TO: Theodore Sanders (tsanders_admin@nasa.gov)
FROM: Venkat Kapoor (kapoor@ares.nasa.gov)
SUBJECT: Reports on Mark Watney
Attached find the summaries for the reports on the topics you requested. It makes pretty grim reading. If you need the detailed reports I can send them, but I think this pretty much says all that needs to be said.
I’ve instructed everyone involved with the making of these reports that NASA’s official policy is optimism. Mark Watney and our alien visitors WILL survive. We WILL send a ship to bring them home. Even so, I have my doubts that we can keep these facts under our hat indefinitely. When the lid comes off, we need to be ready.
Venk
TO: Venkat Kapoor (kapoor@ares.nasa.gov)
FROM: Dr. Ethelbert Keller (keller@nasa.gov)
SUBJECT: Nutritional Needs of Mark Watney
Report attached.
I’m sorry I can’t do more than make guesses about Watney’s alien guests. We have to take Watney at his word that Dragonfly and Fireball (Orange Random and Tall Boy) are assured of full rations for however long it takes to be rescued. As for the three creatures Watney refers to as ponies, I am told by the veterinarians I've consulted that alfalfa is as close as can be found to a perfect single-crop grazing diet for equines. The diet would still put them in danger of sodium deficiency (no table salt in their diet). Symptoms include craving for salt to the point of licking anything and everything vaguely salty; loss of appetite; fluid retention; and in advanced cases, nerve damage. Watney should expect a lot of tongue baths whether he likes it or not in his future, as he is probably the only safe source of sodium chloride on Mars.
Watney’s own situation is much less amusing. If he relies on potatoes and the vitamin supplements from the Ares III medical store, he will run into serious protein deficiency within thirty sols of switching from meal packs to potatoes. Symptoms include loss of mental acuity, loss of energy, metabolic dysfunction, muscle loss, enlarged heart, proneness to injury, slow healing, and insulin resistance.
Alfalfa is edible by humans and has a high protein content, but we can only digest flowers, leaves and the younger roots and stems. Beyond a certain point the stems become too fibrous to digest. Alfalfa seeds are high in certain amino acids that cause metabolic imbalances and loss of thyroid function. And since human digestion is not evolved to handle cellulose in large quantities, our ability to extract useful protein from alfalfa is limited. Unfortunately, it’s all Mark has once the food packs run out.
Please advise Mark to plant more alfalfa if possible and to cook and eat the leaves and uppermost stems from each harvest (and flowers if available) while fresh. Dried alfalfa is much less useful, but even drinking alfalfa tea would help a little. This will slow, but not prevent, his protein loss. The only certain remedy is to get him high-protein rations as soon as possible. In the meantime, to reduce protein loss and limit risk of injury I recommend Mark’s physical activity be limited to only that absolutely necessary for his survival and rescue.
Keller
TO: Venkat Kapoor (kapoor@ares.nasa.gov)
FROM: Sue Douglass (douglass517@nasa.gov)
SUBJECT: Cave Permafrost Insulation
Preliminary report attached. Long story short: months at best.
Tell Mr. Sanders that he’s correct that the inside of an igloo can be made warm while the outside is quite cold (for Earth values of cold). Ice on Earth is a reasonably effective insulator in the short term. By a process of partial melting and refreezing a freshly built igloo becomes both more airtight and more structurally sound. But Mr. Sanders overlooks a great many factors that render the comparison inaccurate.
First, we know very little about the properties of permafrost and regolith mixes, particularly as they exist at Site Epsilon. We know that lunar regolith makes a very efficient insulator, but testing on Martian regolith to date has not included either pure layers of water ice between regolith layers or a permafrost mix of soil and water, both of which occur on Mars.
Second, the air pressure inside an igloo is roughly the same as outside. This is not the case with the Site Epsilon cave, which the aliens have pressurized to roughly one bar of pressure as opposed to six millibars on the surface.
