double binds that such a mission puts you in. (You have to be focused enough to be excellent in your field to get picked, but such people tend to be really bad at working with others, for instance). I am not sure test-pilot types would be good for this, for example.
It sounds like the Russians would probably have the most and best experience for this kind of stuff, no? My favorite remark, perhaps apocryphal, was from a Russian cosmonaut who thought the ban on booze in space was ludicrous. Maybe they have the right idea.
Anyway, it was just a thought.
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As I've said, Mir cosmonauts have spent up to 18 months in space and remained psychologically healthy. Of course a Mars-bound craft would carry many experiments and a load of books, games, tapes and other entertainment material.
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You are probably right that the Moon wouldn't provide a similar enough environment to Mars that you couldn't get right here with some work. But, for an extended mission of 3 years or so, we would need space equipment that is much more robust than we have now. Just think of all the things that break on our current manned craft all the time. It would be too difficult to carry the tons of spare equipment needed, so the equipment on the Mars mission would need to last in the space environment and the Mars enviroment for years. By placing a mission on the Moon first, you can test the equipment for years in space, while the crew is only 3 days or so away from Earth if something goes wrong. The time spent at the test site on the Moon would be great for developing the equipment, procedures, experience, etc, nearby to Earth before taking the years long journey to Mars.Why? Antarctica, or even Wyoming provide far more Mars-like environments than anything Luna could provide, and at far less expense. Mars has an atmosphere, and a nearly 24-hour day. The Moon has no atmosphere and a 672 hour day. While Earth's gravity is about 2.5 times that of Mars, Mars's gravity is 2.5 times that of the Moon. In addition, the types of science you would do on Mars resemble the science which you would do on Earth far more closely than the scientific research able to be carried out on Luna. The Moon has no value as a training base for Mars missions. NEOs have even less.
While it is possible to mine oxygen from lunar rocks for rocket propellant or electrolyze water from the lunar poles to get propellant, it does not help for Mars flights to refuel at Luna. Even if infinite quantities of rocket fuel were sitting on the lunar surface right now - and they aren't - it would be, at best, ridculously illogical to refuel a Mars-bound spacecraft at the Moon. Why? Because before you can refuel at the Moon, you have to get there. Getting from the surface of the Earth to the surface of the Moon actually requires more Delta-V than going from the surface of Earth to the surface of Mars. So, from a propulsive point of view, it is much easier to send a spacecraft directly to Mars than to send it to the Moon first. Refueling your Mars craft at the Moon is like having a flight from London to New York stop over in Moscow for refueling. It just makes no sense.
Another concern I read about but hadn't thought of was medicine. The Apollo missions only lasted a few weeks at most, so illness wasn't too big a concern. But what happens to the Mars bound astronaut who develops appendicitis, or a fast acting cancer, or something else where you need a hospital? New medical equipment and maybe even procedures would need to be developed and tested.
Also, the psychological aspects of the mission can be tested while the mission is removed from Earth. Sure, you could set up a biosphere here on Earth and stuff people in it for 18 months, but the rest of the world is right outside the walls. If you run a mission on the Moon, not only do you have the problem of "I quit, open the door" solved by 250k miles of vacuum, but the increased tension of the deadly Moon environment just outside the walls. Mars isn't the Moon, but both are extremely deadly to humans.
So I think it shouldn't be 'only Mars' or 'only the Moon', but a plan using stations in orbit, test missions (and maybe a small base or two) on the Moon and then the long leap to Mars and beyond.
Kizarvexis
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I have two things to say about this statement. First, this is one of the reasons why manned craft are more reliable than their unmanned counterparts. There have been many equipment failures on spacecraft, most notably on Mir - but in all of them, humans have been able to repair the damage or maintain systems. The crew for a manned Mars mission undoubtedly would include one or two engineers, probably those who helped design the craft. There would be few problems that these engineers wouldn't be able to fix, and those that they couldn't fix would most likely not have derived solutions from lunar research. For example, a micrometeroid shattering a window and causing a depressurization would be deadly and dangerous, but I don't see what we could learn on the Moon about such a risk that we couldn't either plan ahead for or simply hope that it is too improbable to cause a serious risk. (e.g. In theory, the ISS could suddenly lose all its power due to a series of short circuits, but it is unlikely.)Just think of all the things that break on our current manned craft all the time. It would be too difficult to carry the tons of spare equipment needed, so the equipment on the Mars mission would need to last in the space environment and the Mars enviroment for years.
