MISSION LOG – SOL 45
Another long day of work, another day closer to planting crops. Today was all about turning soil, and all of us were doing that except for Starlight. She was doing this really clever thing with the ceiling crystals, cutting caps off of some of the bigger ones, slicing them into these neat spiky flower shapes, and turning them into some sort of sun relay. Spitfire took them topside and lined them up directly above the cave, and now the cave has light- a lot more light than I’d have expected. Starlight tried to explain- something about extra surface area of the flower-cut crystals- but Spitfire sent her back to the rover before she could finish.
The ponies have done a better job than I’d expected of breaking up the dense Martian soil in the cave. Of course, Starlight’s spell provided a head start, providing a lot of microscopic voids that loosened the dirt enough for our makeshift sled-harrow to get down into it. It also helped Fireball and me shovel out the channels for the ponies’ neat idea for attacking the heat problem in the cave.
On Earth, once you go beyond a certain level below the surface, it begins to get hotter. Our planet has a thin crust and a lot of internal heat. If Mars has any internal heat left, it’s hiding it very, very well. The cave is actually slightly colder than the surface. And since it’s mostly buried under rock, soil and permafrost, warming up the interior means battling one of the worst heat sinks of all time.
The pony solution? Steam heat.
Let me explain the logic. The pony ship mainly relied on their ship’s atmospheric exchange magic for cabin heating. There were only a few emergency space heaters in the ship, and when I tested them they turned out to be just as thirsty for electricity as expected. It’s like they just grabbed a space heater at a flea market or something and stuck it into their ship. Each one sucks up almost 200 watts of electricity. We’re going to use them anyway, because we need all the heat we can get down there.
I could yank the larger heaters from the rovers, but we need those to not freeze driving to and from the cave. Besides, just the little heaters will require eight solar panels from the Hab plus one of my hydrogen fuel cells to keep them running at night. More heaters like that will take the Hab below a safety margin I’m just not ready to exceed yet.
We have the pony ship’s air working again, and I’ve taken advantage of that at the Hab to shut down all the air systems and do a full diagnostic. (Everything checks out, by the way.) That means we can install the pony life support box in the cave and use it to fill it up with nice temperate pony air. Problem solved, right?
Well, not really. There’s hundreds of meters of geode cave beyond this first chamber that will be Fireball’s dinner for the next four years. Also, the roof of the chamber is several meters high at its highest point. The warm air will circulate back in the cave and up to the ceiling, and there’s dick we can do about that. That means the air will cool, sink, and circulate back to freeze the crops.
That’s entropy, folks- even when you get a free lunch, there ain’t no free lunch. All we can do is improvise a thermal blanket from pony ship insulation, hang it over the entrance to the next chamber, and hope for the best.
But in addition to providing air, the pony life support provides water- both cold and hot, because hot water is what the ponies use to reconstitute or heat up meals in flight. The ponies have kept the hot water deactivated because, up to now, all we’ve needed is cold water, and the hot water flow is about one-fifth that of the cold water.
Why is this, you ask? Because although the ship only had a few emergency heaters, it had a lot of cooling hoses and pipes. In space you don’t have air or water to equalize heat. You have one side of your ship baking in the sun (if you’re lucky enough to be near the sun) and the other side freezing in shadow. This heat differential is bad for equipment and can even endanger the crew, so there are ways to deal with it. Insulation works, and the old “barbecue roll” used by Apollo works just fine, but in this case the ponies went with a heat exchanger system tucked between the outer hull and the pressurized compartments- all provided with fluid from the ship’s cold water supply.
Water is definitely not the coolant NASA would have chosen. There are lots of chemicals which have a wider range of liquid states and a greater heat-exchange efficiency. But the ponies have all the water they want practically free and can replenish it in-flight if there’s a leak, and apparently they can’t do that with the other options. (Besides, I can’t help feeling like Dragonfly or Fireball might be tempted to drink the radiator fluid.)
As a result, there are dozens of meters of plumbing, all with fittings designed to fit the cold water terminal on the life control box. And today Dragonfly fitted them all together into long rows, and Fireball and I buried them all a couple feet into the soil. There’s one fitting sticking up at one end to hook to the life support box and another fitting that will have a valve. That’ll be left open to let water circulate through the system, and the outflow will be used to water crops or just allowed to trickle off downstream into the back of the cave.
The neat trick- and the ponies have already arranged for this with their folks back home- is that the cold water and hot water can be switched. All it takes is swapping two crystals back home. So instead of cold water suitable for redistributing heat under a spaceship’s skin, the pipes will be filled with literally boiling water at one end and will release barely-above-freezing water at the other end, if it works.
