MISSION LOG – SOL 195
Let’s talk about food.
Today is my fourth day in a row on the strict potatoes-garnished-with-dried-alfalfa diet. I’m sure you’ll understand when I say I have no desire to talk or even think about that now.
I have 313 food packs remaining for myself and 49 reserved for the three ponies. At two-thirds rations, that’s about 140 days for me and seven days for the ponies. Since we have to reserve seven days of food for the MAV in case we have to attempt a run for Earth, all 49 vegetarian food packs have been set aside for that, plus sixteen of my own.
Each pack averages a weight of about 350 grams. That means the total weight of those food packs is 126.7 kilograms, give or take a few. The weight of the food packs for the ship is only 22.75 kilograms, but the gang of geniuses they have working out how to get us to Schiaparelli and into space via the MAV aren’t happy even about that. If they could figure a way for us to live off love like Dragonfly for a week (one week’s supply of love at full rations weighs 0 kilograms), they would.
The thing is, obviously we don’t have enough food packs for the trip to Schiaparelli plus however long it takes to get the MAV ready for liftoff. That means we’ll have to haul hay and potatoes with us- a LOT of hay and potatoes.
The current plan is to get us there on Sol 501, allowing fifty days for whatever modifications we need to make. Right now the dream team at JSC is estimating a trip of one hundred days, what with delays and the extra weight on the rover motors and like that. Their idea is to basically stick the Rover 1 chassis under Friendship, add a couple of wheels, and make it a sort of travel trailer for Rover 2.
Yeah. A really big, really heavy travel trailer. You might even say a Whinnybago.
And that much weight will gut our daily travel range, which is why the boffins are only estimating an average of 35 kilometers per day, even if we use the Schwartz.
So we’re spending the day today completing the strip job on Friendship, ripping off every bit of the outer skin. Once we’ve done that, we build a huge pile of rocks for the middle to rest on, remove the thrusters and main engines from the tail, and then lop off the back half of the ship. That will require magic, and Starlight insists that no major spells get used until the next round of battery making, so that last step won’t happen for a couple weeks yet. But we’re going to get rid of everything we can, inside and out, in the meantime.
Cabinet doors for the living quarters and galley? Gone. We may go for the cabinets themselves later- the compartment was built around them, so getting them out the airlock door will be a challenge. Copilot flight controls? Good-bye. Two spare flight couches? Adios. (Which still leaves five, three of which were rebuilt using MDV flight seat parts, to be installed into the MAV when we get to Schiaparelli.) And as we can think of parts that won’t be needed either on the trip or at its destination, they get dumped too. The less our custom-built Whinnybago weighs, the less power it takes to make it move, and the farther we can go before stopping to recharge.
But the thing is, we need food, and we need space. Space is a more urgent issue, in a sense, because we have very little of it and we need as much as we can get just so we don’t feel like we’re trapped in a rolling sardine can.
Here’s the deal. The food packs we’re taking on the trip, as I mentioned, mass over a quarter of a metric ton. But they’re packed specifically to be compact and to stack perfectly, so they take up as little room as possible. The pony ship originally had storage space for over 600 food packs, so the cabinets will hold the ones we have pretty easily.
Raw alfalfa and frozen potatoes aren’t as compact- or even as light. It takes about a kilo of alfalfa and/or potatoes to equal the calorie load of three-quarter meal pack rations (about 800 grams). The potatoes take up about half again the space that meal packs do. Hay rolls take up double the space of meal packs.
Luckily we also have Fireball, who gets by on a couple bites of quartz because quartz is damn dense and heavy. But we’ll still need a minimum of 157 kilograms of quartz for him for the trip.
So: for one hundred and fifty days, we need to add 607 kg to the load, on top of the 127 kg we already have for the remaining food packs. In round numbers, that’s three quarters of a ton and enough space to fill all the cabinets and the bunks in Friendship’s habitat compartment. And that’s before we load any of the other shit we’re going to need.
That’s too much. We’ve already been told that the trip will rely on the Friendship life support system, linked up through the tow hook couplings to Rover 2. No oxygenator, no water reclaimer, no atmospheric regulator, and not more than fifty liters (50 kg) of water as an emergency backup supply. And if the weight budget for this trip is too tight to carry along the main backup system for a thing that absolutely can’t be repaired if it breaks, that’s when you know NASA has pushed way past safety margins and into Are You Fucked In the Head Land. We can’t afford three-quarters of a ton for food.
