New Mars Forums

I think the problem is the ovalbumin. That's why frozen, say, egg beaters, don't taste so hot... weird mouthfeel? It's the LONG complexes of albumin that got denatured by the freezing temperatures. Never quite comes back. As far as transplantation... or testing of freezing... I can check with my graduate advisor since he's done cell culture related stuff.

Wow. That sounds terribly technical. "cell culture stuff"... *facepalm*

But anyhow, timeline wise it should be possible to freeze the embryo... I'm just not sure how you'd implant it into another egg unless you genetically modified a hen to lay eggs with zippers on them.

o.O

The embryo will be about a quarter to half the size of a grain of normal white rice by the time the egg is laid. I don't think that in itself poses problems. Just access through a rigid shell, which Mother Nature failed to provide with an emergency induction port.

As soon as these chickens are laying, I will attempt a test... I do not have a rooster, so I may see about testing it with a friend's eggs... might be crossing his rooster with my hens next spring, since Americauna/Barred-Rock crosses lay OLIVE GREEN eggs. I mean seriously, how can I resist? CAMO! lol...

Louis: the proto-chicken is ~24-30 hours old, since chickens tend to lay eggs about the same time every day. They don't, however, always lay one egg per day. It's essentially a daily menstrual cycle.

Der Germans can supply the CNC machines to cut all the parts that the other guys design. :-D

Adding a noncombustible means you're sapping thermal energy from the exhaust stream. Injected after the nozzle throat, it may help to cool the nozzle and add to total mass flow, as water injection was used to increase mass flow rates on jet engines back in the 60's and 70's before high-bypass turbofans were developed.

Carbon black is added to solid rocket fuel to alter the burn rate and enhance combustion stability, as are a few other inert compounds, but you'll find these in concentrations well under the 1-2% mark by mass. Carbon black can make an otherwise infrared-transparent fuel grain opaque, so the whole thing doesn't soften, melt, and splort out the nozzle before it's supposed to be burned. Other modifiers keep the fuel grain from simply detonating as surface area increases and pressures go up in a core-burning grain, and there are other plasticisers that aren't the best for "fuel" that can keep the grain from cracking or aid in thermal gradient management. Keep in mind the color of the exhaust plume on the SRB's, too - damn near white.

IIRC, though, your sweat would freeze solid at some point, sealing your pores, or the suit... basically boiling until it froze... the fabric suit keeps your skin from exploding and rupturing blood vessels, but as the liquid sweat is able to wick through the fabric, it would evaporate until it froze solid... and then slowly sublimate... would this be quick enough to carry heat away? I'm thinking a couple of peltiers and a wee bit of insulation would be a halfway decent idea. a pound or two of peltier junctions and battery should be able to tweak a heat balance issue on the hottest/coolest excursions - maybe just two, plastered right to your lower back over the kidneys, or right under the arms for maximum heat transfer to/from the bloodstream.

I would agree, though, that given the non-michelin-man form factor, you wouldn't need the liquid cooled undergarment currently used on EVA suits.

So a mechanical counterpressure suit, and body armor that you strap on over top?

Seems like you could make a relatively flimsy pressure suit, and just wear overgarments to prevent damage to the suit. Perhaps slip a wetsuit on directly over the mechanical pressure suit, which may add nominally to the effective pressure of the suit, and have velcro all over the wetsuit bit, to which kevlar gloves and sleeves and torso protection garments could be attached. Or you just put on a pair of slightly oversized normal work boots (oversized to accommodate the wetsuit and pressure suit thickness), and wear a long sleeved shirt, jeans, gloves, and a parka, with an oversized hood to fit your helmet?

I raise chickens, currently. Woot.

Here's a thought... Chicken eggs are full of water, essentially. If that's all you're transporting, then why not do a relatively small rocket with a few dozen eggs (the chickens will be laying six months after hatching, so as long as you have six months, you're OK...) and go for a continuous-thrust, high-power ion thruster... the payload would be measurable in kilograms, and with a 1g acceleration, and turning around halfway to Mars, you could have the whole package in Mars orbit in 72 hours... but i don't know of any thrusters that could do that... without ridiculous levels of power... i think the best ion thrusters now are about .02 lbs of thrust on 2000+ watts...

Has anyone run the numbers?