Second is the statement about needing to develop procedures and test equipment on the Moon. Again, this is my point. Luna is very unlike Mars. The lunar surface is a vacuum, with a 28-day light/dark cycle and one-sixth G, as well as comparatively large amounts of solar radiation. While Earth is certainly far more hospitable than Mars, Mars is far more hosptiable than the Moon. For one thing, equipment on the Moon is subject to far greater stress from temperature than equipment on Mars. On the Moon, equipment or spacecraft will be in constant sunlight and then constant darkness for up to two weeks, with temperatures ranging from 250 degrees above Fahrenheit to 250 degrees below. On Mars, there is a 24 hour 37 minute day, close to Earth's. The temperature averages around 67 degrees below Fahrenheit. While cold, this is nowhere near as cold as the Moon can get, and is comparable to Antarctica. I would say that testing equipment in Antarctica would be far more useful to Mars-craft designers than testing it on Luna. The temperatures in Antarctica and Mars are similar, as is the day-night cycle. The radiation influx and atmospheric conditions, while different on Mars and Earth, are more alike than those on Mars and Luna. I cannot think of many spacecraft systems that would benefit from testing on Luna more so than testing in Antarctica.
Besides the equipment, the scientific procedures would also probably be tested before a Mars mission. But again, the types of science you could do in Antarctica, Alaska, or even Wyoming or Montana are far closer to the types of science you would do on Mars than anything you would do on Luna. Mars had a similar early history to Earth. Both had water, thick atmoshperes, and (possibly) life. The geological and hydrological processes Mars has undergone FAR more closely resemble what Earth has experienced than what Luna has experienced. And, needless to say, searching for extant life or liquid water on the Moon is impossible.
Again, this is not something we would benefit from by spending large amounts of time on the Moon. What "new medical equipment and procedures" could be or would need to be developed on the Moon? We know how to treat simple illnesses such as the flu or a cold. I don't see what we could learn on the Moon about it. And how would we know whether astronauts would get sick on the Moon or on a Mars journey? It would be on a completely indivdualistic basis. Do we simply sit around on the Moon and wait for someone to get sick? Even if an astronaut did develop a dangerous disease such as a cancer on the Moon, what knowledge would we gain there that would help on a Mars mission? A fast acting cancer or similarly deadly disease would be unfortunate, but is one of the myriad risks you have to accept in any space exploration. Space exploration is dangerous, but the benefits made it infinitely valuable.Another concern I read about but hadn't thought of was medicine. The Apollo missions only lasted a few weeks at most, so illness wasn't too big a concern. But what happens to the Mars bound astronaut who develops appendicitis, or a fast acting cancer, or something else where you need a hospital? New medical equipment and maybe even procedures would need to be developed and tested.
And, once again, what would we be able to learn on Luna that would benefit this significantly? You are right. You can't just leave on Luna. Nor can you just leave on the Moon. But testing astronauts to see how long they stay sane simply makes no sense. To borrow a phrase from Robert Zubrin, to do that would be like training bomber pilots by having them fly through real flak. The risks of insanity are infintesimal. If it were to happen on the Moon or Mars, it would be terrible for the mission. But what could we learn on the Moon about long-term space stays that we could apply to Mars missions? The select crew of a Mars mission will be selected, among other reasons, for mental vigor. I don't see why they have to "go crazy" at some point in the mission. The cosmonauts of Mir, as I said, have spent up to 18 months there in good psychological health, and have not attempted to do anything that would be dangerous to their lives. "I quit, open the door" attitudes would not be what mission planners would look for in the first Mars crew. A highly motivated team of four scientists and engineers would not be likely to lost their sanity on a mission of science and exploration. Submarines are a decent example of isolation, but Mir showed that humans can and do endure up to eighteen months in space; and that was in zero-G with no opportunities for exploration of another world.Also, the psychological aspects of the mission can be tested while the mission is removed from Earth. Sure, you could set up a biosphere here on Earth and stuff people in it for 18 months, but the rest of the world is right outside the walls. If you run a mission on the Moon, not only do you have the problem of "I quit, open the door" solved by 250k miles of vacuum, but the increased tension of the deadly Moon environment just outside the walls.
