AMICITAS FLIGHT THREE – MISSION DAY 53
ARES III SOL 56
“Aa, aa, aa,” Mark said, “Hand, an, apple.”
The crew members of Amicitas chanted along with Mark for the sixth day in a row. Usually this ritual came right after an episode or two of The Electric Company, after dinner, but today Mark wanted to do it right after breakfast. Dragonfly wondered what caused the change.
“Eh, eh, eh,” Mark said, leading the next line. “Lend, men, English.”
She could sense Mark’s eagerness for something or other, but Dragonfly was pretty sure it wasn’t eagerness for more English lessons.
“Iih, iih, iih. Hit, tin, pimple. Aah, aah, aah. Top, common, ostrich. Uh. Uh. Uh. Punt, under, cup.”
Mark had explained the ritual by saying that, when he’d been taught another language in school, one of his teachers had drilled them on pronunciation with a daily ritual like this.
“Ay, ay, ay. Made, quaint, mistake. Ee, ee, ee. Heed, sweet, fever.”
None of them knew what three-quarters of the example words meant, but the ponies enjoyed chanting together. Dragonfly enjoyed the enjoyment. And Fireball… didn’t object.
“Eye, eye, eye. Tie, file, crocodile. Oh, oh, oh. Row, over, floor. Yuu, yuu, yuu. Usually, rule, ukulele.”
Fireball didn’t object to much anymore. Dragonfly knew he wanted to, that his guilt trip over almost killing everyone was fading. She could feel him swallowing blunt remarks about this or that thing all the time. In fact, right now, she knew he wanted to say something vulgar. Then he looked at Mark’s earnest face, felt a bit of shame, and chanted a little louder.
“Ur, ur, ur. Hurt, her, bird. Ar, ar, ar. Mark, target, pirates.”
That last word didn’t make sense, but it still made Mark laugh a little inside, so Dragonfly enjoyed the emotional tidbit and didn’t ask for the explanation.
“Or, or, or. More, pork, story. Oi, oi, oi. Foil, oink, spoiled. Ow, ow, ow. Bow, owl, couch. Aw, aw, aw. Raw, maul, awed, Uh, uh, uh. Book, took, nook. Ooo, ooo, ooh. Screw, blue, cockatoo!”
As the last line ended in pony laughter, Dragonfly could only think, How do they get by with so few vowels?
With the introduction over, Mark took out a whiteboard- now a slightly gray board, since even dry-erase markers leave a residue over time. He wrote the word Sols on top of it and then, on the left end, wrote the word 6. “We met on Sol 6,” he said. He then wrote Sol 1412 on the far right end. “Ares IV comes on Sol fourteen-twelve.”
Everyone nodded, including Dragonfly. This had been explained to them before.
“Ares IV is not coming here,” Mark said carefully. This got a couple of blank looks, and he changed it to, “Not. Come. Here.” He wrote a long word, a strange-looking one even in Mark’s alphabet. Schiaparelli. “Come Schiaparelli Basin.” He turned his little thin computer so the screen faced the ponies, showing a satellite map of Mars. “We here,” he said, pointing to a flat, low-lying area in the top center of the map. “Ares IV come here.” He pointed to a very large crater well east and south of where he’d pointed before.
“How many kay?” Starlight asked.
“How far is it?” Mark corrected her, being careful to enunciate clearly. “Thirty-two hundred kilometers.” He drew a long line on the whiteboard, labeling the left end 0 and the right end 3200. “This is what the rover can do,” he added, and made a little mark just barely to the right of the 0, adding the number 35 to it. He pointed to the enormous difference between the two and finished, “Too far to walk.”
Dragonfly could sense that he meant the last line as a joke, but none of the others, herself included, found it funny. Not only was Mark’s ride home not coming for four years, but he’d have to journey halfway across Equestria to meet them. On this planet. The prospects, even for a changeling, were appalling.
“So I need,” Mark continued, once he figured out no smiles were coming, “to change the rover to go farther.” He paused, then wrote several words on the board, reading them aloud. “Change- to make different. Modify- to change something else on purpose.”
Starlight raised a hoof. “Purpose?”
Mark tapped his head. “Intent. Plan. Mean to do it. Not accident.”
Starlight nodded, lowered her hoof, and let Mark proceed.