We have only three weeks... 60 million  kilometers... but WAIT! we have a slight time advantage... it takes 21 days for an egg to hatch, once it's brought up to incubation temperature... so we can kill the freezer at just shy of 3 weeks, and we have another 3 weeks before the little buggers start popping out... and the chill time will give us an extra buffer, since chilled eggs tend to hatch slightly later than under-chicken-butt eggs... and all we have to do is spin the module with the eggs in it and we've got something close to Mars gravity with little or no effort... so let's run the math and see what kind of acceleration we need to get there in 6 weeks with a negligible payload... and have chickens hatching (hopefully) soon after touchdown... unless we had a little space station in orbit around mars that could capture them and feed them, and then drop them to the surface along with the next crew... hmm... but that's later... let's see what kind of acceleration we'd need.

Let's just go with Newton on this one, and linear kinematics (just assume a straight line shot to Mars near closest approach) even though we'll be doing a rather more curved path in reality, we'll get an order-of-magnitude number:

3,628,800 seconds in 6 weeks...

if we're doing a turn-around-halfway-there approach, that's 1,814,400 seconds...

Overestimate to 7e7 km... half would be 3.5e7 km

If we assume we're in LEO, then launching our eggs from about 200km, that's roughly 7km/s initial velocity...

and we're solving for acceleration, so for the first half of the trip,

s=Vt+.5at^2 becomes...

(s-Vt)/.5t^2=a

[(3.5e10m)-(7e3m/s)(1.8e6)]/[.5((1.8e6)^2)]= .0076

.0076m/s^2

someone please check my math?

Assuming a 500kg of non-payload junk, and a 20kg payload of two dozen chicken eggs and the rack to hold/rock them, and we only use vehicle spin for a modicum of "gravity"... this would be a whopping 4 newtons of thrust for three weeks, followed by another 4 newtons of thrust for three weeks, then aerocapture from our original ~7km/s that we didn't bleed off in the second three week thrust phase...

Maybe we'd need more spacecraft mass just to make 4 newtons worth of ion thrust for the payload, but this is a startlingly low acceleration... seems like it might be slightly feasible. Or just barely not.

thoughts?

This thread:

http://newmars.com/forums/viewtopic.php?id=6052

made me think...

Why not try for an artificial magnetosphere on the Moon, to limit charged particle interactions with the surface/habs/inhabitants? With a significantly smaller radius, and with the benefit of Earth nearby, it may be possible to generate a pretty decent magnetic field with orders-of-magnitude less cable, and WAY cheaper launch costs... and then we'd have a working model to tool around with. The LHC seems like a pretty decent equivalent budget target...

Thoughts?

Hmm.

Ok, first, Nitrogen. We BATHE in it here. I think we'll need a bit more than trace amounts for a successful nitrogen cycle on Mars. Just my thoughts. Or, as mentioned, acclimatization or genetic engineering to handle the different gas ratios. Who knows, maybe some latent adaptation from early Earth will come to bear in the otherwise silent genetic code of terrestrial plants when transported to the new environment.

I'll poke around the other thread on buffer gases before I prattle on about Nitrogen again, thanks for the link.

As far as the core temperature, I have two chief points to address. I'm making this quick, as I've been outside mending a fence for my chickens, and I'm terribly hot and uncomfortable, so please don't take a short/terse post as any sort of argumentative tone, I'm simply sticking to my chair at the moment, and that may color my responses. Ick.

So, the first point is the cooling time of a planet from formation. I am on a slow connection, but IIRC, Lord Kelvin calculated the age of the earth to be somewhere in the 5-10,000 year range, based on the surface area to volume ratio of Earth (at that time known fairly well) and he was, from what I recall, within an order of magnitude on all his calculations. So let's be terribly generous and call it 100,000 years. Earth's core should have cooled and solidified a billion years ago, then, if there is no process heating things up inside.

Nonradioisotopic mechanisms available are tidal heating, magnetospheric interaction with the Sun, and impactors. either way, it's been more than 100,000 years since the last impact large enough to liquefy any significant fraction of the planet, and all three of these processes would affect Earth's orbit. The Moon seems a possible candidate for the tidal option, which would not alter Earth's orbit appreciably, but would have circularized and tidally-locked the Moon. Oh wait. The moon is tidally-locked.

Did that happen more than 100,000 years ago? I think, quite likely, it did.

So we are left with, as far as I know, either a magically self-sustaining magnetic dynamo, which would violate conservation of energy (since Earth's orbit isn't perpetually decaying toward the Sun at an appreciable rate) or, radioisotopes in the core/mantle.

