“Sorry I’m late,” Teddy said as he entered the room. He walked to his desk, set his briefcase on top of it, removed several folders, and stacked them tidily on one side of his blotter. As he turned to sit down, he looked around the room and froze. “Where’s Miss Park?” he asked.
“Still in SatCom,” Venkat replied. “It’s just past dawn at the Hab. She has to monitor the satellite footage for EVAs.”
“Understood,” Teddy nodded, taking his seat. Everyone else was present. Venkat propped up a wall as per his preference; Mitch sprawled on the couch, his eyes apparently closed but the earbud in his ear turned up so loud that Venkat could hear it buzzing from across the room. Bruce Ng had flown out from Pasadena, and based on the bags under his eyes he was wishing it was dawn here instead of 8:30 PM. And, of course, Annie had her eyes locked to her phone, sending one text after another, putting out media brush fires one at a time.
“Venkat, what’s Watney’s status?” Teddy asked.
“So far as we know, alive and well,” Venkat said. “No EVA yesterday, but Tall Boy went out to clean the solar panels, and the two Oranges and White Hen went to Site Epsilon and back, spending about five hours EVA. It’s two weeks now since we’ve seen White Boxy.”
“Do you think something’s happened to Boxy?”
“No way to know,” Venkat said, shrugging. “Mark hasn’t updated his message, so for the moment we’re just assuming some illness.”
“Any more clues about what the aliens are doing at Site Epsilon?” Teddy asked.
“No idea. But we do have one new bit of data. There’s a small temperature anomaly that shows up on the weather satellites’ infrared sensors. It shows up much better at night than in the daytime.”
“Temperature anomaly?” Annie asked.
“There’s a little spot on the northeastern edge of Site Epsilon that’s a lot warmer than anything else around it,” Venkat said. “In the last few infrared measurements of the site there’s a slight warm spot extending almost to the center of the site, but that one little spot is really warm. As much as twenty degrees above the baseline temperature at night.”
“Something to do with the crash site?” Teddy asked.
“Nope. The crash site is on the southeast edge. Wrong part of the site altogether.”
“Keep working the problem,” Teddy said. “Bruce, any progress on a supply mission?”
“It’s slow,” Bruce said. “We’ve been discussing strapping Delta-IXs onto the sides of a Red Falcon to try to get enough delta-V for a straight shot, but the engineering doesn’t work. Also, we need two to try it, and the only Delta-IX we have is Eagle Eye 3. It’ll be months before ULA can turn out another one.”
“What can we do with what we have?” Teddy pressed.
Bruce shook his head. “For the next two to three months? Nothing. If we launched Eagle Eye 3 to Mars tomorrow, its payload wouldn’t be much more than one box of crackers and a greeting card wishing him good luck. And the earliest that would get to him is Sol 332. If we add enough weight to make it worth the trip, the arrival date gets pushed clear back to Sol 613.
“But Space-X has promised three Red Falcons ready to fly in four months. In an ideal planetary alignment each Falcon could lift thirty-four thousand kilograms to Mars. But with the alignment we have four months from now, we’ll only get about one metric ton each. To feed Mark and his guests, plus a new radio and a couple of other things, we’ll need all three plus Eagle Eye 3. But they won’t arrive until Sol 578 at earliest.”
“By our best estimates Mark and his friends will all be dead by then,” Teddy pointed out.
“I know,” Bruce shrugged. “But I can’t move the planets, and I can’t change gravity. We can get a ship there in time with not enough food to hold out, or we can get enough food there too late for it to do any good.”
“Keep working the problem,” Teddy said. “Have you tried making the final stage lighter?”
“Well, I-“
Bruce was interrupted by Venkat’s phone ringing. Venkat pulled the phone out of his pocket, noticed the name on the screen, and accepted the call. “What is it, Mindy?” he asked. “We’re in a meeting… he is? That’s good, but is there a reason why this couldn’t wait? … Which protocol? … oooooooh, God. Ooooooooh, God. Don’t take any high-magnification photos of anything in that area, but keep watch on the Hab and the area south of there. I’ll be down there in half an hour.”
“What is it, Venkat?” Teddy asked as the director of Mars operations put his phone back in his pocket.