Net result: the cave will never be tropical, and we’ll probably wear our suits in here just for comfort- not a phrase you normally hear from an astronaut. But the actual ground where the plants will be rooted should be warm enough for them to live. And some of that subsurface heat will spread above the surface and add to what the air, the heaters, and Starlight’s magical sunlight system provide, and that in theory should protect the plants above ground.
The main problem with this system is that it seriously constrains the area we can cultivate. The chamber is twenty-one meters wide at its widest point and about one hundred ten meters from the inner airlock doors to the narrow bit at the back. Eyeballing it, it’s a bit less than half an acre. But the area covered by the improvised hydronic heat system is a lot smaller- an area of about sixteen meters wide by forty long, or six hundred forty square meters.
Granted, that is a huge improvement over the Hab. My math shows that, if the field is one-quarter potatoes and the rest alfalfa, the cave would be enough by itself for an almost indefinitely sustainable food supply. But there are problems, of course, the biggest being that almost three-quarters of the ground in the room will be sucking away heat from the remaining one-quarter. Ironically, this cave is too damn big.
But it’s what we have. The next chamber is a forest of shafts of crystal- there must have been a mineral spring in that chamber for a while before it merged with the others. Getting equipment through that into the next room would be a major pain- and so would getting harvests out again. And if something does go wrong with this cave, we really do want to be as close to the exit as possible.
Tomorrow we hook up the electrical systems and life support, turn it on, and leave. There’s going to be a huge wind when the air comes in, and we really don’t want to be around for that. After that we take a couple of days off to let our brilliant improvisation do whatever it’s going to do, and then- assuming nothing new explodes in our faces- we take the surplus cultured soil out there, mix it with the harrowed topsoil, and begin planting seeds.
Two days in the Hab suits me just fine. I’ve been burning through CO2 filters- curse you cheap idiot government contractors! Staying inside means I’m not using more filters.. Besides, my potato seed crop has sprouted, and I’d like to spend a bit of time giving my future food supply some TLC.
And maybe we can have a marathon TV day and consign the Partridge Family back to the Stygian depths of the 1970s whence they came, never to return. That’s one thing I honestly like about Dukes of Hazzard: no twee children. Seriously, if I want any more overwhelming cuteness, I’ll…
… yeah, who am I kidding? The alien commander is pink and has eyes half the size of her head. Even the insect-like horror has puppy-dog eyes (without pupils). I’m going to be the first human to contract diabetes on Mars.
I recall someone making a mirror complex like this to funnel sunlight into buildings so plants could be grown even in the centers. It was a neat concept, but expensive and impractical in an office building... and the mirrors tended to get damaged far too easily.
Hmm... might want to make use of the excess hot water they have by putting in a pond at the low end of the cave. A larger body of water will hold heat longer and release it more slowly. It's unfortunate they don't have large containers or they could do what I did for a while with my tiny 36 square foot greenhouse: fill cat litter buckets with hot water and stack them on top of each other. It kept the whole thing above freezing for two days, even during single digit nights. Ultimately, though, it was a pain to keep refilling the buckets. And with all the water in the cave, there's going to be the issue of immense amounts of condensation. There will be something like a steady cold rain from the crystals, eventually, as the ceiling slowly warms. Fortunately for them, the slanted floor means the farmed part near the top won't become over-saturated. Unfortunately, it also means they're going to have a growing lake down at the other end in time as they keep running hot water in to warm the cave. Maybe they'll need to connect some sort of waste-water disposal system into the next chamber with a valve to take advantage of the negative pressure on the other side.
This doesn't work. Conservation of energy says that you can't have a space heater be inefficient; the energy has to go somewhere, and heat is kind of the end of the line when it comes to conservation of energy. Well, it doesn't work without magic, anyways, and I can't imagine the ponies have heaters designed to lose their energy off to magic phenomena or something.
Also, I'm still holding out hope for the RTG.
And then you have Starlight, probably one of the most adorable ponies on the show.
You know, if Mars would like a new core, it could just eat Mercury, which is basically just an iron planet core with its outer layers stripped off after a collision at some point late in its formation (it is a very dense planet for its size). And it's still molten inside, enough that even the slightly not-quite-tidally-locked rotation and its orbital eccentricity is enough to induce a weak global magnetic field. Stick it inside Mars, with Mars' rotation, and voila! Internal dynamo and magnetic field!
Then it needs an atmosphere... smash Titan into it! Now you've got all your organics, water and nitrogen!
See how easy it is? All you need are some god powers; and that's, like, the easiest step of all, am I right?