Third, if a small hole opens in an igloo it doesn’t immediately grow larger through erosion caused by air flow.
Fourth, igloos are primarily warmed by body heat or at most an oil lantern. Igloos with large heating systems installed inside tend not to last very long. The Site Epsilon cave uses a combination of electric heaters, warm air circulation, and a hydronic ground heating system to make the air and ground warm enough for plants to grow- which means raising the temperature an average of seventy degrees Celsius above the mean outdoor Martian summer temperature. In winter it's well over a hundred degrees Celsius above the mean. That’s almost double to triple the temperature extreme most igloos face.
Finally, the permafrost layer above the cave is on a slope. Melted ice will not merely run down the walls and re-freeze. It will seek the lowest available level via the path of least resistance, eroding regolith on its way. Given enough time some of it will find its way to the surface downslope of its origin, possibly causing a landslide of the kind we are already familiar with from Opportunity and Curiosity. Such a landslide would inevitably reduce the layer of regolith and ice protecting the cave farm, leading to further leaks and an eventual breach.
The good news is, the primary cause of igloo collapse is heating from outside. That is practically the only problem Mars isn’t going to throw at us.
I’m currently locating sources of synthesized Martian regolith for heat transfer experiments. Details on those experiments will be on your desk tomorrow. In the meantime, until and unless the cave is rendered truly airtight without regard to regolith or permafrost, my recommendations stand.
Sue Douglass, Ph. D.
TO: Venkat Kapoor (kapoor@ares.nasa.gov)
FROM: Michael Bendarek (mbender33@nasa.gov)
SUBJECT: Gilligan’s Raft
I finally have the numbers for you. Our four-legged alien friends aren’t going to like them much. Break it to them gently.
The attached report is preliminary, but I had to take the man I had working on it off to begin work on finalizing trajectories for Project Sleipnir. It took a while to shake this out of him, because he says it’s not finished. When I stopped him he was analyzing the alien shipwreck and making mass estimates based on how much could be cut off the fuselage. I had to promise him I’d let him finish the job properly once I had the trajectories in hand.
According to the information given, when whole the alien ship had a thrust:weight ratio of about 2:5. Considering its construction, that’s damn impressive. Given infinite fuel, the ship could almost hover on its main thrusters by itself on Mars. With the outer skin ripped off it, plus the other loss of mass due to scavenging, the ship could probably just about lift off right now, given sufficient fuel.
But sufficient fuel is a major problem.
According to the aliens, the ship originally converted a form of energy unknown to us (“magic”) into kinetic energy (thrust). The “magic” was stored in a series of batteries, of which only two survived the crash. Those two are made of a lightweight but durable crystal, type unknown, plus metal and electrodes of some kind, the whole package about 27,000 cubic centimeters in size and massing an estimated seventy kilograms. One hundred such batteries would weigh seven tons. Even with the materials cut off of the wreck, we estimate that extra mass drops the ship back to hovering at best. We are told the original batteries were larger, but we can't verify that from the pictures.
But weight isn’t the killer issue. The issue is the energy you get for that weight. According to the aliens, the two batteries which survived the initial accident were able to power an engine full burn for only three seconds combined. We can therefore estimate that a full array of one hundred such batteries would provide a single burn at full power of two minutes and thirty seconds. As you know, that’s roughly the burn time of an Ares MAV first stage alone. If we could lighten up the ship somehow to get it to orbit in two minutes and thirty seconds, the acceleration would kill any crew inside.
Using what’s left of the Ares III MAV and MDV wouldn’t help. The MAV has no remaining cabin, and the MDV cabin is breached. The MDV thruster thrust:weight ratio is only 1.05 at best, just enough to slow the ship down to a safe landing once the drogues are no longer useful. Its hydrazine monopropellant is hypergolic, but there’s not enough of it and we can’t make more. The MAV descent engines use hydrazine, but its fuel plant produces methane for its two ascent stages.