“Watney’s taken the rover south of the Hab,” Venkat said. “Mindy thinks he’s going to where Commander Lewis buried the RTG.”
“He what?” Mitch jumped up from the couch, eyes wide open.
“Oooh, Christ,” Bruce moaned.
“Are you sure about that?” Teddy asked.
“Wait a minute, hold on,” Annie said, looking up from her phone and waving a hand. “Remind me again, what the fuck is an RTG?”
“Radioisotope Thermoelectric Generator,” Venkat explained. “It’s what a MAV uses for power while making fuel. We use it because the MAV is too mission-critical to rely on solar power alone. Curiosity also had one, and each of the Viking landers had two.”
“Big whoop,” Annie said. “What’s so bad about it that you look like you’re having a coronary?”
“It’s a fifty pound box that contains a bunch of iridium pellets,” Venkat continued. “Each pellet contains a ball of plutonium-238.”
“Plutonium?” Now it was Annie’s turn to be shocked. “Fuck me! And you let astronauts dick around with that stuff?”
“It’s in iridium-covered pellets inside a graphite-lined case,” Venkat explained. “Both layers have to fail in order for there to be any danger.”
“But it’s almost certain death if both layers do fail,” Teddy pointed out. “Which is why mission protocol is to get the RTG at least four kilometers away from the Hab as soon as duties permit. Commander Lewis performed a solo EVA and did that on Sol 4.”
“But why send it up at all?” Annie said. “And why the fuck does Watney want the damn thing?”
“The RTG does two things,” Venkat said. “It produces one hundred watts of continuous power. That power is generated from heat caused by the plutonium’s natural decay. It’s not an actual reactor. Fifteen hundred watts of heat gets converted into one hundred watts of electricity. He probably wants it for one or the other.”
Bruce was typing on his laptop. “One hundred watts won’t buy Watney much extra distance per day on his trip,” he said. “We’re still assuming he’s modifying the rover for a long journey, right?”
“Right,” Venkat said. “Eventually Ares IV, but we hope not yet.”
“Let me get some people working the numbers on how much more distance he gets if he doesn’t have to run the heater in the rover,” Bruce said. “But just off the top of my head, I think it doubles his daily travel range. If he’s done the same math, then it makes sense.”
“But that’s what I don’t understand,” Venkat said. “Watney knows there’s nothing at Schiaparelli except the MAV. He can’t survive there. So why is he doing this now?”
“I’ll call in Dr. Shields,” Mitch said. “This is a psychological problem. She knows the crew better than any of us. If anyone can guess what’s in his head, it’s her.”
AMICITAS FLIGHT THREE – MISSION DAY 60
ARES III SOL 62
Cherry Berry began peeling off her space suit the instant Airlock 1’s inner doors opened into the Hab. “What is he THINKING?” she shouted in Equestrian to anyone who might care.
Starlight, who had been practicing typing on one of Mark’s spare computers, looked up. “He’s standing right behind- SPITFIRE!” She dropped off of her work stool and galloped through the stand of young potato plants towards the sweat-soaked commander. “Cherry, what happened to you?”
“Oh, I just popped back to the Badlands Hive for a few minutes,” Cherry said quietly. “At high noon in mid-summer. Only it wasn’t the Badlands, it was the inside of Mark’s bucking rover!”
Mark hadn’t unsuited. After a brief curious glance at his irate partner for Serious Two (whatever that meant), he walked over to where he kept his tools, selected the largest hammer from the kit, and grabbed a roll of grey tape. This done, he left Cherry in good hooves and stepped back into the airlock, closing it and beginning the depressurization cycle.
Spitfire, meanwhile, had given Cherry the once-over. “It only looks like a lot of lather,” she said. “Some water and a bit of salt and she’ll be fine.”
“How did you get so hot?” Starlight asked.
“You remember that box Mark told us about last night?” Cherry asked.
“Yes,” Spitfire nodded. “He told us it was extremely dangerous and that we absolutely were not allowed to touch it, move it, magic it, or eat it. We were all there, Cherry, of course we remember.”
“He told us it was warm,” Cherry said. “He didn’t tell us you could fry eggs on it!”