Ouch, Kris just train-wrecked with that space heater power explanation. I've pointed out in PM why he just broke reality over his knee without realizing it.
Short version, he just violated the first law of thermodynamics.
Hmm. Well, quartz is certainly quite scratch-resistant, so the mirror array should be fine as long as they keep the dust off. I just hope the environmental systems handle the kludge work well. And that the whole thing doesn't blow up in everyone's collective faces, but that seems rather unlikely from a narrative standpoint. Not yet, anyway.
Did he expected heat pumps? There is no heat sources/heat sinks on a spaceship for them to work.
I wonder what area she needed to cover with these crystal flowers to provide necessary insolation for plants inside. Mars receives ~500W/m^2 (approx. half of Earth's level), so >1000m^2?
Starlight is pretty pink too.
8702797 I'd always been under the impression that some heaters were better than others, but doing the research, I see not. I'll change it.
8702838
“Heat energy cannot be created not destroyed”
I was extremely confused for most of the time you talked about the heating system because I was thinking "OK, so where does the steam come in?"
You don't need the home maintenance appendix in the back of the inspection report we paid for when we bought our house to know that hot-water heat systems and steam heat systems are not the same thing. A quick look at Wikipedia will do.
8702794
I believe, these days, the solution is to put silvered parabolic dishes on the roof which concentrate sunlight into fibre-optic lines, which are then routed to wherever you want light using standard LAN-fibre routing techniques and terminated with pseudo-lightbulb fixtures to diffuse the light again.
8702797
There are places for the energy to go other than heat or magic like light or radio waves. But you are correct that the energy can't just disappear and that when most of the time when you are talking about lost efficiency the lost energy is lost as heat.
The other thing that needs to be brought up is that resistive heaters are incredibly simple. Just a piece of something that has a higher restance than the wire connected to it. The only complexity is finding something that won't deteriorate over time. They would have had to go out of their way to make a "inefficient" heater.
8702838 Fixed it. I was under the impression that some resistors were better at converting electricity to heat than others. Research says differently in no uncertain terms.
8702867 Watney's from Chicago, so I presumed he'd use "steam heat" as a shorthand for any water-based heating system even if the water is never allowed to gassify.
Hopefully he'll think about the rtg for heating. It would help quite a bit.
It should be noted that earth (rocks, dirt, sand, etc.) Actually makes a pretty good heat spreader and insulator. Once they get the cave warmed up, it should stay that way fairly easilly. The hard part is getting it warmed to start with.
I'm also curious what NASA will make of a huge (by Mars standards) heat plume right next to the hab.
8702884
Nonetheless, it confused the hell out of at least one of the rest of us (me). Do you think it'd be in-character for him to have picked up the term "hydronics" in his training? (Whether you say "a hydronic system", "hydronic heating", etc., it's the general category of fluid-based heat systems that encompasses steam, water, glycol, mineral oil, or any other kind of fluid transfer medium.)
Aside from not being actively incorrect, it's jargon-y enough for the average reader to learn its meaning from context rather than jumping to an incorrect conclusion which then messes with the immersiveness if they let it confuse them.
Sunset is making a light collector, and Distributors using Prisms, much more efficient than mirrors.
As for the heating pool idea, Did the use all of the Plastic Hab tents for the Surface farm?
If not Open on of those up to use as a liner for a collection pool.
I don't know if someone's already asked this and I just missed it, but why does Fireball keep his strength while Cherry seems to have lost much of hers (at least that's the way she makes it sound)?
Is dragon strength just not based on magic somehow? Or is Cherry just losing her magic dealing with the soil and not recovering it quickly while Fireball isn't using his for anything?
In a related thought, I'm interested to see how Cherry's magic will affect the plants.
8702901 Watney almost certainly would have picked up the word hydronics. But he's deliberately writing the logs in layman's terms, on the assumption that whoever reads them, long after his death, won't necessarily be a scientist or engineer.
I don't know if you've read the original book or not, but the log entries are very thoroughly de-jargoned whenever possible.
8702867 It's still a rather inefficient and expensive way to grow basil indoors. And you'd better anchor that dish really well against wind.
On Mars, much less of an issue since the atmosphere is too thin for wind to do all that much more than blow dust around.
8702908 I think it's a mix of both. We've seen in the show that Spike can carry a large load, and we probably know that earth ponies can use magic to grow crops.
Fireball is just lifting things, while Cherry is lifting and magicing. She's somewhere in the middle of the Watney-Starlight physical to magical exhaustion scale.
8702926
True. I'd mostly heard of it being used in situations such as "a science museum wants to reduce lighting costs while also demonstrating the wonderous things technology can do".
