MISSION LOG – SOL 388
Well, that might just have been the longest, loudest, and most acrimonious argument we’ve ever had since we all got stranded here.
We got the harvest in, and we cooperated enough to load it all into the trailer this afternoon. Considering all the cave farm’s been through, it was a surprisingly large harvest- three hundred and forty kilograms, or a bit more than enough, by itself, to feed the ponies for the entire trip to Schiaparelli right up until Sol 551. We’ll be taking along a bit more than that, because Dragonfly might need to goop us out of a jam somewhere along the way.
That’s not what we argued about. We argued about how to maintain the atmosphere in the cave farm.
It began when I talked to Starlight Glimmer about my ideas, leading up to the magic option. And when I mentioned it, she totally lost her shit. I’m pretty sure she was blowing off some of the pressure she’s under. She’s obviously been anxious about her batteries and launch systems working right, and she’s the only one who puts in a full eight hours of work every day, in the cave and at the Hab. But whatever the reason, she went absolutely ballistic, and almost entirely in pony-talk. I caught the words for “work hard” and “too much” and “why me”, or things to that effect. Most of the rest of it sounded like Cherry Berry when she’s really pissed off.
Speaking of, the rant attracted the attention of our intrepid pink commander, who wanted to know what was going on. Once she got half an explanation it was her turn to blow up, because she thinks about twice as much of those cherry trees as I do of my own genitals. It didn’t take long for the conversation to degenerate into furious horse noises. Spitfire and Dragonfly had to break the two up, with Dragonfly conciliating Starlight while Spitfire lectured Cherry on the proper conduct of leaders in front of their crew.
After that Starlight and Cherry went to opposite sides of the cave, Starlight cutting hay while Cherry helped the cherry trees shed leaves. She’s trying to give the trees a brief dormancy before we leave, she tells me, even though she’s not totally sure she can do it. But cherry trees are cool-climate deciduous trees, not evergreens, and she says the leaves are tired and full of poisons and need to be dropped and re-grown.
(Side note: we can’t use the fallen leaves for tea. Fallen cherry leaves are very toxic, because all the poisons that normally get cooked out in the tea preparation process are hyper-concentrated in old, fallen, rotting leaves. Cherry hopes to get fresh, new-grown leaves enough for a few brews just before we leave, but only if it won’t harm the trees.)
Eventually Dragonfly got round to me to ask for an explanation, and we talked about the problem while hauling sample boxes full of hay to the airlock for transport to the rover. And it turns out Dragonfly had a solution for that- a pressure release valve.
Neither the Hab nor the rovers contain an automatic air pressure release valve. In the unlikely event that an environment becomes overpressurized, the life support systems simply pull air out and stuff it in tanks- the Hab via the atmospheric regulator and water reclaimer, a small air sump tank in the rovers. If that system doesn’t work, it’s expected that a human being will be on hand to turn valves manually. Thus, according to NASA mission planning, there’s no reason to have an automatic pressure release. In fact, there’s one strong reason not to have it- it’s another hole in the pressure vessel that can fail and cause a breach.
So obviously I didn’t have a spare one, and I don’t have the carefully calibrated spring required to make an accurate one from scratch. But, as it turns out, the pony ship had such a valve, and Dragonfly has not one but two spares. Dragonfly doesn’t know exactly why, except that it might be a fail-safe design, or possibly just recycling off-the-shelf parts for ship components. Both things play a huge role, she says, in pony rocket design.
The automatic pressure release valve is part of a manual system to allow for EVA if the airlocks aren’t working properly. If a pony isn’t leaning on the valve, it automatically shuts- unless the air pressure is more than 1.2 atmospheres. Dragonfly looked it up in the crumbling remains of the ship’s freeze-dried manuals, and that’s what the valve’s rated for. And that’s perfect for my overpressure issues, which I admit might be entirely unfounded, but I want to be sure.
But that got me thinking… Dragonfly’s spare pressure valve solves the main problem with using the MAV fuel plant to pump in Martian air from outside. Of course, running it full-time would waste power, not to mention it might risk smothering the plants in the other direction. Plants need to breathe in oxygen at night when they can’t photosynthesize.
But… but yeah, I think I see a way to make this work, with no magic involved. Just my tools, some leftover NASA pieces of equipment that were never meant to be put together, and a software patch courtesy of some big brains back on Earth.
Yeah, I think this could really work.
Now the question is, how do I explain my new idea to Starlight without pissing her off for real this time?
Hurray! The plants will survive!
Huh. Wonder why no one else thought of that. Granted, it may be because of all the immense stress they're under, but it seems rather simple in all honesty. Though, the simplest of solutions could stare us straight in the face and we still wouldn't notice them until it was too late.
Ah, Mars, why must you be such a cunt?
Some good old human engineering!
Everypony needs hugs! Hugs all around!
The pressure relief valve for the crew remembers the pressure relief valve for the ship that would work for the farm.