“Also,” Mark said. He drew a little rocket ship. “Ares IV has six crew.” He drew six little stick Marks. “Six come down. Six go up.” He added a seventh stick-Mark. “Maybe seven. NASA,” he pointed to the swoosh patch on his shoulder, “NASA smart, figure something out. But twelve?” He drew a stick-dragon and four stick ponies, then crossed out all of them plus the seventh stick-Mark. Shaking his head, he said, “Can’t work. People get left behind.”
Now Dragonfly felt real anger rising in Fireball. The dragon leaned forward from his sitting position. “Leave us here?” he rumbled.
Mark, to his credit, didn’t blink. “No,” he said firmly, looking Fireball straight in the eyes. “When we go, all go. To stay here is to die. And nobody dies.”
Dragonfly almost stomped her hooves in pony-style applause. Mark meant every word- she could feel it. There was no joke, no brag, nothing but firm resolve in him.
“But NASA doesn’t know.., um, does not know we are here,” Mark said, forcing himself to slow his speech back down. “We need to tell them, six people here, need rescue. With years to plan, they think of way to get us all home.”
“But you no talk home,” Cherry Berry pointed out.
“I can’t talk with home,” Mark restated correctly, “yes, that is true. The radio,” he drew an antenna with lines radiating from its tip, “was broken on Sol 6. I can’t fix it.” He pointed to Schiaparelli Basin again. “Radio here works now, but there is no Hab there. No food, no cave, no farm. If we go now, we die.”
Starlight raised her hoof again. “Why radio there, if no one can live there?” she asked.
Mark drew a tall triangular object on little legs. “M. A. V.,” he said, and wrote out the words: “Mars, Ascent, Vehicle. Ascent means going up. Vehicle is a thing that carries people, like a car or-“ he almost pronounced the pony word correctly- “Amicitas.”
“M. A. V.” Starlight said, and the others, including Dragonfly, repeated it after her.
“M. A. V. makes its own fuel,” Mark continued. “But it takes time.” He wrote 500 Sols next to the MAV. “So it comes before anything else- er…” Anything else had been a phrase too far for everypony except Dragonfly, and Mark saw it in their faces. “It comes here first, makes fuel, then everything else comes. People come last of all.”
“So no radio here,” Starlight said, pointing to the soil floor. “Radio there, can’t use. So what do?”
Mark clicked a button on his computer, and several spots lit up on the map. “Other radios on Mars,” he said. “Maybe fix one of them. But I have to get to them first.” He set aside the first whiteboard, which was rather full now, and pulled out a second, drawing a very poor sketch of one of his rovers on top of it. “So modify rover now, test it, see it work, then go get radio.”
He smiled at the others and added, “Today we work on plan to do that- all of you and me. Together.”
Dragonfly looked at the numbers on the whiteboard, her mind entirely focused on the problem. She’d always had an un-changeling-like interest in making things work, and this problem was a lot more interesting than designing a self-deploying parachute or a functional space toilet (both of which she’d done). It wasn’t as much fun as pulling seven G’s during a hard re-entry, but she always felt happy and proud of herself when the job was done.
“Rover battery has nine thousand watt-hours,” Mark said. “Don’t ask how much a watt-hour is. Not important.”
The others shrugged and moved on. Dragonfly disagreed- the conversion from Mark power units to pony power units would be important in the future- but for now she realized explaining the conversion would distract from the goal. Since only Mark parts would be used on the rover, only Mark measurements were needed for now.
“NASA made the rover-“
“Made?” Fireball asked.
Dragonfly forced herself not to groan. They’d had the verb conjugation for “make” two days ago. She’d paid attention, because “make such-and-so” was one of the biggest contributors to the larva-talk problem.
“I make today, I made yesterday,” Mark explained. When Fireball nodded and leaned back, he went on, “NASA made the rover to go thirty-five kilometers on one charge. Five hour planned EVA, eight hour at most. Recharge at Hab.”
Charge was a word that had come up when discussing the emergency mana batteries. Dragonfly and Starlight knew it, but the changeling hadn’t known whether or not the others did until she saw them nod understanding.
“If I leave the Hab, I have to take something with me to charge the battery,” Mark continued. “The solar panels-“ Mark had to draw a couple of them, since the phrase wasn’t familiar to the ponies yet- “can be taken from the Hab and used to power… to recharge the rover.”He pointed to the rover. “Problem: can’t fit the panels inside the rover. Need space… need room inside for food, water, potty.”