I’ve proposed two solutions. First, figure out some way to make the trip shorter. One hundred sols in transit, to be blunt, is an absurd amount of time anyway. And the shorter the transit time, the longer we get to spend in the relative spaciousness and security of the Hab, and the less food we have to haul along on the trip.
The other solution is for me and Starlight to duplicate the Pathfinder trip. Rover 2 as currently modified, plus the fourteen solar panels we used for that trip, can travel twice as far per day as the estimated top range of the Whinnybago. So I carry a bunch of food packs- one hundred days’ worth, basically- and leave them at a cache ten days’ travel towards the MAV (say 700 km or so), someplace where we can find it easily on the trip itself.
(Why a hundred days? Ten days in Rover 2 will be twenty days for the Whinnybago. Five people will be eating meals for those twenty days, which means when the rover and trailer reach the cache, the number of total meals eaten will be one hundred.)
This second solution has problems. For one thing, it only saves a little less than eighty kilograms. It requires me to be shut in the Rover with Starlight (or somebody) for another twenty day stretch, and the first time we did that we might have killed each other if Mars hadn’t tried to kill us both first. And the first time we did that we had sealed meal packs, not loose, prone-to-spoilage hay and potatoes. But the boffins might be able to turn the idea into something workable.
I’d very much prefer that we work out some way to speed up the trip. It’s the more sensible solution. If we cut the transit time in half- averaging 70 km per day, say- that cuts the food weight by one-third. Saving a quarter ton would be great.
But for me, the most critical food-related thought of the day is that I will not be able to consume any non-potato, non-alfalfa food until Sol 412. Two hundred and seventeen sols from now.
That reminds me: I don’t know how much salt weighs. We’re going to need plenty. In fact, we’re running a bit short right now. I need to talk to Starlight about that.
For now, though, back to work stripping Friendship of everything nonessential, like skin, bolts, cabinet doors, landing gear, wings, thrusters… you know, pissant unimportant things of that nature.
I shouldn’t joke about that. I don’t want to even guess what they’re going to ask us to pull off the MAV. I get shivers just thinking about that…
The crystals embedded within the standard life support system used by all Equestrian spacecraft were corundum- ruby for hot water, blue sapphire for cold water, green sapphire for the air. The crystals were durable, non-flammable, and among the most amenable to enchanting, but a strong enough impact or shockwave could cause them to crack or shatter. With this in mind, the life support system of Amicitas included pressure-wave baffles to limit explosions and small shock absorbing springs to protect the crystals in case the ship hit something hard.
Each crystal was mystically linked to a larger crystal from the same cutting back home millions of miles and several universes away. The large crystal took up water or air on one end of the link, and it came out of the smaller crystal at the other end, continuously, without pause, for as long as the system was active. The air crystal went a bit farther, absorbing and sending air through one side of the crystal, returning it through the other side, allowing for air circulation and eliminating any chance of carbon dioxide buildup.
When not active, the spell interrupted itself. The crystals remained magically linked, but the smaller crystals no longer received or transmitted material until reactivated by either end.
Once you got past the brain-melting complexity of the enchantment required to turn the joined crystals into de facto ends of a magic wormhole, the system was simple and effective. It had only one major flaw, a flaw which Twilight and over a dozen unicorns and non-unicorn scientists and wizards had worked without success to eliminate. The magic link, the teleport-turned-wormhole, handled ordinary air, water, and very simple, stable molecules without a problem… but it absolutely hated complex molecules.
Simply put, almost anything that would burn would, sometimes, do so spontaneously at the other end of the link. This didn't mean there was, for example, a thirty percent chance of all of it going bang; the "sometimes" referred to each individual molecule. If you put in, for example, half a gallon of ethyl alcohol on one end, what came out at the other end was about seventy percent alcohol, thirty percent water, molecular hydrogen, carbon dioxide, etc., and enough heat to ignite the remaining alcohol if an oxidizer was present. This was done multiple times, with alcohol, with petrochemicals, with a host of flammable liquids and solids, with varying levels of destruction and/or flame.
One infamous experiment involved actual cupcakes. The heat and waste products of the portion of carbohydrates that decayed in transit turned the portion that didn’t decay into a disgusting hot slurry that spattered all over the receiving end of the link.