Obviously, but these also aren't very big.
8702908 Dragons are a lot tougher than even earth ponies. And I'm going to leave it there for now.
8702907 I got the idea from something I saw on TV in the early 80s, where Japanese architects were developing light collectors that would use fiber-optics to channel actual sunlight from skyscraper roofs into windowless rooms in the interior of the building.
8702909
Seeing something as confusing as referring to steam heating when there was no steam involved led me to conclude that, rather than actively working to de-jargon his reports, he was just writing informally out of habit.
8702953
Unfortunately, canon is *extremely* erratic when it comes to abilities. What characters are capable of changes dramatically depending on what they need them to do in any given episode. So with things like this I always have to check with the author since there's such a huge range of possibilities of what the author can make a character capable of.
8702964 Yeah... I wish the show would go and clear up earth pony magic, or give us a scene that shows Spike is stronger than non-earth ponies.
I need consistency, damn it!
8702955
Seems legit. I was just curious since it seemed to be inconsistent, but if you have plans then I'll wait and see what you have in store.
8702966
Unfortunately, I doubt it'll ever happen. Despite how many adult viewers it has, the show is still targeted at children, and they don't tend to care about the little details quite so much, lol.
8702987 #gen5please
I dunno if anyone mentioned this from the last chapter...
...but wouldn't this be the basis for a solar-magical converter? They've got tons of crystal to convert into batteries, and a unicorn that can teleport; they might not need rescue from Earth, just a telescope so Starlight can aim.
8703001 A magic battery the size of Mars wouldn't be enough to power a single-jump teleport from Earth to the Moon. Otherwise the ponies wouldn't have bothered with conventional rockets at all.
As for the other option...
8702794
As i understand water is actually great insulator in addition of being cold-sink, and that would keep a lot of warmth from leaving the cave. It would also seal down bottom cracks which suck off air as the water would penetrate the cracks and freeze. And even if theoretically the lake would itself freeze then they could easily keep additional loop of "used warm water" being pumped on the ice and then off forcing there to be layer of water over the said pond.
Also even if it would fail and it would freeze, then you have cut down on surface area sucking warmth off from the cave itself, specially if you were to cover the said ice with Martian soil as secondary layer.
Edit:
And has the Dragons meal goes, i am sure he can hoard it before hand for short-term, dive as needed if it stays lake and dig down if it indeed becomes wholly frozen lake.
8703015
Okay a single jump might be impractical. They've got spacesuits, they could always stutterwarp their way across, maybe jerry-rig a rover so when NASA sees them coming it'll be like that scene from the beginning of Heavy Metal..?
8702878
The other commenters are right- a resistive heater has 100% electricity-> heat conversion. HOWEVER, if you define energy as power dissipated in resistor / power generated by source, then the internal resistance of the cables and inefficiencies in generator come into play. The most efficient you can get is if the resistance of the load is matched to the internal resistance of the source.
8703033
ARES Rover to ISS, ARES Rover to ISS, Coming in for a pit-stop. Gas, check the oil and don't forget the windshield cleaning.
mark watney first human to get diabeetus on mars
Keep up the great work!
8702955
Ahh, Victorean Light wells and Light chimneys. Or, all those small glass tiled sections you see in the oldest buildings around. Closed off so that electric light could be flogged instead.
Reminds me of the patent app I tried back in the 90s for a non image forming non linear optical concentrator array. Got the idea from combining two things, one of which was a UV sensor lens system. Supposedly it did something weird along the lines of frequency doubling.
8703092
I don't think that they could get past the Martian atmosphere, but that would be hilarious.
8702878
Not fully fixed, I'm afraid. You cannot have better "energy efficiency" when converting energy to heat. That's always going to be perfect, exactly 1:1, essentially. Preventing energy from being lost as heat is the hard part.
I think the best fix is for the Equestrian heaters to have low power, i.e. you cannot safely put much wattage through them without them melting. Maybe change the paragraph to:
Let me explain the logic. The pony ship mainly relied on their ship’s atmospheric exchange magic for cabin heating. There were only a few emergency space heaters in the ship, and when I tested them they turned out to be just as low powered as expected. It’s like they just grabbed a space heater at a flea market or something and stuck it into their ship. Each one can only take 200 watts of electricity without the internal fuse blowing or just plain melting. We’re going to use them anyway, because we need all the heat we can get down there.
Never seen the mars movie but i'll check out the story
8702856
It comes down to energy conversion, and the number of conversions. You feed electricity into a fan motor, the fan spins and the motor heats up, so of course the power rating stated on the fan isn't all for airflow.