I believe the two are spearate. The Moon is good for astronomy and mining helium-3 in the medium and long-term. But Mars offers an opportunity for a whole new branch of human civilization, with vast opportunities for science and for economical endeavors. Mars is a huge world, with practically unlimited possibilites for colonization, exploration, and science. The Moon does have a potential for colonies but not nearly anything of the caliber of what Mars offers, especially since the vast majority of the things needed to support life can be found on Mars; a Martian base could be self-sufficient.So I think it shouldn't be 'only Mars' or 'only the Moon', but a plan using stations in orbit, test missions (and maybe a small base or two) on the Moon and then the long leap to Mars and beyond.
So, while eventually we should colonize both the Moon and Mars, Mars is a vastly different world. Just because the Moon is closer does not mean that we have to spend many years there before voyaging to Mars. While we should expore both, they are separate worlds; it would not be beneficial to use the Moon as an "intermediate step" in a Mars program. It would be like using an ultralight aircraft to train for flying a jet; they are totally unrelated, even though they are both aircraft.
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It would be a case of refining procedures and equipment, rather than research. In the military, you train on how to maneuver under fire using empty weapons. Once sufficently trained, you go to a live fire range to try it against targets using live ammo. Using this analogy, testing on Earth would be the empty weapon training and a 1.5-3 year mission on the Moon would be the live fire excerise. To see if everything works together in the harsh environment of space and can survive the time involved in Mars mission. If it can survive the rigors of the Moon and testing on Earth, the Mars would be a piece of cake. (Remember, half of the Mars mission is travelling to and from there in the vacuum of space.)
Ok, auto-docs and medical expert systems could be tested here on the Earth just as well as on the Moon.
Same as for medicine.
Well you do learn to fly on a safer training plane and then graduate to the big planes. Yes, Mars and the Moon are two different environments, but both are extremely hazardous. Not to mention that Mars is soo much farther away than the Moon (timewise). I'm not saying that we would do the same exact things on the Moon that we would do on Mars, but it seems to me a matter of scale. Setting up a long term base on the Moon would be the equilvalent of learning to walk and travelling to Mars would be the equilvalent of learning to run. (Apollo was crawling.
Kizarvexis
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Um, am I missing somehting, or do I detect a certain bias in both BigJim and Kizarvexis towards their respective favorite vacation destinations? 8)
BigJim-- it makes sense to me that if the Moon is a tougher environment, that is a good place to test equipment, at least some of it. The environment you described sounds to me like one that I could say "Hey, if this thing works on the Moon, Mars is easy!"
Kizarvexis -- one of the differences with equipment on the Moon is that, for instance, vacuum-welding of moving parts is an issue where on Mars it isn't, at least not in the same way. (It is harder to make lubricants that work in a vacuum because they tend to sublimate, and that's just one example). So there are some things that are better tested in Antarctica. In fact, in Northern Canada there wre people testing out hab technology now. (Anyone know if that project is still active?)
To say that Mas offers possibilities to human culture and civilization that the Moon never will seems a bit -- well, unimaginative. (See Stephen Baxter, Space, for a nice treatment of potential life on the Moon).
Both worlds are worthy of colonization efforts on their merits.
Could the Mars Direct method be applied to other planets? Maybe a set of simultaneous flights? (I know that is a near-impossible dream, but one can hope).
Something about medical treatment, by the way-- you would expect a mission to have a doctor, and basic surgical equipment on board, no? Not enough for brain surgery, but enough to be like the mobile hospital units in the military or a trauma center.
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To say that Mars offers possibilities to human culture and civilization that the Moon never will seems a bit -- well, unimaginative.
I am not exactly saying that the Moon does not offer possibilities for colonization, but that Mars has far more so. Mars is a much easier world to live on and it is possible to be self-sufficient there. It is much larger, offers a huge range of terrain, and in the long run can be terraformed. The Moon can be colonized but lunar colonies would be more purely scientific (astronomy) or industrial (helium-3).
Yes. I would venture to say that most worlds probably are.Both worlds are worthy of colonization efforts on their merits.
Mars Direct was originally designed to satisfy the Mars and lunar requirements of SEI. While primarily structured for Mars missions, the basic architecture can also be used for long-term lunar missions. With lunar missions in mind, the ERV's propulsion was divided into two stages. Mars missions would use both, which would have the right amount of propellant to return a crew to Earth from Mars. The upper stage would have enough propellant to being a crew home from the Moon.Could the Mars Direct method be applied to other planets?