I'm not sure why one would assume that the core had no radioisotopes in it. These isotopes are all heavier than, and generally soluble in, liquid iron. We need not have a significant loading of radioisotopes to add heat to the system and keep it molten, but it must be present. I tend to think even if they were all segregated somehow to the mantle, then you might just have enough to melt the outer core and keep it fluid. Just barely.

Now, this brings us to the thermal gradient. As we drill down in the earth, past the first few feet of soil, the temperature of the Earth increases at a few tens of degrees per thousand or so feet, as I believe was posted earlier.

Think of it this way, we have what amounts to a light bulb, providing relatively constant illumination to a sphere of material of known transparency. As the thickness of the sphere is increased, the illumination at the surface of the sphere falls off with the inverse square of the radius of the sphere. By the time you reach the surface, the temperature differential between, say, 100 feet down, and 1000 feet down, isn't terribly high. Tens of degrees. The heat flowing out of the body is spread out over a rapidly increasing surface area as you get away from the core, or even the mantle. This temperature gradient is exactly what you'd expect to see if there were something hot in the center of a body, radiating outward, just as the light bulb. The heat gets "dimmer" as you move outward, since the total heat input is the same, give or take, for each increment we examine, but the surface area explodes as the square of the radius. We're a couple of thousand miles from the core, standing here on the surface. Think of a bonfire. Stand next to it and you're likely to singe your eyebrows. Stand 100 feet away, and you're likely to barely feel its warmth. Wrap it in concrete, and the difference is even more substantial.

Think then, as well, of a furnace in a home. My oil furnace burns at a couple of thousand degrees, yet the outer shell rarely gets over 80 degrees farenheit. Admittedly there's a bit of a cooling system involved, carrying hot water to the rest of my house, but the thermal mass concept is the same - even with the circulation pump shut off, the inside surface of the furnace may be upwards of 600 degrees farenheit, but the outer surface will never exceed 80 or 90 degrees. Why? Because the fire box is only about a foot by a foot square by a foot and a half deep. The outside of the furnace is a full 5 feet long, three feet wide, and four feet tall. (Yes, this is ridiculously large, my house was built in 1957, but that's beside the point)

So all the heat of the core has to leave through the surface. If a planet is light, and not terribly dense, as Mars is, and we can assume it had some sort of geological activity in the past, then one must ask, where did it go? I posit that simply it was on a knife-edge, in terms of equilibrium. It got just enough radioactive elements to keep it hot for just long enough, and either we've witnessed the end of its geologic age due to radioactive depletion, or it's got round about as much hot rock as it had prior to a cataclysm, but it has lost just enough insulation to let it freeze up, its heat rejection outstripping its heat generation by some factor sufficient to cool it in the time since the cataclysm until now, or at least a few hundred thousand to a few million years ago, based on crater evidence @ Olympus Mons, etc.

So the atmosphere can in fact provide a substantial insulation for a molten core tucked away thousands of miles deep. The sun, or any surface activity really, won't have much effect on the core temperature - you're not going to shine a flashlight on an aluminum can and melt it any time soon - but a small heat source, properly insulated, can last a very, very, very long time.

Also, keep in mind that the subsurface temperature within 10-12 feet of the surface of Earth stays at a relatively constant 55-60 degrees in most places. Our average air temperature is slightly higher.

I am a blacksmith in my spare time, and I should also mention that, a properly insulated knife blade, or really any piece of metal I'm annealing, can go into my bucket of perlite or dry kitty litter glowing orange-hot, and many many hours later, still be hot enough to burn you, while the outside of the container isn't even warm to the touch. Direct physical contact, but decent insulation results in a very slow cooling time. I've thought for a long time about mounting a hot metal rod in a thermos bottle and seeing how long it takes to cool down from ~2000 degrees, what with the vacuum insulation and vapor-deposited aluminum mirror surface keeping things toasty.

The question is, what's the cool down time, and what's the actual rate at which heat from the core leaves the surface, and what energy input is needed. Then we can see if the possible radioisotopes dropped on Mars are sufficient to sustain this requisite energy output without undergoing an actual chain reaction, and then see how close we are when we factor in the insulating blanket of a nice, warm atmosphere. I dare say that if the numbers come up close, then we must assume that Mars had a dense atmosphere in the past, and its loss is what drove the core freezing event.

If it is not even close, on the short side, then we can assume that Olympus Mons and its siblings were catastrophic volcanic events resulting from a somewhat molten core and a large impact event, leading to a short-term melt/volcanism event.