“Really?” Starlight asked. “It’s got a metal inside that’s only theoretical to pony science, I know that. But I didn’t know it got hot.”
“Mark had the heater off for the trip back,” Cherry said. “It took less than ten minutes, but in that time it got hot enough in the rover that I wanted to shave my fur off! And I have been to the Badlands in summer, so I know what I’m talking about!”
“Well, he did need heat,” Starlight pointed out reasonably.
“Nopony needs that much heat!” Cherry insisted. “Now if you’ll excuse me, I’ve got a date with the shower. A nice cooooold shower.” Ignoring the raised eyebrow this brought from Spitfire, the pink pilot pony stomped across the Hab to the decon shower… until she got to the potato plants, at which point she stepped as lightly as possible.
After that short trip with the alien, staying at base and tending plants definitely looked like the better option to her.
...its payload wouldn’t be much more than one box of crackers and a greeting card wishing him good luck....
Yeah, but right now I think he would contemplate homicide for a box of Burpee seeds.
8719754
H right. I forgot that.
Lol, cherrys reaction is GOLD.
And mankind looked upon the ponies of Equestria and said:
"Behold. The magic of the atom."
By my very rough, novice, and likely inaccurate calcs, that's just over 5,000 BTUs. Yeah, inside of the rover, that's hot.
What I want to know is if the dragon will eat it.
Fireball will love the new super-hot box. Boiling water hot-tub when?
Another fun chapter, as usual.
I really like Starlight's interest/total lack of concern for the plutonium Mark retrieved. Her saying it was a metal only theoretical to pony sciences in particular helps hammer home the different, divergent paths pony and human science has taken.
8719942
I think Mark was more worried about Dragonfly eating it.
Lead and Lead? I thought it was something like Zirconium Oxide or even Sapphire ceramic casing per pellet, or even a mixed oxide ceramic core with layers like a gob stopper? With blending and encapsulation, its amazing the toxicity of compounds that get permitted for food grade use.
Though if the first chunk gives off alphas, what do the daughter, decay chain give off, overall?
Really needs a lot of research on the energy converter, OTEC gets that 6% from a 30C differnce and I suspect the inside is alot hotter than that over the radiative outer surface.
Still need to see just how rectifiers work at thermal temps, such as photon sinks, given there is one version that works at optical frequencies, it must be possible to design them to work at lower energies, temperatures than 6000K equiv.
At least he aint doing like the Brazilian, Mexican scrap dealers and popping it open because the blue glow looks pretty.
After this trip though... they won't need the rtg for another 3.5 years... so burying it in garden would give them more growing area.
Digging a hole and place it in, then fill the hole with water. Warm water would rise up, and cold water would come back into the hole.
Hmm ... I'm kind of hoping Mark will end up taking Dragonfly with him on this trip.
Now he needs to cut out all the bits of the rover that keep entropy from ruining his road trip... so that the entropic death jar doesn't do the same thing in reverse!
8719646 The Amicitas life support is what provides air, water, and most of the heat for the cave farm.
Annie can be forgiven for being the Percival here, ie the 'dumb' one (not really) who needs an explanation so that the reader can also get one. She's the sensible choice, as the AN points out. Btw, thank you for putting time into those as well. They're an interesting read and they've added quite a bit to the experience of this fic.
I wonder if they're going to try and work out some way to communicate with each other during Mark's trip. My first reaction was Mark being nervous about leaving the crazy aliens alone in the hab then remembered that they've been living together for a solid two months already. They should have a pretty solid grasp of how human tech works and what they can and can't touch.
In other news, I'm also curious if they're using the extra space provided by the cave to spread out a bit and get some space from each other.
Yes the RTG appears the magic hotbox of death. There are some issues with your description, First off it is not a box it's more like a fat tube. Second, it has no lead in it the Plutonium is wrapped in Iridium and graphite then that's wrapped in carbon fiber. The video below gives a break down of the current gen NASA design.
https://www.youtube.com/watch?time_continue=33&v=4qkvoVRdoNgSo. Is the power thermocouple based? Not terribly efficient to get 100 watts out of 1500 watts heat. Still, would pulling current off of it mitigate some of the heat as well as extending the travel time of the transport? º›º
8720057
I dunno about a "Solid grasp of human tech" the most advanced thing we've seen so far is Dragonfly nicking Marks laptop to watch cartoons. Still if the hab breaks the cave is a good backup and it runs on magic so Starlight will likely be able to maintain it.
