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Well, some drugs are difficult to make, and some are not. There is more to "medicine" than drugs, too.
Decades ago, in high school chemistry, I (and all my classmates) made aspirin in the lab. It really was aspirin, but was not pure enough to use: it would give you a headache instead of curing one. But, there's a lot of older drugs that could be made with only a little better facilities than my old high school chemistry lab.
Most of the routine medicine needed will likely be treatment of injuries: cuts, abrasions, burns, broken bones. and similar. I really don't see treatment like that as being "too difficult" to achieve by occupants of a base on Mars. They'll need supplies shipped from Earth like bandages, sutures, plaster for casts, etc. But the skill to use them lies merely in a medical school education and post-schooling training.
If memory serves, the "blueberries" that produced such a stir when first found turned out to be iron oxide nodules. Something similar to limonite, at 65-70% iron by mass, I believe it was. Limonite is hand-crushable with simple tools. All you need to mine it off the surface is something like a front end loader to scoop up the surface material, in a bucket with a built-in sieve to let the sand drop through.
Then you need a reduction method to remove the oxygen from the iron oxide (chemistry helps reduce the direct thermal energy input, you'll need hydrogen for this). Then you need a source of carbon (not carbon dioxide, real carbon, here even coal and charcoal isn't pure enough, it takes a material called coke) to turn iron into steel.
To do all of this requires a lot of energy. Here on Earth we use things like Bessemer converters for this, but they "presume" an atmosphere with lots of oxygen, which burns with fuel to release the heat you need. We'll need to use a different direct reduction process on Mars. A more chemical one. I don't know what it is, though. Doesn't matter, you really don't want to do this (however you do it) inside a pressurized structure full of oxygen. Take a look at any steel mill in operation to see why. This has got to happen outside in a cold, super-thin (next to vacuum) CO2 atmosphere.
GW
Mid course with spin gravity:
You de-spin for every maneuver, then re-spin. Could be thrusters, could be inertia wheels. But you can NOT do this easily (or even with difficulty) with a cable-connected rig. It needs to be a "rigid" structure.
Which way do you spin?
If you spin around the long axis of a typical shape, the radius of your ship would have to be 56 m to provide 1 gee at the outer fiber, at 4 rpm, which is just about the max credible for long-term exposure. That way lies "Battlestar Galactica" problems. But, if you build it as a long, slender baton, the end-over-end mode is not only the most practical way to achieve a 56+ m "radius", it is also the most stable spin mode (the one with maximum mass moment of inertia).
How do we build such a thing without having to build a "Battlestar Galactica"?
Build it from modules docked together, with quick-disconnect plumbing and wiring connections. More or less like we built the ISS, but with a lot of the exact same modules (the propellant tanks). Both end-to-end and lateral connections, so you can reconfigure as a slenderer baton of the same length after each empty tank stage-off.
So why is cable-connected "bad"?
It is very difficult to spin up / spin down a "loosey-goosey" cable rig. Plus, one meteor hit on the cable cuts the cable, leaving you "dead" when your spinning vehicle comes apart while spinning, separating crew hab from propulsion. It is easy to spin-up / spin-down rigid structures, and meteor hit is just a leak to plug, not a complete vehicle loss.
GW
I'm very suspicious of a mission design that does not include artificial gravity. It's 6 to 8.5 months one-way to Mars, something OK with exercise on the ISS, if you accept loss of muscle tone. And maybe the other effects. We know it's recoverable in one case (only) of exposure to about 400 days.
It's roughly a year at Mars waiting for the orbits to be right for your return. And there is not one shred of direct (note that I said "direct") evidence to suggest that 0.38 gee is enough to be therapeutic. The assumed therapeutic effects of 0.38 gee seem to be the unspoken assumption in most of these mission plans. And, it is an assumption, nothing more.
Then it's another 6 to 8.5 months in zero gee home.
Roughly 2.5 years total at reduced-to-zero gravity. And what awaits you at journey's end? High-speed/high gee reentry.
It's several gees (3-6) from LEO if you recover them in orbit (1-4 gee burn by the way). If it's a free return, you hit the atmosphere at 50,000 feet/sec (about 17 km/s). Coming back from the moon at 2/3 that speed was an 11 gee proposition.