Finally, two of the ship’s eight maneuvering thruster banks are reported as destroyed in the crash. It might be possible to reposition the remaining six into a configuration that would provide total control, but there would be zero margin for error both in installation and in piloting.
In short, outside some radical alterations to the remains of the alien ship (assuming the engines could be attached to the ship again afterwards), it can’t make orbit without killing the crew. This is going to be a major blow to the aliens, so try to find some way to soften it.
Mike
Astrodynamics
TO: Venkat Kapoor (kapoor@ares.nasa.gov)
FROM: Mark Watney (mwatney@ares.nasa.gov)
SUBJECT: Care to buy a farm?
We’ve looked at the recommendations the geologists sent us. Here’s our responses:
Lowering the air pressure: No go. The pony air supply is a direct link to the atmosphere of their home world. Whatever the pressure is there, it’s going to be here. The only way to lower the pressure on our end is to make a leak somewhere, and doing that will make the air supply shut down. The ponies don’t feel like losing all their atmosphere to Mars, or as I’ve taken to calling it, “Planet Spaceball”.
Lowering the heat: We’re removing two of the space heaters. That’s about all we can do. Again, the air is straight from the pony world’s atmosphere, and we need to keep warming the farm soil to allow the alfalfa roots to penetrate as deeply as possible.
Don’t mess with the support pillars: Duh.
Don’t twist off the crystals from the walls: What, do you think Bruce Banner turned up along with the ponies? Listen, if I had the Hulk here I wouldn't have him picking rocks like fruit. We’d just all load up in the alien ship and have him kick us off Mars! Stupid planet deserves a green gamma-powered kick in the ass anyway.
The crystals are cut by magic laser. Starlight's horn is the only tool we have that can cut them. No torque of any kind involved. The only danger is that removing the weight from the walls might cause a release of tension. There’s nothing we can do about that.
Seal the cave: That’s going to be a long-term project. Starlight’s spell (according to her) was designed to close up existing holes that can be seen. She’s doubtful she can use it on walls where she hasn’t stripped off the crystal layer completely. Also she doesn’t have the energy to do it all at one whack.
But we have a long-term plan that might work. Sol 109 is three weeks from the day the Hab blew out and Starlight broke her arm. It’s also the day we’re due to dig up the cave’s seed potatoes, cut them, and replant them for a full crop in the cave and the Hab. After that we get our first alfalfa harvest. Those things can’t be put off, and we need Starlight’s magic to help with both. The harvest will probably deplete the magic batteries, and after that we need to cut more gems for Fireball’s meals. But after that we can get started on making new magic batteries.
According to Starlight, making magic batteries is one of the easiest spells ever. Practically any magic object is at least part battery, she says. The main difficulty is finding and cutting crystals of the right size, without flaws, for the purpose. Apparently there are places on her homeworld that make the cave farm look dowdy. She was surprised when I told her that the quartz here was gigantic by comparison with Earth crystals.
The more batteries we have, the more magic we potentially have. And beyond a point we’ll have enough magic to seal the cave properly. I don’t know what that point is or how long it’ll take, but it seems like the surest and safest course. In the meantime Starlight's going to work on a better spell for sealing the cave away from the pre-existing holes.
Tell Astromaterials that if they come up with something we can actually do, we’re willing to give it a shot.
Watney
TO: Venkat Kapoor (kapoor@ares.nasa.gov)
FROM: Beth Johannsen (johannsen@ares.nasa.gov)
SUBJECT: Radio test
On Ares III Mission Day 230 Hermes made successful contact with alien spaceship Friendship on all five preset wavebands. 108.4 megahertz produced the clearest signal, but not sufficiently to distinguish it. All signals were faint and with static, but voices were audible and understandable. Full details of all tests, including audio recordings of all transmissions and receptions, attached.