Ponies, led by Twilight Sparkle, experimented to turn this into a workable rocket engine. The temperatures involved, plus the shock of ignition and air expansion, tended to shatter the life support crystals within seconds. Four years after the invention of the system, the experiments continued, with only modest results at either making a rocket or preventing the system from becoming a rocket, depending on the aim of the experiment in question.
In early days the air system transmitted a pure 75-25 nitrogen-oxygen blend. Experimentation and refinement of the system later determined that ordinary air would be safe, even with its traces of methane. This was fortunate, considering the effects of prolonged spaceflight rations on the digestive tracts of astromares. Trace methane would partially dissociate, oxidize, and disperse, barely raising the temperature at either end. It was, under normal conditions, a non-problem.
But just in case, each life support system was enchanted on the Equestrian end to shut the valves and power down the other end of the system if the crystal on either end of the link warmed beyond a certain point. This was a safety precaution to prevent either fire or possibly poisonous fumes from spreading across the magical connection. Like all the other failsafes on the system, it could only be overridden on the Equestrian end, where the crystal was that powered the shut-down system.
In the cave on Mars, a pocket of methane hydrate thawed in a bubble within a larger block of permafrost. Unlike the prior trickles of methane, mostly captured by the soil and eaten by bacteria, this large, suddenly liberated bubble of gas erupted through the artificial soil, blowing open a vent hole about five centimeters wide and five meters deep.
The gas circulated in the air, joined by more methane given a route to freedom by the miniscule eruption, and gradually drifted towards the air intake of the life support box.
On the other end, the air crystal, which had warmed only a few degrees above room temperature, began to sputter with a fitful, flickering flame, popping again and again with each fresh ignition.
In moments the crystal reached the temperature marked as the danger point, and the failsafes kicked in.
In the life support building on Cape Friendship in Equestria, alarms went off.
In the cave on Mars, air circulation stopped, and the lights of the life support unit, the only light source in the cave at night, winked out.
The cave went still and silent, as still and silent as it had been for billions of years before the intruders came.
And, unsensed by the one creature who imagined she could hear it, I am here became I am in trouble.
Aw Christ, well, not good.
#SaveTheCave
Ohhh crap. Why, Mars? Why must you torture our adorable ponies?
8875585 Forty-four tons including landing stage, NOT fueled. Sixty-four tons fueled, and probably more since they're certainly going to try to slap more fuel onto it as they did in the book.
Are you accounting for delta-V losses to Mars gravity and (minimal) Mars atmospheric resistance?
Well, as long as it doesn't blow up, I believe it's salvageable. They still plant stuff in the hab, don't they? Equestria should, by now, have actually sane people watching those life support systems 24/7. A short "WHAT THE HELL HAPPENED TO THE CAVE?!?!" should be enough for our intrepid heroes to go there and try solving shit.
There's also the possibility of it going all to hell, but most likely it will be only a case of a very very sad Cherry Berry without cherries. Let's hope, that is.
Well, I've been waiting for this fic to either die off or reach a word count that I could spend more than an hour on. Now that we are at 200k +, best get reading!
"AMICITAS, THIS IS FRIENDSHIP. COME IN. OVER."
"FRIENDSHIP, THIS IS AMICITAS. OVER."
"AMICITAS, BE ADVISED. WE'VE MONITORED AN EMERGENCY SHUTDOWN OF LIFE SUPPORT IN THE CAVE. OVER. USE CAUTION."
I always get anxious when you start going into heavy detail about one of the safety systems. That said, this sounds much less problematic than I think I was expecting. I wasn't in the "It's gonna blow up" camp, but I was expecting the crops to either slowly wither away without anyone noticing, or become actually poisonous. With this, they should discover the problem pretty quickly and be able to resolve it. The cave is insulated after all.
Of course, that's all assuming that enough methane didn't leak out to make the cave immediately poisonous to our intrepid heroes.
That aside, I wonder how long until Watney remembers his death box battery?
Oh fuck...
Cherry Berry is going to be pissed.
And they all died.
Because Mars is an asshole and put methane hydrates there on purpose.
Imma blow it up, FOR REVENGE!!
8875669
Feel free to compare to your own result.
I did not account for martian atmosphere. Don't expect it to make that much difference? it near vacuum, by the time you pick up speed you should be above most of it.