But, that's just what I've come up with after some back-of-the-envelope calculations. Anyone wishing to chip in and do some of these calculations and beat me to it, feel free. I'm curious to know how far off my own estimates are.

I have done some back of the envelope calculations on this very topic recently, and I will post merely the results - if anyone's interested in seeing the actual calculations, I don't mind scanning and posting an image of my notes at some point.

In any case, I assumed the worst - a single loop of "wire" - the most malleable/ductile superconductor we have currently is niobium-tin, or in some cases niobium-tin-copper compositions. Assuming this is a single large cable to be unspooled in orbit around Mars, "spun up" as an MRI machine's magnet is powered up, and the whole thing encased in a fairly thin, thermally insulating conduit, and provided with a solar shield around its periphery, this should be able to maintain a low orbit at roughly 200-250Km.

I chose this altitude, versus geostationary, since we want to use the lowest current possible to generate a magnetic field, and the least amount of material possible. Further, the rotational motion of the coil relative to the spin of the planet may add a bit to the effective current, if only a negligible fraction.

My calculations left me somewhat disappointed: For an Earth-equivalent field of roughly 70 gauss, a one-meter diameter niobium-tin alloy superconducting cable, assumed to be solid for purposes of calculation, cooled with liquid helium, would be sufficient, but would require roughly 100% of our annual worldwide niobium mine output for a period of roughly a century, and nearly 10 years worth of Tin production. Taking into account mines that are planned or currently under construction, this could be reduced to roughly 65-70 years. The cost is astronomical, just for materials.

On the bright side, this technique is aided by the damn-near absolute-zero of outer space, so the portion of the cable eclipsed by the planet's shadow should provide enough cooling to allow something as simple as peltier junctions mounted every few meters to counteract any solar irradiation incurred beyond what a properly-spaced reflector could not handle on the day side. Since the whole cable would ride through the shadow every 90 minutes or so, and the solar shield/reflector could be composed of solar panels, the feasibility, if not the initial cost, becomes evident.

Further, the calculations assume that there is absolutely no planet in the middle of the coil. Since Mars has quite a bit of iron through its surface, mantle, and core, presumably, this would become a ferromagnetic core, increasing the field strength. Also, I neglected any plasmadynamic effects. If the field were caused to oscillate, or even held steady, but allowed to gather energy as an electric guitar pickup does, from the moving, time-varying plasma current, one could assume that the power for the coil could be had on-site, and only a minimal current required for start-up, with the current building in opposition to the solar wind, so long as seasonal variations were somewhat sizeable. Depending on the effective permeability of the planet as a magnetic core, the entire thing might well be scaled down by an order of magnitude or two. Further, with vastly superior deflection of electrons than protons, an electron-rich solar wind would allow the induced electric field to do most of the work. Another concept I failed to explore further, mathematically, would call for a non-single-loop coil geometry. Multiple turns wouldn't get you very far, but a helical or interlaced loop geometry could enhance local field strengths such that the aforementioned plasmadynamic effects could yeild a higher electric field strength, and thus better shielding. In any case, any shielding effected would be better than nothing, and the atmosphere should build.

Please consider this one key fact that is often overlooked: Mars' atmosphere is in a state of dynamic stability - it is continually losing atmospheric gas to nonthermal loss mechanisms, yet its atmosphere continues to remain at a stable, if low, pressure and density. If we inhibit even a small fraction of the loss, the atmosphere would build. If on the other hand, we build the atmosphere, we will be losing, perhaps the same percentage, but much more of the atmosphere. We'll be driving the reaction towards loss by adding gas to a lossy system. If we instead reduce loss mechanisms, the gases will add themselves, from whatever surface or subsurface sources are already in operation (anyone notice the detection of subsurface Methane sources not too long ago?). I'll have to look up the effective velocities, and calculate turning angles required for various orbits, perhaps writing up a system of equations and optimizing them for minimum material required (low loop current vs. shorter cable). It may very well be that a geostationary ring would require vastly lower current to achieve an adequate turning angle of maximum solar wind velocity, since it is further from the planet, or it could be that we would be better off with a larger diameter cable much lower in orbit, permitting a larger field but with considerably less cable length to encircle the planet at a lower altitude.

Either way, i would point out that any solution with a multitude of orbital components that are not physically connected, will be subject to magnetic attraction, or at least torques, which would require continual energy input to overcome. I think a single loop, or some variation on this Dyson-like ring is a better bet, since the loop would auto-inflate to a nearly perfect circle under the influence of its own magnetic field, much like a loop of string floating on a soap bubble. Individual magnets would pull together, and multitudes of loops would at the very least rotate to become a toroidal magnetic field, and the gaps between the loops would actually cause a degree of focusing.