Radioisotope Therm
aloelectric Generator"Where’s MissPark?” he asked"
"Where’s Miss Park?” he asked"?
"I just popped back the Badlands Hive for a"
"I just popped back to the Badlands Hive for a"?
"After a brief curious glance at his irate partner for Serious Two (whatever that meant)"
Well, obviously, there are two of you, and you're supposed to be very serious. :)
So, do ponies have lower high-temperature tolerance than humans, here, since Mark seems to not understand the problem Cherry's having?
8720112
It's also possible that, in the original application, some of the waste heat wasn't waste but used directly for processes requiring it; for that, a direct supply of heat would be more efficient, and potentially have less that could break, than a heat->electricity->heat conversion.
If I was stated before in the comments I lost it, but who are the two oranges, the box and the hen, again? Tall boy is our drain, obviously, but I have no idea about the others.
And I still think Earth will freak out in the best way possible when they find out the life out there is pastel colored ponies.
8720170
White box is Starlight. She's been down for days from arcane weakness.
Hen is Spitfire, because she mother hen's over Starlight constantly.
That leaves Cherry and Dragonfly as the two oranges.
Okay I've been reading this story since like it was like 3 chapters in, but never had a fimfiction account so never commented, but it's finally made me get an account just to comment on this story. It's just that amazing.
I actually like the Earth based segments the best, wish there were more of those. One thing I feel like we're really missing from that though is we don't have their estimates of his odds of growing food. I mean they know he is trying to grow food, and they were going to have some botanists try to crunch the numbers to figure out how much food he could grow in the hab. So I'm curious what number they reached on how much he could extend his ration time with the food he could grow.
They probably also would have calculated the food the "guests" needed per day from the supplies that Mark was giving up and how long that would last them. Since his food supply would extend theirs by 27 days, and he was giving up 100 days of food they could then calculate how much food the guests are eating from that. Incidentally how was this figure reached if only 3 of them are eating and they eat equal amounts to him? Since that should have extended their food 33 days instead of 27.
Shouldn't NASA have detected via spectroscopy the huge amount of perchlorates that were dumped outside the cave?
Also I'm surprised the heat bloom is so small. Given there's something like 150 degree celsius difference between the hot water coming out and the extremely cold martian environment I expected it to be huge. I'm expecting they will determine they are building a base at some point as it continues to heat up to more habitable temperatures.
Extended math on heating
Though I notice you didn't account for the lighting enchant. Shouldn't they notice that the reflected light off the surface has declined quite noticeably if the crystals are gathering light from a larger area than their own surface? (As they were implied to in order to produce more light on the inside of the cave than is hitting them on the surface.) Also one of the other posters pointed out that the light collected by those lighting enchants would provide much more heating than even the RTG inside the cave. If we're assuming around 400 watts per square meter for martian sunlight over 600 square meters, that's about 240 kW of heating, minus the small amount converted to chemical energy by photosynthesis. Even if you figure only half that for 10 hours a day it's still 1200 kWh of heating. This is going to dwarf the RTG heating. Though depending on the volume of water the ESA life support can put out that could be higher. A 90 Celsius drop in water is going to be 105 Wh per liter, so if it's putting out 100 liters an hour could add up to 252 kWh a day. 500 liters an hour would be 1260 kWh a day. The solar heating is going to be a huge factor either way.
For mafic igneous rock we can guesstimate a thermal conductance of 4W/(m*K). ∆Q/∆t = −K*A*∆T/x. Now we set the left side of the equation as equal to our average heating throughout the day. Let's assume 2400 kWh for combined solar and water heating for a nice easy 100 kW heating steadily (roughly, the martian Sol being slightly different won't make much difference here). K I already gave. Area is tricky. We were told the cave they sealed off was 21 meters wide at the widest, 110 meters long, and a few meters high at the highest. An approximate oval shape gives a bottom area of 1814m. A 3 meter highest point half upper half ellipsoid with those same figures then gives 1986 square meters on the top. Total surface area estimate 3800 square meters.