In the simplest heater, whereby current flows through a resistor and heat energy radiates from there, only one conversion takes place, so all the energy is lost, but it is lost as intended. That's why a heater puts out as much energy as it takes in.
In the fan, current flows through a wire coil to induce the magnet to rotate, and the fan attached to that axle rotates, and air moves in turn. That makes two conversions: It begins as electricity, then becomes magnetism, then becomes kinetic energy.
With every conversion, energy is lost.
Mark is right. Surviving on Mars is a battle against entropy at a fundamental level.
Edit: You are right about some heaters being better than others. Radiated heat is better for warming you at a distance. Conducted heat is better for warming your food on your range. Convected heat is better for warming your house.
They are, however, all equally good at the conversion part.
8703018 They could also turn the magic transdimensional air thingey onto MAXIMUM OVERDRIVE and pump Mars full of atmosphere! Like Arnold did on "Total Recall"!
cinemaspartan.com/wp-content/uploads/2011/02/arnold-total-recall-4-650x411.jpg
Totally legit.
8703365
On Earth, there are Heat Pumps, which get around this by cheating. They work effectively like a refrigerator in reverse; they cool the outside and dump the heat into your house. It's not super efficient, but it's better than just turning the heat into electricity (especially as most of the electricity lost to inefficiencies ends up as heat in your house anyways).
However, heat pumps work decently on Earth, with a thick atmosphere and where a "cold" night is still generally around the freezing point of water, less so on Mars. They're also larger and more complex devices, so even if Nasa could save some power with a heat pump on the Mars rovers (I have no idea) they'd probably prefer a simpler and more reliable piece of critical life support apparatus. They definitely wouldn't work at all in space or an airless planet like the Moon, so the Amicitas certainly wouldn't use them.
Which is good for Mark, here, since even if heat pumps would be more efficient putting one in the cave would be like trying to cool your house by leaving the refrigerator door open; it would be heating and cooling the cave at the same time.
Realistically, though, the heaters will barely matter at all. 200 watts of electricity means 200 watts of heat; however, the energy of sunlight on Earth's surface is about a thousand watts per square meter. If Starlight's trick with the crystals creates Earth sunlight equivalent for 640 square meters of plants, that's ~600,000 watts of heating from the light (during the day) and 800 watts of heating from the space heaters (24 hours a day thanks to the battery). IIRC the RTG was 900 watts of heat and 100 watts of electricity, so even it would be a drop in the bucket next to the sunlight.
Though if this seems like a problem, Kris, I would say don't worry about it - Andy Weir didn't, after all!
8703427
It is not as far-fetched as you might make it out to be. Apparently they have unlimited water there, what would stop them from forming a
lakepond with extra water? Only real danger i can see is making the cave too heavy which might cause a crack.Also, as an added benefit, would make a tremendous gift to humanity by the ponies, lake filled even with drinkable frozen water on Mars would truly be a boon to any longer term base. And they could just give it without any real cost to themselves.
Edit:
Damn now that i think about this scenario, conspiracy nuts must be going insane on Earth. I mean what are the odds that first Human landing meeting other crashed aliens happening without some guiding hand, agenda or a purpose are? Also not on Earth only, on Equestria too. I mean what ARE the odds of engine having such problem and then poof them ending up at the same moment in paraller universe?
This is no change encounter, it makes no sense of it being as such.
8703710 Well, there one other little risk: if the water at the top of the cave freezes and thaws repeatedly... it's kinda the exact process that renders mountaintops into rubble. Expanding solidifying water in cracks does quite a number on rigid materials. Hence why ya don't put glass bottles of liquid in the freezer.
Also, Xenu is responsible for this conspiracy and the Chernglerngs are the Thetans.
8703220
Why? Escape velocity of Mars is 5 km/s, less then half of Earth's. The original SD of the Amicia had a travelspeed of ~ 75 km/s, if the jump distance of 6 feet was constant between all mentioned drives (unknown).
So if Starlight manages ~0.07% of the original drive for a much smaler vehicle, then they would have escape velocity in the worst case.
Oh, that's going to be glorious...
I have to wonder if Twilight and the others on Equestria can find a way to send anything other than water through the magic link. I doubt it, if only because it would make survival easy to the point of being almost uninteresting, but still.
8702896
I wonder if it'll play into NASA's brief thought of an active (or activated) volcano [volcanic activity] due to the "explosion" and plume a few days ago?
8704117
They're probably going to wonder about the huge field of crystals appearing on the ground. If Starlight's spell is one way and absorbs all light, they're going to wonder about the huge physically impossible perfect black body appearing on the ground.