So, here's a crew with almost no strength and muscle tone left, significantly (or even seriously) weakened and embrittled bones, and possibly with vision and immune systems compromised, suffering high (or even really high) gees to come home. (Not to mention radiation sickness.) Trouble is, it won't kill them outright. They will most likely be crippled for the rest of their lives by this.
Why not just do the spin gravity? (And do the radiation shielding with the water and wastewater you already know will be going with them.) Does not ethical behavior demand it?
GW
Living on Mars will be much like living at South Pole Station, for a very long time, except it will be worse: nobody at South Pole Station needs a pressure suit, needs a radiation shield, or runs the risk of low-gravity-induced diseases.
At South Pole Station, we have a science base supported from the rest of civilization, for over half a century now. They have workshops and repair capabilities, and even some self-administered medical care, but all of this is based on supporting parts and materials shipped in every Antarctic summer. There is no infrastructure to support self-sufficiency at South Pole Station, nor is there likely to be any, for many decades yet.
We have already seen the limits of existing medicine without supporting medical infrastructure at South Pole Station, with two critically-ill persons having to be rescued in weather not normally considered flyable with jet fuel and hydraulic fluids. I know what kind of airplane could fly at -120 F to South Pole Station in winter, but that's a different discussion, for a different forum.
The same is going to be true at any base or settlement established on Mars. You can ship in supplies and materials from Earth roughly once every 2 Earth years, but the infrastructure to support self-sufficiency is just not going to be there for decades. Although, I find supporting infrastructure development on Mars more likely than at South Pole Station, because of human motivation. There is motivation to become self-sufficient on Mars, there likely will be no such motivation at South Pole Station, ever.
The medical care thing will likely be the first driver toward self-sufficiency on Mars. This is simply because of the impossibility of mounting rescue missions that far from Earth, not until something like a "Star Trek warp drive" gets invented. That is just one of the reasons a base on Mars is different from the base we have at South Pole Station. I think that kind of travel technology is still a very long way away. Centuries. Plural. Unlike flying to South Pole Station at -120 F.
As far as supporting infrastructure technology goes, regarding Mars, very little of what we do here will transport directly to Mars "as is". That is because the environmental and atmospheric conditions are so different there than here. You will not make steel the same way there that you do here. Same for aluminum. Same for copper. Same for plastics. Same for rocket propellants. Same for glass. Nothing we do here "fits right" in a cold, thin, CO2 atmosphere. And, just what the hell do we use for concrete? Some applications might substitute "icecrete", most cannot.
That's what the initial Mars base (or bases) is really for: to find the answers to those infrastructure technology questions. To find the answers to food production. To find the answers to water production. To find the answers to radiation protection. Etc.
Most of our preconceived ideas will prove to be wrong, I predict. Because they always have, for millennia, here. Where it's not so challenging. Not so different.
GW
Hi Glandu:
No such thing as an "illiterate Frenchman". The original language of science was French, about 2 centuries ago. A lot of folks seem to have forgotten that.
All:
Making plastics on Mars will require inherently different chemical engineering processes than here, simply because both the resources, and the environment, are so different. But, it must be done. Period. Not being a Chem-E, I cannot contribute much to that discussion.
I will say this: plastics are very unlikely to be on Mars the throwaway material that they are here on Earth. Steel will more likely be closer to that throwaway material, simply because there is a lot of iron in surface rocks on Mars, than there is organic material. Yet, even steel will be made differently there, and for exactly the same reasons as I cited for plastics.
Because it is (currently) so hostile there on Mars. I personally rather doubt that anything will be a "throwaway" material there. That's my hunch. No reasons to back that up, other than engineering intuition.
GW
Hi Louis:
There are some interesting ideas listed here. My 2 cents' worth: perhaps the best export would be intellectual property, because it can be sent electronically between planets, and at the speed of light.
I'm personally suspicious of staying in the mode of thinking "resource extraction" too long, and there are a lot of variations on that basic theme to be wary of. It is the thing most folks think of first, when establishing settlements "anywhere-not-here", and has been for centuries. Hard habit to resist.