Now strictly speaking the bottom I should do the semi-infinite math, but that's a pain in the ass. The top half is probably only 2 meters or so thick, so let's just go with a meter of rock on each side and the understanding this will be underestimating the insulative effect on the bottom.
Then it's just a matter of solving for delta T to see how much heat we can keep in.
100,000 W = -4 W/(m*K)*3800m^2*∆T/ 2m
∆T = 13.16 C. Still 37C freezing when starting at a balmy -50 Celsius average outside temperature.
Fortunately we can improve these numbers! Dry soil has a thermal conductivity of only 0.5 (and the soil below the plants will be very dry indeed).
100,000 W = (4 W/(m*K)*1986 m^2+.5*1814m^2)*∆T/ 2m
∆T=22.62 C. That gets us to -27.4C, which is cold, but getting there. What we really need at this point is to move up the solar energy from over 600 meters to the whole cave floor, which would double the total heating and get us to 45.24 C warmer than the outside, or about -4.76 C, which wouldn't be half bad. I mean that's still 23 Farenheit, but you could survive that with blankets and layered clothing. Plus it would be way warmer closer to the ground (if say you're having to sleep in there).
A layer of ice along the roof would also improve insulation as it has about half the thermal conductivity of rock, and the temperature is still below freezing anyway, but the ice would have to be impractically thick to have any real impact here.
Edit: Tldr; You can in fact get the cave barely habitable (23 Farenheit once lighting is extended over whole cave). Good job!
8720170
Cherry is orange leader (because she's always in front during EVA's) Dragonfly is orange random (she's a changeling) Starlight is white boxy (she usually is lugging a magic battery around) Spitfire is white hen (she's usually trying to keep Starlight from giving herself a stroke)
8720132
I mean that they've likely seen how to work most everything, given the forced proximity. I don't mean they understand how some of the stuff does what it does. Think of it as an equivalent to spending a couple months watching someone drive a car. You won't know how the motor works, but you can check the oil, fill the fuel tank and probably (even if not explicitly trained) drive it yourself.
And they better not render the hab uninhabitable. The potatoes are in there. Although this does bring up a rather important point: even if the hab does fail before rescue, they've got a back-up and won't need to make an emergency trip to get off planet. They'll be able to survive. In a CAVE! With a BOX of SCRAPS!
8720170
8720181
Specifically, Cherry is Orange Leader and Dragonfly is Orange Random
Lol. I really like the inscrutable aspect here of Watney from their perspective.
He just kind of does stuff from their pov.
Although I can see that letting some nasty things happen possibly. Still funny to me at the moment though.
8720225
Dragonfly is an engineer so she might be able to fix some things. (Or somehow cause the hab to blow up 5 times in a row because changeling) but even in her case she's mostly dealt with stuff that's woefully outdated and unsafe by NASA standards or runs off magic. They might be able to push the right buttons but actually fixing broken machinery that has no equestrian counterpart (they've had no need for oxygenators or water reclaimers) is not going to be easy to figure out.
8720112
8720167
Thermocouples generate electricity using heat flux. The higher the temperature difference from one side to the other, the more electricity produced. The up side: constant power for years, or even decades with waste heat that can be used to keep cold-sensitive equipment warm. The down side: heavy and inefficient (only 8% at the upper end). 100/1500 are not unreasonable. Lastly, due to the way they work, putting a load on the RTG would not affect the temperature in any significant way. It's possible he might get a little more mileage out of the rover, but that's getting into "is it worth possibly breaking beyond my ability to repair" territory. You're also going to run into "how?". I highly doubt that Mark has the requisite electrical splicing equipment.
8720269
That's what I mean about the car example. They know how to run the hab for day-to-day stuff and should have had a number of lessons on what not to touch. Leaving them alone runs only a minimal risk of something breaking because someone was poking around where they weren't supposed to. That doesn't discount stuff breaking on its own, but in that case it would break even if no one was there.