One valve in the wall would take complex airseal fields during installation while drilling, but two valves, on in each airlock door would double the overpressure?
The worse pressure relief valve that failed was on a Soviet spacecraft on reentry. Three men in a two man and suits capsule meant they couldnt wear suits.
9076814
Put it on one door and leave the other door open on departure.
Look, you're featured again.
Yay.
I haven't slept in DAYS.
HELP ME.
YES! Haha! F you Mars! The cave farm shall last FOREVER!
Worried about Mark, here. He's not drunk, so hypoxia, maybe?
9076880
Okay here's what you do, go on YouTube and find a Warhammer channel called Arch warhammer. I don't care if you care about Warhammer, it'll be better if you don't. His videos are long, detailed, and he's easy to listen to. I find if I'm at all drowsy I'll easily doze off right in my chair. That should set you straight.
I'd like to get on the train of letting the farm die. It's terraforming Mars, and Mars doesn't like that idea at all.
9076802
because Mars.
And now I'm going to bet that this story will end with a scene of cave farm silently repeating it's credo.
I'm here.
9076802
but as Mark pointed out, they still need to suss out a way to regulate the CO2 injection into the cave, as the relief valve cannot distinguish between oxygen and CO2; if they flood all of the Oxygen out of the cave's atmosphere, the plants will die.
Still, this is a problem Mark can solve; that pressure relief valve was the only critical component he was missing.
9076800
Well, they have a fighting chance now; the alfalfa is still going to die out, without anyone present to keep replanting it. And without Cherry Berry, or another Earth pony tending to them; the Cherry trees will be extremely sick by the time the next crew can arrive, unless they can work out a way to reliably trick the trees into thinking winter has arrived, after everyone has already left.
Also, the modified MAV plant may well break down or lose power after they leave; but them's the breaks, this looks like the only way the farm stands a chance of surviving under these conditions.
9076866
That, might actually work.
So, it sounds like they're going to be pumping Martian atmosphere in and exhausting slighty more oxygenated air out. Now if only, say, some exotic energy could convince the planet to keep that oxygen around, then that would be great. Like Tolkien's mallorn party tree replacement. The only mallorn not in the undying lands or Lorien. Although in this case, they're Equestrian cherry trees, there are several of them, and they are the only trees on the planet. Furthermore, they are the only trees from Equestria in this dimension. I hope Mark kept a cherry pit with him.
9076923
Thank you.
9077303 I keep forgetting that.
Incidentally, if unlimited in-cave organic carbon accumulation happens, the next problem will be the cave running out of water as it all gets bound up in that.
But that should take a pretty long time, and in the long term if anyone cares they could come back and install a magic water source. And investigate how nothing else killed it off first.
9076814
Two valves wouldn't double the overpressure. Pressure relief valves don't go off the pressure differential between inside and out, they go off the pressure in the interior.
9076994 It's not the planet you need to convince, it's the solar wind. Thanks to lacking a strong magnetic field, the solar wind constantly strips atmosphere from Mars. Stars can be notoriously pushy, and are prone to ignoring their planets' needs.
so spitfire, in your numerous experiences leading crews in space travel and the like which is the more proper way to act?
bench a temporarily injured teammate to recruit an up and coming star from a small town thus causing numerous problems for multiple ponies because your a jerk?
or take the completely off handed approach when training new potential recruits and then responding to one recruit endangering civilian lives with 'huh thats an unusual method'.
please tell me from your vastly superior mind, what would you consider the right way?
Now they only need a way to simulate winter on a yearly basis, and the cherries are set. Then someone decides that Martian Cherries are worth enough money for a roundabout trip. And it might well be if humanity can copy the Sparkle Drive.
9077413
You obviously missed the memo where none of those things ever happened.
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Don't ponies do it by running around?
It doesn't need to have calibrated spring, just screw for controlling spring pre-load.
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Stick it in, screw the bolt in until it stops speaking Ancient Changeling and then a tiny bit more.
9077378
This is actually one of the reasons colonizing Mars is unlikely to be possible IRL: any terraforming project would need to find a way to give the planet a magnetosphere, a monumental task. (And even if you solve this problem, the amount of oxygen required means that it’d take millennia, at BEST, to get the atmosphere breathable.)
9077809 Eeeyup.
That's the showstopper for it. The only hope for it, in this instance, is if something (like a HUGE repulsion spell) managed to not only hold back the solar wind, but also feed on it to do the task.
Is this a meme in the community or something? I've seen it several places, though my first thought was Think Pink's work.
9076923
"But Doctor, I am Arch Warhammer."
9077809
It's not really that hard. You only need a relatively large space-station at solar-Mars Lagrangian point that pumps out a magnetic field.
9076880
There is also channel ChessNetwork on YouTube, if you don't play chess the better. Author has nice calm voice, just close your eyes and listen: Lopez Schliemann defense with that five, white reinforces e4 with a piece recapturing and now supporting e4 once more with a piece, queen e7 castles so...
https://www.youtube.com/watch?v=2m5oXlZ_e_A
9076880
Bob Ross' The Joy of Painting is amazingly soothing.