As Hermes approaches Earth the signal from Friendship will grow fainter due to losses from transmission distance. We are currently near the edge of voice communications range. If diagrams of the alien radio wiring are available, I recommend creating a procedure for Mark to build a telegraph key for the radio. I’ve already written a program to allow Hermes to transmit an audio tone that can be used for Morse code. The crew will need drill on identifying and using Morse code for this to be workable.
Beth Johannsen
Ares III systems operator
8777714 NASA will only be sending the most important/interesting incoming emails to Mars. Spam is going to be weeded out. Sadly, so will the fanart (some of which I described in today's writing (4000 words).
"Watney’s own situation is much less amusing. If he relies on potatoes and the vitamin supplements from the Ares III medical store, he will run into serious protein deficiency within thirty sols of switching from meal packs to potatoes. "
Watney->NASA 'No, I am not asking Starlight if she can induce lactation so I can have protein'.
More seriously - potatos have some protein in - 2% or so, and are of reasonable quality protein-wise, adequate for a minimal diet, containing all the essential amino acids as far as I can tell.
https://en.wikipedia.org/wiki/Complete_protein
Also, if you heat the perchlorate, you get chloride.
8777781
Awww
...
Kinky.
Are Dragonfly's secretions edible? Might it be possible to chemically extract proteins from them?
8777781
I honestly think they should let one piece of faux spam get though. Get some of NASA’s best to combine as many spam tropes as possible into a single piece of Ur‐spam. It’d be good for a laugh and might lift morale.
Huh. What sort of inflow /outflow does this life support crystal have? If they can't put the intake into a lower pressure environment, then what about putting a pressure reduction valve on the outflow?
Would Chicken Of the Forest grow on the older woody alfalfa stems? Or if only 1kg could be sent on a Zorb aerobreaker soft impactor, how much would have to be chick peas or othre high protien beans etc, especially low methoane versions?
Pycrete was only ever considered with random woodchip, and not spun quartz, silica fibre, glass fibre, etc, especially given Mythbusters made a test small boat out of newspaper and got very good results out of just an inch thickness, given how quickly it melted through under forced water flow heating and no active cooling or extra insulation. Aerogel the wall for smoothing and insulation then put a pressure sheet inside that. A liner can be microns thick of stressed plastic as long as nothing touched it, but thats what more aerogel on the inside would be for with a second encapsulation layer? Wonder how much area say 100kg could handle.
I use dual layer washing line. A fibre core which takes all the stress, and an outer smooth plastic coating thats loosly fitted, that is far more elastic, and takes the enviroment damage instead. Quite often using a pair or products working together is almost as good as perfect unit material and vastly cheaper to supply.
Still think they just need to find a weak enough feed in the water supply that it can be used as a thrust assist, without blowing apart the local universe crystals? Or they cant be paired with Equestrian life support transiiton crystals using Starlights light transfer spell? Then you end up with The Flying Bedstead. Main thrusters fire down for long enough to keep the thing off the ground as the other thrusters accelerate it sideways, to aerodynamic lifting speed, then everything slowly points up, now accelerating slowly out of the atmosphere?
Well, at least theres one good thing about these stories, lets you think about what minimum you could take to ahve a far better range of options available overall. A one ounce half silvered balloon for a comunications antenna could be how large if made so thin it could take little over Mars pressure to fill it before its velcro vents popped?
Maybe some Apple pips might find their way into the supply kit?
This is really easy to resolve. They can't control pressure on the Mars end. They have contact with Equestria though and they can have Equestria put their end through a pressure reduction setup of their choice. Equestria can certainly manage it with their resources.
There are enough sodium chloride deposits on Mars that there's bound to be one in range compared to Pathfinder. They can make a trip out with Starlight. Starlight can then use the same spell she used to summon only the perchlorates to summon only the sodium chloride. She made basically 100% pure perchlorates with just a chemical formula to go by. So do the same for Sodium Chloride. Make sure to lay out a tarp underneath the salt ball the spell makes before she shuts it off. Salt is stable against plastic tarps and bins so this isn't the problem it was with perchlorates. Bring home a couple hundred kilograms of pure salt, be set for the next couple years.