8720297
That's also assuming that a botanist thinks about thermocouples at all. They're not common, and at that point you've moved beyond basic electrical engineering and are moving into intermediate territory. If I remember correctly, the efficiency is also affected by what metals you have for either end of the device.
cant wait for the habs airlock to blow out. wonder how you will spin that. :P
Well we now know that the RTG is DEFINITELY the solution to the cave heating problem plop that sucker down in the cave and have something to circulate air and boom heat problem solved
8720372
There is always the chance that something changes to butterfly it away. Or at least preempt it.
8720297
Ah, thanks. I may not have thought things through thoroughly enough.
8720392
The RTG only puts out 1500 watts of heat, even the most conservative estimate for how much heat the solar lighting provides would give over 30x that amount of heating even after averaging out hours of daylight and darkness. So the RTG's heat isn't really that significant. The rover is just way better insulated and has under 1% the surface area of the cave.
8720394 If Starlight reacts fast enough, and has the magical energy stored, emergency shield across the breach.
8720394
naa. that was a technical fault from overuse. since there are more in there.. well.. more use.. more BOOM!M!!!AMLDSKAJDKJ
8720492
Eh people forget that the overuse was because he was going out to the rover 5 times a day through the same airlock to check the mail received through Pathfinder. He got pathfinder working Sol 97 and the airlock blew out Sol 119.
The airlock has got a lot more use cycles left in it.
I'm not even sure that they'll need to have him run out to the rover every time this go around either because if they wanted to they could use the wiring and radio from the Amicitas to set up a relay from the rover to the Hab by hooking into the exposed wiring where the original antenna tore off. They can probably kitbosh an analog conversion program for the hab computer, mail it to the rover, then use a usb stick to transfer it to the Hab computer to interpret the Amicitas radio.
Or get lazy and have someone sit in the rover and use the communicators in the Amicitas space suits to communicate with the other suits inside of the Hab. The Amicitas suit comms don't seem to care about the Hab's radiation shielding.
Awesome story dude!
I saw the movie so I can understand most of what's going on. Xd
Except when they talk about math or anything like that, goes over my head, as far as the moon. Lol
Which chapter is it they all get in a tesla roadster and go for a drive?
"It's just Watney being Watney."
"That isn't an explanation!"
"For him, it is."
8719931
At which point one of the ponies said, "That's not magic, that's just what oversized atoms normally do."
8720190 The heat is so small because it's only really just begun. Except for the areas right around where the air leaks were (especially the entrance), the cave is under quite a lot of rock, permafrost and soil.
Also, your math is kind of iffy considering the uncertain throughput of Starlight's sun crystals, but it also leaves out four 200-watt electric heaters and a constant circulation of air with the incoming air at a temperature of roughly 70 degrees F. Those should nudge your numbers up a bit. That's kind of vital, because 23 degrees F is hypothermia territory for ponies/humans and outright death for plants. The farm needs to be above freezing (40 F or higher) for it to work. And because magic, it is.
8720297 NASA insisted that all equipment be standardized- all hoses use the same couplings, all wiring harnesses use the same plugs, etc. Watney is able (apparently- the book elaborates no further than this) to connect the RTG inside the rover to the rover power system with no special procedures at all. That said, he does also have all sorts of spare wiring cable and electrical parts to make repairs or adaptations.
8720354 In the book Watney has master's degrees in both botany and mechanical engineering.
And then Dragonfly decides to try and feed off radiation... and that was how xenomorphs were REALLY created!
8720468
Wouldn’t that only buy a few seconds given the magicaly cost of such a thing
8720167
I’m asdumibg it that fur. It a natural insolator. Pinkie crossed the frozen north without even a shiver after all
8720768
unfortunately, they fudged the numbers, and overshot Mars; and the roadster is currently headed for the Asteroid Belt. but probably even before then, Solar Radiation will massively accelerate the aging process and the car will be scrap by the events of the Area missions.
8721001
Great. Now I'm picturing the chestburster scene only with an adorable changeling grub instead.
Someone needs to animate that.
8721055
orig00.deviantart.net/4881/f/2014/320/d/a/changeling_by_dan232323-d86lqge.jpg