Yet many of the modern countries (not all but the majority) that were colonies in the 16th century Spanish empire are 3rd world today. Spain stayed too long in the resource-extraction mode of thinking too long. Same for France: look at Quebec and especially Haiti today.
One has to be careful about unforeseen implications of whatever one does, though. For what is now the USA, the 3-way trade economy that replaced simple resource extraction was slaves-molasses-resources (mostly timber and raw crops). That caused vast social problems that are still with us today, but it did lead to colony prosperity generally, by the end of the 17th century.
GW
Well, in most of our countries, nuclear things are government monopolies. What that means, is that if the government really wants it, the anti-nuclear activists will not be able to stop it. Example: nuclear weapons.
That the anti-nuclear activists werre able to kill the thing tells me USAF was just dabbling with NTR during Star Wars, not so very serious. For one thing, the rockets we had were (even then) far more than adequate to hurl big warheads, without any nuclear stages. The overkill factor was on the thousands. What's the point of more?
That being said, I surely would like to see us working on a path toward a water-"fueled" gas core NTR, starting (of course) with something solid-core like Timberwind. That would be the 2-decade path anticipating those needs (exploration, small experimental bases, etc.). I think the nuclear explosion option ought to be seriously looked at, too, as the most practical for the giant ships needed for real colonization. That would be closer to a 5-decade path anticipating that need.
GW
Hi Robert:
When you say Timberwind 250 was "developed" by USAF, do you mean something actually built and tested in some way? If so, where did they test this thing? The old Jackass Flats facility in Nevada was already in serious disrepair by then. I remember talk of NTR being revived ca. 1980-ish, to counter an effort thought to be an NTR in Russia. Back then, the talk said this was CIA, but USAF would be the more experienced bunch. That Russian effort was thought by various groups to be any of several things, but did turn out to be some NTR work, similar (I think) to the old Project Rover NERVA stuff.
Myself, if we do bring back solid core NTR, I wish we would upgrade it to a water working fluid, as in the original 1950-vintage concept. There's an Isp penalty, to be sure, but the working fluid is available as ice in many locations throughout the solar system, including Mars. Melt it, gravitationally settle-out the solids, and run the cleaned water through the engine. Very easy to process with minimal equipment. Your "fuel tank" needs a door through which to load the ice, and a tap from which to draw off the separated solids.
If this can be made to work solid core, then it can likely be made to work in gas core, when that technology is ready to fly.
GW
Interesting stuff, this MITEE thing. I doubt that team exists anymore. These small business set-asides rarely (if ever) lead to anything mainstream significant. Unfortunately.
The PUR 12.pdf file has a nuclear ramjet variant. The Marquardt engine they used as a baseline shape is old indeed, there are far better ramjet components and designs now, and have been since the 1970's. And, in addition to the old Project Rover nuclear rocket engines that got tested in Nevada long ago, there was also a Project Pluto nuclear ramjet that also got tested in Nevada long ago.
The nuclear rocket got shut down by 1974, at the ready-to-flight test stage. Little has been done since then except paper studies and a couple of brief "resurrections" done by a couple of spy agencies. If that work had been continued, the remaining problems NERVA had would have been fixed by now, and we might even have gas core technology by now. After all, NERVA took place approximately half a century ago. I remember it in the news back then.
The nuclear ramjet in old "Rover" was far less successful. It had serious problems with a lethally-radioactive exhaust, and a lethally-strong trailing shock wave flying Mach 3 at a few hundred feet altitude. It was abandoned when they figured out these two effects would have killed more people than the thermonuclear bomb it was to push to target (the thing was to be a strategic cruise missile, before there ever were any ICBM's).
We first had working LOX-LH2 engines in the 1960's. The only new thing added since then is electric propulsion, but without any solutions to its idiotically-low thrust weight problems. Kerolox we have had since the 50's. There just hasn't been that much fruitful propulsion technology in recent decades, other than incremental improvements on what we have had for a long time.
Breakthroughs in propulsion are now long overdue. Undeveloped concepts would be fertile ground for those breakthroughs. Nuclear thermal offers one of those. So would nuclear pulse (explosion) propulsion. So would a lightweight energy source for electric propulsion.