Since the lower stage is much larger than the upper stage, an Ares rocket (the preferred Saturn-V class launch vehicle of Mars Direct, based on STS technology) could be used to deliver a fully fueled ERV upper stage to Luna. A Hab could then be sent out to land near it. So, yes, Mars Direct hardware could also be used for long-term lunar exploration missions.
As far as I know, missions to other worlds have not been looked into, but I do not think the hardware could be used on other planets or moons. Venus, with its heat and crushing pressure, would need extremely robust and strong vehicles, beyond the engineering capabilities we have today (although on opposition class missions to Mars there is a Venus flyby, but that is different from a landing or orbital msision). Mercury would be hard to reach and has the same heat problems as Venus. I don't think that a Mars Direct style mission would be the ideal type for the outer planets, either. So, basically, Mars Direct is specialized for the Moon and Mars, although on both worlds it would be a tremendous mission for exploration, science, and discovery.
The author of the Mars Direct plan, Robert Zubrin, talks about this in his book, The Case for Mars. He expresses disagreement with this idea, and I agree with him. From his book (this quote may not be exact, it's from memory) :Something about medical treatment, by the way-- you would expect a mission to have a doctor, and basic surgical equipment on board, no? Not enough for brain surgery, but enough to be like the mobile hospital units in the military or a trauma center.
On a 2 1/2 year Mars flight, a dedicated doctor or surgeon who spends his time reading medical texts or being a pest by subjecting the crew to an in-depth medical study is cumbersome and unneeded. In the unlikely event that anyone gets sick, expert consultation from Earth and on-board systems should be able to treat most ailments (such as ear infections). One of the crew members could be cross-trained to a medic's level of knowledge or one of the crew could have been a doctor earlier in life. But most of the effects of long term zero-G exposure have already been documented on the Salyut stations, Mir, and the International Space Station, and we know an awful lot about it already - and the mission most likely will use artificial gravity on the outbound leg of the journey. A crewmember whose function is to essentially wait until someone requires surgery is a complete waste on a mission to another world when his place could be taken by a geologist, geochemist, engineer, or more scientific equipment. A mission to Mars should take only what is needed. As I've said, a serious medical condition would be unfortunate, but it is one of the risks you have to accept in space exploration. A Mars or lunar colony should certainly have a doctor, but a Mars Direct style mission should not. The majority of medical conditions could be handled by the crew or by doctors on Earth - there is no need for a dedicated doctor on board.
One has begun in Utah, and I think it replaces the one that was on Devon Island, but I'm not sure. Go here for more information.In fact, in Northern Canada there wre people testing out hab technology now. (Anyone know if that project is still active?)
I'm not sure. I still think it is like using a crossbow to learn how to use a rifle. They're both weapons, but they're dissimilar enough that you don't need to learn how to use one before the other. I don't think we'll agree on this anytime soon, but let me summarize my point: the majority of equipment for a Mars mission can be tested in an environment on Earth such as Antarctica. The equipment that has to work for approximately one year in a vacuum (on a conjunction class mission there is a six month inbound and outbound trip) does not have to be tested on the Moon - I think that our engineers have enough experience by now that they don't actually have to test it in a vacuum to see if it will work. ISS components aren't tested in a vacuum for extended periods of time - they are simply designed to work in a vacuum, and they do. So I think that good design and testing in Antarctica would be enough for the Mars Direct mission. [/quote]Using this analogy, testing on Earth would be the empty weapon training and a 1.5-3 year mission on the Moon would be the live fire excerise.
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I don't know that the conditions on the Moon are close enough to the conditions on Mars to justify lunar testing. Antarctica can be dangerous, and the Amazon can be dangerous, but it isn't really safe to say that if you can survive the rigors of one, you can survive the other.
Antarctica provides an easily accesible testing location similar to Mars, and we don't have to squander any expensive launches on setting up lunar training grounds. If you want a place to test the spacecraft in vacuum, we could launch a mission into a high Earth orbit. That way we have actual travel condition tests, and if there's a problem, then Earth isn't nearly so far away. Of course, you couldn't do the same science in Earth orbit that you'd do on the Moon, but if you're testing how the crew will react to several months in a confined space, you won't be letting them outside to explore anyway.
On the other hand, if (say) the US elected a President that was clearly dedicated to manned space exploration, the Moon might be an ideal starting-off point. A return to the Moon might be easier for Congress and the citizenry to swallow, and once we have the hardware to make it to the Moon, we could push farther and say "well, now that we have hardware to make it to the Moon, we have Mars within our reach. Let's go."