I did account for gravity losses.
My numbers
Interactive draft version
Can anyone explain the last line?
8875739
Dragonfly belives that the cave is saying I am here.
Well, that was bad in that the life support link shut down, but good in that it shut down in a controlled manner and immediately alerted everypony at HQ that something was wrong with the farm.
A problem realized is a problem on its way to a solution.
8875731
I feel we will be introducing the ponies to something, world shattering.
https://www.youtube.com/watch?v=1LApZqpe5yQ
That'll take care of the revenge.
I wonder if Starlight would prefer the OT, PQT, or the NT.
8875736 Ok, these numbers in the spreadsheet look a little strange to me.
I don't know the effective thrust of either methane or ethyl alcohol (the two most likely products of the MAV's fuel plant- I don't think it ever says which it actually makes), so I'm taking your word for that.
Looking at the book now. The MAV's launch weight (both stages, capsule, crew and surface samples, but NOT descent stage) is apparently 12,600 kg plus a standard load of 19,397 kg of fuel and oxidizer; call it 32 tons. I'm guesstimating the descent stage, with struts, engines, fuel tanks, hydrogen tanks, fuel plant, and RTG, in the ballpark of twenty tons by itself. I'll go back and adjust the numbers I had Venkat give last chapter in a bit.
Apparently the first stage burns substantially longer than the second stage (backwards from what I've come to expect from Earth launches), so for approximately an 8 min. 15 sec. normal burn, at least five minutes of that is first stage. You've got a burn time of almost seventeen minutes for the first stage alone.
I'm not familiar enough with other terms (especially what I take to be rocket engine equivalents) to work with them, so I'm leaving further calculations to you.
Apparently the first stage normally has five engines, since in the book Watney removes one to save weight. It's possible the thing might have four engines with a tetrahedral arrangement, but I doubt it. NO WAY would NASA remove one of only three engines, not when it would imbalance the center of thrust.
"The air crystal went a bit farther, absorbing and sending air through one side of the crystal, returning it through the other side, allowing for air circulation and"
And?
We're going to get a plot twist:
'And they all died. The End'
Aden't we?
Well frak.
8874484
Most plants can tolerate quite a lot of methane.
Pockets of methane filling in spaces and forming empty bubbles like that would only be possible if there were sufficiently air-tight pockets. There aren't. The roots digging that deep would have been blocked by such seals.
Spitfire detected changes in air pressure too small for the Hab's atmospheric regulator to detect. We're probably talking 0.01% changes here for the atmospheric regulator to not detect it. A methane buildup sufficient to even bother anything will change the total air pressure quite a lot, because very small amounts of methane that aren't even a tenth of a percent of the gas mixture won't even affect humans much less the plant life.
...And this was rendered irrelevant by the latest update.
Sentence cuts off a few words too short.
Also, Mars farts in cave, results silent but deadly.
8875805 "... and for Santa Hooves to come down the chimney into the rocket every Christmas."
No, not really. I'll fix it.
8875821 Today's methane eruption was originally inside an underground block of ice, which was airtight until- (cave fart)- suddenly it wasn't.
The being most resiliant to danger would be Fireball. ?
Which isnt what you need in a high strength container with a combustible higher pressure gas mix inside?
Has the primary life support shut all the way down, breaking the connection, or jsut closed the flow and water etc parralel are still possible to keep active and maybe cross boot entangle?
Sliepnir 1 is going to have to try doing mid course ajustments to pinpoinbt land alaong the Great Escape line to Schaparelli, and it has the chance of ending up on the top of a core plug, sinking into a dune and falling over or landing on the far side of a hundred metre deep stress chasm?
You know when you get desperate when you deliberately make the spaccesuit explode to give that last metre per second delta V.
8875840
I can just imagine the reaction that would get.
Especially if he arrived with a bag of potatoes :)
8875691 "AMICITAS, THIS IS FRIENDSHIP. WHO FARTED?"
8875799
Columbia did it. Lost one of 3 engines 5 seconds after liftoff. Went to space anyway. Mission STS-93
Elon musk planned his BFR to land on 1 of 2 engines in case 1 failed (But changed his mind. It has 3 landing engines again now)
I did not calculate a big inclination change. That might make all the difference.