GW
It's my understanding from what I have seen and read, that these localized magnetic fields are remnant fields frozen into isolated structures in the crust, left over from a time long ago when Mars had a strong global field. I'm guessing there is no longer any fluid overturn to power the iron core dynamo. May also explain the lack of tectonic plate activity. It all froze solid long ago.
GW
Latest internet news releases as of 2-14-2014 indicate NASA has decided the "jelly doughnut rock" was kicked-loose from some larger rock, and then kicked into the field of view, by one of the wheels on the rover. Given the shape of the thing, I think that unlikely, but that's just an unsupported gut feel on my part.
Same set of news releases indicated us and the Russians were the only countries spending over $10B per year on space. And yet the Chinese are launching manned missions to space stations on under $10B per year, while at the same time planting rovers on the moon. There are quite apparently some efficient-use-of-funds issues here.
GW
Mimic a rubber tire with thin aluminum? In the rocks? You have to be kidding me!
No one ever built a successful wheel like that here. Never. Not ever.
I think these labs should be talking to some real, dirty-fingernails engineers like me and a bunch of others I could name. They certainly don't seem to have anyone like that on their staffs.
GW
Hi Midoshi:
I guess I just don't understand what is so hard about drilling to 3 meters. Seems like that is the thing to do, so as not to be restricted about sites.
I have a friend in the soil sampling business for the civil engineering crowd. He drills past 3 m all the time, rocks or not. It just ain't that hard.
Maybe some of these science labs and crowds ought to be talking to some real, dirty-fingernails engineers, like him and me. Their staffs certainly seem to lack people like that, or MSL/Curiosity would not have the tire damage that it does.
GW
GW
Landing 100+ ton vehicles on Mars is not that big a deal from an engineering standpoint, if you use supersonic/hypersonic retro-propulsion. Period. Chutes are useless with ballistic coefficients that high.
The ONLY issue is exactly how to implement retro-propulsion. It has been studied before, just not very seriously, by NASA itself, ca. 1960. We do know from those test then that vehicle drag is reduced by the presence of a retro plume, in an amount dependent upon the massflow of that retro plume. A very simple wind tunnel test at Mach 2 told us that long ago.
The only real issue is retro plume(s) stability, because a plume that flip-flops from one side to the other as it reverses, may very well induce large destabilizing forces on the vehicle.
But, if you use multiple engines, and cant them off centerline, the retro plumes are pre-oriented toward one side. That should provide a stable flow field. The only question is how much cant is enough, and what variables does that depend upon?
That basic answer is determinable from supersonic to low hypersonic wind tunnel tests in very sub scale, with a 6-d.o.f. force balance holding your model. That is quite inexpensive to do: well under $1M at multiple universities with aero engineering departments, and their wind tunnels.
From there, it goes to subscale model tests high in our atmosphere on sounding rockets or via the suborbital spaceplane operators. All very cheap to do.
Then you build a full scale prototype, and launch it into the thin air with existing launchers.
Land one of those unmanned on Mars for final checkout. Program total should be under $50M, or somebody is stealing the money.
Then use it: land some men on Mars, for cryin' out loud!
GW
Hi Midoshi:
Do you have a feel for how deep these core samples will be extracted?
GW
About the only other issue is fiber elongation capability. My information may have been superseded in recent years, but 20+ years ago, carbon fiber had low elongation, making brittle failure of structures made with it a serious liability. It was popular in organic composites because of its high modulus of elasticity, which led to stiffer structures. It was/is popular in carbon-carbon composites because of its far higher usage temperatures.
Both applications suffered from the low elongation/brittle failure problem. Seems like I remember elongation-at-failure being 1-2% for carbon, 2-3% for kevlar, and 6+% for nylon. Those figures had direct impact on the shock-load behavior of tow lines made with the stuff. It also affects the radius of a fold made with the cloth. Too sharp a radius, and you fracture the fibers in the cloth. This shows up in the size of the cardboard tube the cloth comes rolled upon, and in the radii of structures you can make with it.
Woven-fabric porosity as a chute (or heat shield?) is not a killer problem. Although you have to deal with it. Finer weave reduces direct flow-through porosity. This is a compromise issue in supersonic parachutes. The ringsail is a variant on the older ribbon chute. Each panel is low porosity, but there have to be mahjor flowing gaps for aero stability in that application. Most of those are kevlar to take some heat, at the cost of serious opening-shock risks of destruction. If heat is not an issue, nylon is the better choice, being far less susceptible to opening shock damage.