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Yep, you wouldn't necessarily test all equipment on a Moon mission, but I bet there is a lot you could test. And I just like the idea of walking before running.
Well, in the article I read, the missions that were discussed only had a few people, so no doctor would be expected to be along for the ride. So development of autodocs and the like was presented as a need for long term missions.
Kizarvexis
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OK, it's the late 1800's and you're planning an Antarctic expedition. Do you send your dogsled to the Sahara to practice? They're both deserts.
Similarities between the moon and Mars: lower atmospheric pressure than earth, colder at night than earth, lower surface gravity than earth.
Differences between the moon and Mars: Mars has an atmosphere, Mars has twice the surface gravity of the moon, lunar dust is incredibly abrasive, Mars has lower solar insolation, shorter day/night cycle.
A vehicle designed for Mars will likely not run on the moon. A cooling system designed for Mars will likely not work on the moon. An atmosphere plant designed for Mars will likely not work on the moon. An EVA suit designed for Mars may not work on the moon. Even a nuclear reactor designed for Mars may not run on the moon (it depends on how it is cooled).
One of the things you could test would be human reaction to lunar gravity. If humans exposed to three years of lunar gravity didn't suffer the deprivations that one year of microgravity causes, we could be reasonably sure that three years of Mars gravity would be ok. On the other hand, if long term exposure to lunar gravity is bad, it doesn't tell us much about long term exposure to Mars gravity.
Yep, you wouldn't necessarily test all equipment on a Moon mission, but I bet there is a lot you could test. And I just like the idea of walking before running.
I'd think if we were interested in Mars that a rotating space station would be a necessary first step--we could spin it up to .4 g and see what a few years does. That would probably be cheaper than a moon base.
I don't know if that is necessary or not. The Mars crew will be cross-trained in a variety of disciplines. Some of them will be medical. They won't be able to handle everything--dental, surgery up to appendicitis, maybe. Which means that someone who got sick enough on the mission might die, whereas if they'd stayed behind on earth they would have lived.
Well, in the article I read, the missions that were discussed only had a few people, so no doctor would be expected to be along for the ride. So development of autodocs and the like was presented as a need for long term missions.
Kizarvexis
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Vacuum welding? I think I know what you are talking about but not sure. An excellent book, IMO, to read would be Mars by Ben Bova about some of the challenges faced. Of course I haven't read it in quite some time so things are a bit foggy.
I'm with Jim on this issue. -Colt
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BigJim, have you seen Red Planet?
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I have. Why?
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Wasn't their idea slightly similar to what you've been suggesting. Setup up an automated outpost that will generate the goodies in time for the arrival of the crew.
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Not really. Their plan to get to Mars was extremely bloated, to say the least. They assembled a huge spacecraft on-orbit, which is unneccessary if Mars Direct is used and also reduces most quality control issues to zero compared to what you can do on Earth. And yet they land in a tiny spacecraft that has few capabilities. Their "hab" is extremely large and also appears to be very delicate, as it is destroyed. In Mars Direct, two more realistic spacecraft are involved, and I would venture to say they have far more potential for doing surface science. A lot of programs use pre-landed spacecraft but Red Planet is an example of one that is not realistic. Mission to Mars, while not a great movie from a science standpoint, actually had a fairly realistic-looking Mars landing site. The transfer ship.... was something else entirely. I don't really see why so many Mars mission plans have to have huge Mars transfer craft but small landing craft- the optimum mission is to have the entire crew land there. Apollo was different as it was shorter duration and one launch. But in long term missions you have zero-G and radiation coming into play, and on the surface of Mars you don't have to worry about zero-G and the radiation influx is less.
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No Burma Shave in Russiaops:
Moscow, February 22
"A Russian interplanetary shuttle can be built in five years...and 9-10 billion rubles...weighing 12-14 tonnes will have a reusable capsule for a six-men crew..."
http://makeashorterlink.com/?T24354E77
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(emphasis added)
Perhaps you've heard of the Columbia?
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With the obvious exception of catastrophic launch or return failures.
Jon
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Some early Mars missions had multiple vessels; this obviously adds redundancy and flexibility (as well as cost).
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I'm not sure about these ideas, there are questions to be answered on finance and other issues..it would be great however there are serious problems like safety and projects and other ideas that had years of neglect, but we will have to wait and see
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