Actually, I wonder what the ponies would think of that show.
9076383
All farms are mixed farms.
Untill they actually put a battery in a pop tent with potatoes, They cant know. They obviously think they know, but that doesn't count for me.
9077334
a pressure release valve that doesn't use the difference between internal and external pressure would be comparing internal pressure to some static (de-)pressurized container. comparator valves would thus be much easier to build.
9078483
Ugh, yeah, didn't think through everything I should have. Yeah, that'd be the case, so Booster Spice was right.
9078360
Someone needs to write that.
This valve idea might work, and the previously mentioned Hab CO2 filter system might be used as the brain of the apparatus. It aims to breaks down CO2 so theoretically it could be used as regulator of some sort, when it sets itself in high gear it makes sure the CO2 intake will not happen through the valves, and when it turns off then it instructs opening of the valve for CO2 intake.
I am not sure how it would work mechanically but i am quite sure it could be done in efficient way.
The pressure valve is a convenient option, but it honestly isn't needed. Again, in reference to the bottle garden (link) concept, plants only use photosynthesis during the day to break down sugars like glucose to fuel the plant's growth, using the carbon from CO2 and dirt for more plant cells.
At night the plants 'breathe' the other way, using O2 and phosphates to recombine various minerals and amino acids into sugars for the next day's active growth while releasing small amounts of CO2. Thus the pressure should remain the same and the plants will grow naturally.
Once the plants start to overgrow the area, weaker older plants will die and become mulch for the new ones, so even in bottled gardens the nutrients in the soil aren't lost as the cycle continues.
All in all, the cave should be able to last indefinitely as long as there's sunlight available. Water would be the secondary issue as it tends to settle in low points of large areas, even when in the air, but that was solved with the growing water crystal enchantments. Plants are mainly spare carbon scrubbers, CO2 helps them grow but it's not the main focus in a plant's life cycle.
IMO it would be sufficient to increase the CO2 level to 5% after removing the magical life support and before leaving.
The cave should be sealed then, the CO2 feeding pipe in the internal doors welded shut and then the external door closed too.
The pressure valve is an unnecessary failure point that can rust and dehermetize the cave after few years or decades.
And Mark and the ponies want the cave to exist indefinitely.
Besides, the proposed system would work by replacing the air that is about 80% nitrogen by the nearly pure CO2.
That CO2 + water would be converted to the plant matter and oxygen.
That means that the atmospheric nitrogen would be slowly replaced by oxygen.
P.S.
I don't know what gaskets the ponies airlocks have, but I'm sure they are not eternal.
So, for the cave to survive longer, it would be beneficial to weld the internal airlock shut (of course from the outside).
But it would make very hard for the next explorers to enter the cave. Or the same explorers, if they failed to launch the MAV and had to return to their habitat to wait for the proper rescue mission with a lander (assuming that they would get food supplies for the return journey from the support mission).
Very excited to see what Mark will come up with as this can be his Opus Magnus as a Botanist. Leaving a self-sustaining farm on Mars. He'll be a legend among botanists, biologists and other nature sciences for a decades, possibly centuries.
Best of all, did so with tools not specifically designed for it.
*reads all the scientific talk*... I like pie!
Dragonfly can always just goop them up to make them behave.
I finally caught up, whoo! Seems like the crew is getting closer and closer to liftoff. I hope they save the cave #savethecave
side side note a single cherry leave will kill a 1600 pound horse vary easily in about 48 hours and it is not nice to see, i was helping a friend with a horse we though had colic nope there was a cherry tree across the field we think 1 leave blew in.
he lost a 15.3 hand warm blood gelding.
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Yeah the failure point of the pressure relief valve worries me too, and the best Very Long Term solution is a completely closed ecosphere.
But you need to get a carbon cycle set up first for that to work, and the only carbon recyclers in the cave are gut and soil bacteria seeded in.
The cave might NEED the extra carbon to build up a buffer before it's stable.
So keep importing carbon until the carbon cycle becomes stable (but risk the valve and pump failing long term)
Or keep it closed cycle (and risk the plants running out of CO2 before bacteria can produce it fast enough to keep up)
9081305
oh, there's a short gag in the original where Mark ONCE tried to make potato-skin tea. it was terrible. he had to settle for "nothin' tea". "take hot water and add nothin".
Yiiikes. Talk about obsessed. Girl, you knew these things were never gonna last
Well, pony "life support" is just pumping stuff in from their world through the magical connection, so obviously the easiest solution for regulating that is just releasing excess.
Again the format is broken.
Neat chapter.
Perhaps the Cave farm survived but i doubt it.
If I remember correctly, atmospheric regulator stores significant amounts of cryogenic liquids.
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NEIGH WAAARRR
Somehow, Backups like dragonfly and fireball are the sane ones.
No matter how long the cave farm survives, the batteries and wild magic crystals left behind will be the real price.