I would think a fabric heat application would be similar in many ways to the supersonic parachute. You can design-out opening shock by deploying before start of entry, but the aero-stability of an extended lightweight and flexible surface like that may well require gaps, similar to a supersonic chute. In the heat shield application, gaps will let very high-energy plasma through, although at reduced Mach and somewhat limited quantity. Heat-sinking effects will be very important to survive that sort of thing. Using the old rule of thumb, you will have to deal with 5000 K (effective) gas at the start of a 5 km/s entry at Mars, and about 2000-3000 K at 2-3 km/s where peak heating occurs. Fortunately, the W/sq.cm are far lower at Mars than here.
GW
Quaoar: "On-Orbit Repair and Assembly Facility" is posted 2-11-14 over at "exrocketman" now.
Re: heat shield cloth materials. Carbon fiber will go fairly easily to 4000 F, maybe 4500 F. Not so sure about 5000 F. Somewhere it sublimates, and that temperature is lower at lower pressures. I used carbon successfully as monolithic graphite at 4000 F and hundreds of atm pressure differences in solid rocket motors. As a carbon matrix / carbon fiber composite, Shuttle used it at about 4000 F in the nose cap and leading edge pieces. It is quite brittle and fragile in that composite form (ref Shuttle Columbia loss from LE damage). If you don't use it as a composite, be aware that it is quite leaky porous in most weaves.
Re: aerobraking at Mars. As long as you can handle factor-2 variability in aerobraking force achievable at any given speed and altitude, then this will work fine. If you cannot handle factor-2 variability, then I would advise not betting lives upon it until you know that you can handle that kind of variability. That variability directly affects deceleration achievable, and less directly, point of landing by exponential change effects.
GW
Fish are covered in mucus. They live in water. Just like the ice-covered lakes we were discussing here.
GW
I have never advocated riding anywhere more than a week away in a space capsule. Any space capsule. Orion is no more suitable for a Mars mission than Dragon is. Or Gemini. Capsule is not equal to habitat. Not even close. NASA's Transhab design is also inadequate for Mars missions. It just takes more than that.
GW
There's things robots can do, and there's things men do better. That will always be true. We'll need capability for both. Remote manipulators, too.
I agree that airlocking is very wasteful of breathing gas residuals no matter how good your pump. That's why I think working in vacuum in a truly supple suit is the far better option. This will never happen if we stick with these "do-everything-in-one-garment" balloon suits we have now.
The MCP suit should be approached as vacuum-protective underwear plus an O2 helmet. You wear whatever conventional (!!!!!) protective clothing over it, that suits the job. Working inside the lighted spaceframe that I suggest, you need none. That suit inside there would very much resemble Webb's elastic spacesuit experimental rig of 1969-1972.
Inside, that's all you need. Pull on some white insulated coveralls, and maybe slip-over white insulated boots and gloves, when going out in the sun or shade. You could even come up with a broad-brimmed hat to fit the O2 helmet.
Once you adopt the vacuum-protective MCP underwear approach, all of this becomes easy. Not at all like now, and that threatens the semi-monopoly of the 2-3 suit makers we have. That's probably why none of them ever looked at this. Just Webb and now MIT, all at pittance funding.
Workpiece temperature control by lights inside a spaceframe covered in aluminized tarps is something very easy to do right now (we got a little start on Skylab 1 decades ago, but never went further). There's no real excuse not to try this out ASAP at ISS. Along with some experimental MCP suits.
If NASA or ESA won't try some of these techniques, I'd bet Bigelow and Spacex will, once they get to flying their own men. It's only a question of how long we have to wait before somebody does this, and makes fools of the rest.
GW
Tom:
What's wrong is us screwing up: hitting Earth instead of LEO. Hitting Earth is a lot harder to do if you aim out near the moon. Much later, with experience, asteroids to LEO for mining becomes reliable enough to be safe.
This kind of thing will be limited to very small asteroids for several decades to come. The bigger ones are the more interesting ones with the most volatiles. Those are out in the main belt.