Also, the raptor engine was but a dream when the martian was written. He might have used less efficient engines. Or methane is not the fuel used. Or i messed up somewhere.
8875844 Sleipnir 2 (the one that didn't blow up or lose power) won't get to Mars until thirty-some days after Mark & Co. leave.
8875691 Something like that is obviously coming, yes, but it won't be "Amicitas calling Friendship." Friendship is the English word the ponies use for old Equestrian Amicitas, because that's as close as the translation spell can get.
(Remember the translation spell? Oh, the days of long ago, when men were real men, ponies were real ponies, and they conversed in Babelfish...)
8875772 I just realized something... Mars didn't put those methane hydrates there... THE AUTHOR DID!!!
*points finger accusingly at Kris* The culprit is... YOU!!! (DUN DUN DUUUUUUUN!) And your real identity is... *pulls of mask and all the ponies, Mark, Dragonfly, and Fireball gasp in shock* OLD MAN GREGORY?!
Kris/OMG snarls, "Dagnabbit!"
Alondro explains, "You see, OMG discovered there was a vein of Unobtanium running right below that cave where you all had your farm! And he knew how valuable the metal was for it total bullshit properties! He could make a fortune, take over Hasbro, and rewrite the show in his image!"
Kris/OMG, "And I woulda gotten away with it if it weren't fer you dang ponies and your Internet Troll!"
8875876
Recalculated with 2004 specific impulse estimations: Lost about 15% performance. That does tighten the delta-v budget a bit more.
is anyone else forgetting the Slephiner 1 probe? or was it 2?
Anyway, the probe with more food should be on its way to add more food packs to this journey, or is probe 1 being sent to the ship instead?
That is some questions I have.
8875689
always found the I will read until X word count to be really dumb. So young fault for being behind just because it’s not a certain word count. Eye roll
8875883 Yeah, well, it's the author's job to be a bastard to the characters of a story.
8875885 Again, by the time Sleipnir 2 arrives, the action will be over one way or the other. Hermes gets there over thirty days before Sleipnir 2's scheduled arrival.
8875846
"...and that's how Santa died. any questions?"
8875893
"What's the worst possible thing I can do to these people?" -- Lois McMaster Bujold on how she generates story ideas.
She has since added "...from which they can learn something." to the formulation. YMMV.
And so we reach the next major hurdle. Sleipnir’s looking awfully good right now, I bet.
Yeah Mark, let's talk about food. Like how yours is all dead.
8875948
not just dead, probably poisonous too
8875669
If this was a tabletop game, you would be the asshole DM.
Just saying.
Well.... buck....
That has got to be the most depressing way I've ever seen "Server state: DOWN" written... you're tugging at my feels, man!
8875669
right now i can feel every person of religion on that earth is on their knees peering to gods to save the ponies
So the life support crystals hate complex molecules? There goes my theory that the calorie problem would be solved just by rigging up one of the suits to spout out apple juice...
or cherry juice...
8875924 Since I am a research biologist who's watched a ton of sci-fi... no, I would never do the worst things I can think of to my characters. Not even non-existent beings deserve what I could do to them.
There's a reason I find most horror utterly boring. It pales in comparison to what I know is physically possible.
In fact, I had an idea for a horror pony fic that was so horrible, it made me feel queasy as I sat writing out the first full scene that came to mind. It involved a Cordyceps-like fungus and changelings and ponies being unfortunately more like changelings than was realized. It was gruesome and miserable. I decided, no, I'm not doing that.
8876071 The sugars in it would come out on fire, and the complex chemical flavor molecules chopped into lethal and volatile bits.
And hipsters in New York would make it into a drink that would sell for $20 a glass.
Does anyone have a picture of the pony ship?
8876188 And the baristas serving it would have to wear bomb disposal gear.
8876196 No, I've not asked anyone to draw it.
And I've just realized that I have a TON of writing to do tomorrow, because the next chapter has to be larger than the ~1500 word average. Because, y'know, methane, bacteria, no air, potential bomb, etc.
8875930
Not unless Kris/NASA can get S2 there a month or more sooner. With its preexisting design and preset flight path, presumably optimized for its starting conditions.
Oh! Craaaaaazy idea: mount the refueled S3 to Hermes, get around the Sun, launch S3 from between Earth and Mars orbits. Depends very much on the Slippery One III's mass, and how negatively that would impact Hermes's acceleration.