Depending on the makeup of their current location, she could possibly just gather enough salt like this without even a road trip.
I'm glad you're actually considering single food nutritional issues though.
Can't Twilight research a spell to do this job on Equestria and then communicate it? She has access to libraries, other researchers, and a ready supply of magic for testing without wasting a limited battery.
Though still not sure why they can't give Dragonfly a big chunk of alfalfa and have her puke seal most of the cave. They're producing a lot more than they need. Might not be enough to do it all at once, but she could get started.
Kinky.
Uh, phrasing, Mark?
8777830
It doesn't have to be that complicated. Just put the life support crystal in an airtight box or bag with a pressure regulator to the outside. 1 atmosphere inside the container with the crystal, lower pressure outside. They could make a bag out of hab canvas and tape, for example, and the valves should be salvageable from the MAV, MDV or Amicitas. At worst, the ghetto solution to not having a valve would be to prick a small hole in the bag where you have put some tape to prevent the hole from widening and the bag ripping open.
8777855
but then we wouldn't have a story would we?
Salt really shouldn't be a problem if starlight can replicate what she did in the cave with the perchlorate. Just do that spell for NaCl and she can pull pure salt out of the ground.
Couldn't Starlight use her "percholare drain" spell on any salt she find to make it edible? I mean, if we are talking about a 1kg pile that is 50% dirt, 30% salt and 20% perchlorates that would only be 200g of explosives. A small enough ammount to deal with safetly with a sample bag or just bury back in the ground. Hell, couldn't she modify the spell to just drain teh sodium chloride instead?
As for the air pressure problem: They could just ask Equestria to feed the air from a very high altitude where the pressure it smaller. Just move one end of the hose to the top of Canterlot or Cloudsdale and they are set.
Well, that's a whole lotta good news... not. And here we thought Mars was finished trying to kill everyone. Apparently, if it can't kill them quickly, it's going for the long game.
If Starlight could pull the magic exploding powder out of Mars soil, could she do the same but leech salt instead? Pretty sure it wouldn't have to be a lot, nothing like the small mountain of exploding powder.
8776661
YOU. I also like you.
8777855 The difficulty with having Equestria do it is that, at least for now, they can only communicate by telegraph. It's slow and it makes equations and diagrams really, really difficult to get across. Twilight can give hints, but anything more involved is going to be trouble.
And in order for Dragonfly to seal the cave, she had to projectile-puke (or spit) up with sufficient precision and force to get the goo into the tiny gaps between each crystal. The difficulty here is on the scale of "let's REALLY hope things never get so bad we have to try this".
8777872 The book has a lot of black jokes of this variety in Mark's logs.
I think we need fan art of Mark getting a tongue bath from the tree ponies. With Dragonfly joining in cause she feels left out.
8777877 That is actually a brilliant workaround. If I feel like it I might even steal it.
The main difficulty will be in devising a pressure regulator that can be left to run by itself.
Couldn't CSP/ESA feed cool air into their crystal? Not an optimal solution or permanent. But seems like they could aim an air conditioner or two at their crystal.
8777892
What about the air pressure and salt solutions though?
The magic density was getting enough enough for Spitfire to fly as early as the days before the Hab breach. So Dragonfly should be getting to the point she can fly as well which lets her get right up to the points. Though alternatively she could use her ability to make things like ropes and shape a pressure rated tarp. Then just glue it to the cave roof. This would also serve as a tremendous boost to the insulation of the cave, thereby reducing the melting of permafrost.
I suppose it's fair enough that it's very difficult to convey diagrams and equations. Though Twilight can at least advise her on how to go about it after figuring out how to do it.
Maybe Starlight can use her utterly terrifying perchlorate-separating magic?