Any ship good enough to take men to Mars could visit the main belt, especially with some hotter propulsion fitted to it.
The very best targets are way out there, and mostly too large to divert. That's why I think diverting very small asteroids to Earth vicinity is a side path off to the side of the road we really should be traveling.
GW
Nextel 440 is very similar to the Nextel 300-series I have used. It's an aluminosilicate, with phase change embrittlement and cracking at about 2300 F, and a meltpoint pretty close to 3200 F. It's square-woven of yarns, close weave, but still porous. It's very much like fiberglass boat cloth, when you handle it.
Up to a point, you can handle stagnation heating at Mars, even in the essentially "white" color. But maybe not for direct entry from interplanetary transfer, that's getting to be too fast, the re-radiating surface temperatures are getting very high. Once you heat it and cool it, that's when the embrittlement and shrinkage cracking occur. For one shot use only, you might tolerate stagnation zone material surface temperatures between the 2300 and 3200 F limits.
The properties and usage limitations are very similar to my ceramic composite heat shield. All the alumino-silicate materials have essentially the same characteristics at high temperatures. I have some curves on this posted over at "exrocketman". They should be a good ballpark guide.
As for Dragon's heat shield, it wasn't originally designed for a free return from the moon, it was designed for a free return from Mars. That's much tougher, being around 17 km/s at entry. It's also why they could fly the same capsule back from LEO unrefurbished 4+ times if they want to. And they probably will.
The Orion guys sneer at it to deflect the knowledge that Dragon is more capable in many ways, just smaller, and therefore much easier to launch. 7 crew in Dragon would be about as cramped as Gemini was. 2 weeks was too much for Borman and Lovell on Gemini 7.
GW
The ice-covered lake idea I posted over at "exrocketman" was just one of two ways to grow food, not really a habitat all by itself.
There's food that grows in water, for which an ice-covered lake would be an ideal way to have stable water on Mars without massive construction of pressurized structures. This offers more growing space on Mars with less effort than any other thing I could think of. I do not believe there is a fundamental scaling limit on this approach: these lakes could be as big as anyone could ever want. That was "Aquaculture Habitat Lake for Mars" dated 3-18-12. The main thing you need to build one is the equivalent to a bulldozer.
The other is food grown in air, which requires pressurized structures. The easiest I could think of was a mushroom-shaped structure with a transparency around the perimeter under the mushroom cap. That's also posted over at "exrocketman" as "Aboveground Mars Houses" dated 1-26-13. That approach is limited by scaling of structures vs material strengths, unlike the ice-covered lake. These would require the equivalent of front end loaders and bulldozers to construct, and we would need an equivalent to earthly concrete, plus transparency panels probably brought from Earth.
GW
Frontal drag will always be an insoluble problem for supersonic/hypersonic blimp ideas, no matter what kind of rocket you try to push it with.
GW
Quaoar:
I've a start on that idea posted already on "exrocketman". There's "End of an Era Need Not Be End of a Capability" dated 8-2-11. It deals with having shuttle bay-and-arm capability as a permanently-orbiting facility, to which the sunshade space frame and lights could be very easily added. Adding that capability is only a little more ambitious than the sunshade parasol on Skylab 1 decades ago.
And there's "Fundamental Design Criteria for Alternative Spacesuit Approaches" 1-21-11. This one analyzes partial pressures in breathing gases relative to centuries of human experiences, for compression criteria applicable to new spacesuit designs. I got the same answers that Dr. Webb got for his "elastic spacesuit" of 1969-1972.
A shirtsleeve pressurized hangar is a much more ambitious undertaking. Given a supple spacesuit, you don't need it. In an unpressurized sunshade enclosure, with work piece temperature controlled by the power of the lighting, your gloves need not be thermally insulated, they can be quite thin compression garments indeed.
Plus, with an MCP suit composed of sections, experience indicates you could doff the gloves and work barehanded in vacuum for up to about 30 minutes, before any edema and swelling sets in. Just recompress with gloves or go inside before the time is up. Barehanded, very fine work indeed becomes possible.
Yep, you're right. I need to post this idea as a fleshed-out design concept.
GW