It has also occurred to me that a slightly weak magnetic field might result in protection near the tropics, but deposition of solar wind components near the poles - thus heating the poles somewhat, but also adding hydrogen and helium to the atmosphere. Admtitedly, these would boil off rather quickly, but there should be enough radical production that water vapor would be created, and gravitationally retained within the atmosphere... I am uncertain as to the equilibrium state with high incidence angles for stellar wind particles on the atmosphere, if they would eject atmospheric particles more, or if they would be captured at a greater rate than the loss mechanisms... it's an interesting mathematical problem.

Ok, looks like I overshot the website debut by about 3 years...

I will be posting back soon, but Just wanted to touch base. Have had some major health setbacks in the family, almost losing my mother three times since my last posts on this forum. (by way of cancer and thromboembolism)

Will catch up soon
Rion

ah yes, i forgot that a sailboat can tack because the otherwise reverse thrust from the oncoming wind is able to be turned into propulsion because of the force exerted on the keel. I'm sure, however, that there is a way to achieve something similar so that a dirigible can at least go cross-wind, or at a slight upwind angle. On earth of course, there is so much air through which the craft must navigate, that the drag would easily overcome the thrust of any engine the craft could carry, to the point where it might as well be an airplane or helicopter. On mars however, i am not sure this is the case, though the cross sectional area of the craft would be immense compared to one on earth, since to achieve equal buoyancy one needs greater volume. This might wind up giving you roughly the same drag force with the higher wind speeds and lower density of the martian atmosphere. It's still worth checking out, since a dirigible could be anchored during high wind and simply released once the wind died down. It is a highly valuable option if properly executed, since an aircraft may well be heavier if not larger than a semirigid blimp/diridgible type craft. Deflated, it should be able to fit into a container not much bigger than two 55 gallon drums, not counting any crew compartment or engine, yet it should be able to 1-2 tons. An aircraft would more likely weigh upwards of 75% the weight of its cargo.

well i'm utterly exhausted and it's only noon... not exactly up for an hour and a half drive to Richmond this afternoon, but what are friends for... UGH!

take it easy guys, and keep the ideas coming

yes, of course it's your body temperature that matters... However, I did think about the plants. If you wore a pressure suit, and used martian atmosphere for the greenhouse atmospehere since plants eat CO2 for lunch (literally) you'd THEN have to worry about the ambient temperature. The plants would of course have to keep from freezing, but if you got them too warm, and the pressure was significantly reduced, you would wind up with exploding/freeze dried plants, since the fluids in their tissues would boil off. If you use a pressure suit then, your temperature and pressure worries are not over by a long shot. I don't really see the problem with working in a pressure suit, I've done quite a bit of work with bees and gardening using heavy gloves, since I grow blackberries, and I decided to use my beekeeper's gloves to do some harvesting and trimming of some plants, and It's quite easy to work with carrots and the like, especially in a hydroponic environment.

You can select plants with large fruiting bodies for greenhouse population on mars, such as carrots, large radishes, broadleaf lettuce and cabbage (for those with intestinal fortitude and a predisposition against gassyness...) and various other greens. Things like broccoli are easily cut with a sharp knife, and are large enough to not be a problem with bulky gloves. All sorts of choices can be made to accomodate a pressure suit in the greenhouse, but it'd be neater than sliced bread to walk around in shirtsleeves tending a garden and look down and see martian soil under your feet, and look through clear plastic at olympus mons rising in the distance.

as far as constructing the greenhouse, I think burying the whole structure except the very top is a fairly good idea, since you then reduce the strain on the entire structure to be local to the roof. The rest of the structure can translate the stress of inflation pressure to reinforced bands that line the greenhouse structure, and the roof is the only part that would bear that significant weight of 2 tons per square meter. If the rest of the greenhouse can be made of polyethylene, i don't see why you can't have a large flat or curved roof of interlocking polycarbonate panels which could be pre-prepped with a thin strip of cold set epoxy on a dovetail joint, and then when the whole thing is landed and unfolded for inflation, you simply peel off a piece of film on each tongue and groove or dovetail joint and slide them together, and the pressure of inflation forces the panels together, mixing and setting the epoxy. might be a lil complex, but i'm not sure how else to get around the vast stress that high pressure environments induce on the inside of the thin greenhouse structure.

Take care all,
Rion