Well, sweat certainly contain sodium chloride, but in small amount, and all distributed in the body, so the more he sweats, the more sodium chloride the body have superficially, that is if he doesn't take a shower, in which he doesn't if all of them are trying to do th minimun to save shower materials, so the ponies will be ended up licking a sweat with a lot of bacteria, dirt, and dead skin, I imagine the ponies can create a schedule; BUT, there is another source for a more concentrated dosis of sodium chloride and way less dirty that Mark can provide, and easy to clean, mostly because is a small area, but nobody will like it and perhaps the ponies will prefer getting sick, "Cowper's Fluid", is alkaline, clean, and most of it is sodium chloride, Mark wouldn't need to sweat nor make any physical labor, so everybody wins, well, except the ponies pride XD.
I'm guessing that was Rich. Gotta love the guy.
8777872
I think that was deliberate. Mark seems like the kinda guy who puts gallows humor in everything he does.
8777905
That will certainly be best because the other options available are not so good.
8777908
Did you just suggest what I think you suggested?
WHEN THE HELL DID STARLIGHT BECOME ANTHRO?!
8777937 She didn't. But I chose that word deliberately, considering how often ponies use their forelimbs as manipulators. For Mark "arm" is just as valid as "foreleg" when referring to his friends and a lot less awkward.
If the air comes from a direct link to Equestria, is the same true for the water? If so, why can't they dissolve useful substances in it, such as salt? Arrange a certain time to send a batch of salt infused water. In fact, vitamin supplements too!
8777925
SUCC (seriously look up the gland he is talking about)
8777958
I think it's because the more stuff there is in the water the more unstable the transfer is. In Changeling Space Program they mention trying to send apple juice and it ending up "burning and sticking everywhere while smelling bad", so you can deduce that more complicated molecules could end up subjected to too much stress.
8777925
Well, the option is there, and is up to them what are they willing to do in order to survive until the food arrives, they may find that the marks normal rate of sweat is enough, or maybe not, they may find another external source of salt in mars, and use starlight to clean it up so its ok to consume, regardless, the option is there.
8777896
Well, jury rigging this kind of thing is what NASA does and looks good doing. It would be just like the scene in Apollo 13 where the engineers figure out a way to put the square peg in the round hole, i.e. get the square CSM CO2 canister to work with the round LEM CO2 canister socket, with just the plastic bags, duct tape and assorted crap they had aboard. Venkat or Terry should just ask Bruce to figure out a way to step down the pressure with what Mark has on hand, test it in a pressure chamber on Earth, then transmit the instructions.
I love the spaceballs reference... Spaceballs the lyrical Comment chain start
If youre livin in a bubble and you havent got a care... Then your gonna be in trouble cause theyre gonna steal your air.. CAUSE WHAT YOU GOT IS WHAT WE NEED AND ALL WE DO IS DIRTY DEEDS WE'RE THE SPACEBAAAAALLS!!!!!
8777908
Congratulations, you win the "Craziest Survival Suggestion" award. I doubt anyone's going to be able to top that.
8777998
A way to top that is get chuck norris to go to mars and beat the planet into submission
8777998
Thanks, is the first time I earn something, so I take what I can get :D.
This was the point at which I properly understood the level of 'oh shit' they're facing with the cave problem.
Also, am I right in understanding that Hermes translated Amicitas as Friendship, and that's what the ship is actually called?
8777896
You could make an improvised pressure regulator using a tube and water, I think. Put the tube a certain depth in the water, full atmospheric pressure air on the other end, and the cave on another, and when the air in the cave gets thin enough relative pressure would force it to bubble out. Similar to a barometer, really. Relative pressure would depend on how deep in water it was (and it would gradually drift off point as the water evaporated).
Downside is that one atmospheric pressure is equivalent to 34 feet of water, so to reduce it to .1 atm you'd need like a 30 foot deep tube of water. So maybe not as practical as it seemed at first. You could make a smaller one with some fairly basic hydraulic principles but that might take more complex part-making than the astronauts can handle.
8777892
Asking the ESA/CSP to limit the air pressure at the source was the solution I immediately thought of too. They wouldn't need to communicate any complex formulas or anything. I think they could make the request in a single sentence. They just have to ask them to limit the air pressure to X% of normal or 0.XX atmospheres or whatever unit they use. Then Twilight could use whatever method she comes up with to accomplish it. They could move the crystal onto a cloud and take it up to a higher altitude. That would reduce pressure and temperature. Or they could put it in a temperature/pressure-controlled chamber.
8777882
8777888
8777905
I mean yes, thats exactly how it could be solved. Summon the NaCl out of the rock instead of the Percolates and its done. Its important to know that Earth doesn't know that Starlight can do that. 'Magic' is almost certainly on a need to know basis so while the nutritionist may have been told that the perchlorate problem is solved the details are not likely shared.
This chapter is a list of issues earth can see. Some will be easy to solve, others not so much.
Likewise magic is a limited resource....if she is summoning Salt she can't seal the cave. Starlight is not a cure all....her magic needs to be applied to the most important problem at the time. As such salt summoning is likely to remain low on the list until the licking begins.
I imagine at that point, Mark is going to make it far, FAR more important.
8777998
Well, it's not like Starlight a stanger to the source. In fact, I'm sure she was well aware of it. There's a couple hoof prints as evidence of it.
What? Is there sodium chloride in the soil? Is salt reactive in a similar way to the perchlorates if pure? Starlight already displayed the ability to extract a specific chemical from soil. Am I missing something?
Hmm, I wonder.... If NASA manages to get magic working at all, I can see them trying to replicate anything from the instant communication link to the sparkle drive itself.
Sparking magic might need a location with a lot of immediate social bonds and/or a lot of life in general. Sadly the tools to make the tools arent yet displayed.
If the water and air crystals are linked and send water from a tank, is there anything preventing impurities from being sent? Or does it only transmit a very specific chemical compound?
Depending on the framework, anything from salt water at the low end, to a protein smoothie or w.e.
8777896
Pressure regulators are pretty simple though:
A diaphragm valve with high pressure air on one side of diaphragm, opposed by low pressure air and a control spring on the other. Low pressure side gets too low, high pressure overrides the spring, adding air to the low side until pressure reaches the set point
8777781
Right. NASA has absolute control over Earth <—> Mars communications, and there’s no way for Flim or Flam to get their hooves on the ESA/CSP telegraph, so spam is a problem they won’t have to worry about unless someone is criminally negligent.
OK, seriously, Mark is not the only safe source of NaCl. NASA probably doesn't know about Starlight's dirty cheating mineral extraction spell. She can probably summon NaCl, or at least more perchlorates, which can be decomposed with heat. Best do this in small batches, since the decomposition is exothermic, as Fireball demonstrated. It's not like they need that much salt.
Since the sealing spell doesn't seem to be viable yet, I stand by my suggestion of getting Dragonfly to cough up a bucket of something like concrete sealant that they can paint in a thin layer over all the porous surfaces. Even if it takes them an hour for every square meter, that's still the whole farm covered in a couple weeks of 8-hour workdays, less if they take longer shifts of course.
That said, a spell to consolidate porous material into nonporous material would probably outperform hand-applied goop. However, speaking as someone facing problems at work in the realm of ceramics engineering, such a spell would be dirty rotten cheating, much like doing mineral extraction by casting a spell of Summon Perchlorates.
As for the thermal problem, they could probably solve it if only they had enough plastic sheeting to make a greenhouse for their plants. Keep that pocket of air warm, the rest of the cave stays cool. Maybe make it an inflatable structure. That's the lowest material-budget way to do it, barring relevant magic.
8777958
8777964
In other words, a solution won't be an answer.
8777799
Don't you also get an explosion?