Everyone else made a face. Potty was a word they all knew far too well. They had grown used to the stench from the compost bin, but nobody liked it.
“Put up on… er…” Cherry Berry reached a forehoof up to pat the top of her own head. “Put here up on rover,” she said.
“Put them on the roof?” Mark asked, pointing to the top of the rover drawing as he said the new word. “Okay, we’ll use the rope for that.”
“Charge while… er… charge while Bo-Luke?” Spitfire struggled.
“Driving,” Mark said gently. “No, can’t charge while driving. Need too many panels. Have to stop, spread like outside Hab, wait.”
Dragonfly reached over to Mark and grabbed the marker in her fetlock. She scribbled the equation 800 / 35. “You say the radio is eight hundred kilometers, yes?” she said slowly, being careful of her pronunciation.
“The closest radio, yes,” Mark said. He held out two hands, bringing them progressively closer together as he added, “Close, closer, closest.”
Dragonfly finished the math; twenty-two and six-sevenths. She scratched that out and wrote 23 instead. “Twenty-three days there, twenty-three back,” she said. “Too slow.”
“Yep- I mean yes, too slow,” Mark nodded. Need to go farther each sol. Need more power.”
“Glue solar panel to outside rover?” Dragonfly suggested.
Mark’s face twisted. “I’d rather not… I mean no,” he said. “I have glue, but it doesn’t come off.” His hands mad a motion of sticking two things together.
Dragonfly made a screwdriver motion with her hoof.
“Definitely no screws or bolts,” Mark insisted.
“But you need more power,” Dragonfly insisted. “Where can you get power?”
“Other rover?” Starlight suggested.
“Yes!” Mark said, pointing at Starlight. “I can take,” he mimed taking something in both hands, “the battery from Rover One.” He scratched out the 9000 on the whiteboard and wrote above it, in smaller numbers, 18,000.
Voila! thought Dragonfly. (Voila, she had heard, was Prench for, “I’m done, now pay me.”) “So now you go… um… two-times… the, er… length?” Her voice faltered, stumbling across words she hadn’t picked up yet.
“Double the distance,” Mark nodded. “Distance is length for a place instead of a thing. The distance from the Hab to the cave is ten kilometers.” He then held up one finger after another, saying, “Single… double… triple.”
The ponies, Dragonfly and Fireball all nodded.
“So, if I use all that power to drive…” Mark did the math on the whiteboard: 18000 / 200 = 180 / 2 = 90 km. “Two hundred watts per kilometer. Ninety kilometers a day,” he said. He sighed, shook his head, and continued, “But I can’t do that.”
“Why can’t?” Cherry Berry asked.
“Rover uses power for other things too,” Mark said. “Lights. Fan.” He made a little whirring sound in his throat, twirling his finger in a circle. “And heater. Especially heater. Heater uses four hundred watts.” More math on the whiteboard:
400 X 24.66 = 4 X 2466 = 9864.
18000 – 9864 = 8136
8136 / 200 = 40.68 km
Dragonfly cocked her head in confusion. "Near thirty-five kilometers again!” she protested.
Mark nodded. “The heater doesn’t run when I’m not in the rover,” he said. “But if I leave the Hab, I’ll… I will be in the rover all the time. So the heater has to run all the time.”
“But thirty-five kilometers is no good!” Dragonfly insisted. “What do?”
Mark shrugged. “I don’t know,” he said simply. “Magic? You have ideas?” He tapped his head to remind the ponies what ideas were.
Light flickered in the general direction of Fireball. The dragon, with the first smug expression Dragonfly could remember on him since the gunk went splat, had forced two little flames through his nostrils. For a moment he almost looked like one of the skinny dragons from the lands of the Qi Lin… well, more so than usual, Dragonfly admitted.
Mark’s eyes widened. “Huh,” he said. “Maybe that works.”
“You’re going on a road trip, Fireball,” Spitfire giggled in Equestrian.
It was worth a shot, Dragonfly thought. But she also remembered: dragons dislike the cold even more than ponies. That suggested they weren’t particularly good at warming up the air around them. But on the other hoof, Fireball was volunteering for something and coming up with ideas again- and this one wasn’t likely to get anyling killed.
But there had to be some better way. Maybe suit air could be used to heat the rover? For that matter, would one suit be enough to supply breathable air for two people in the rover cabin?
“Okay, we’ll try that,” Mark said. “We stay close to the Hab until we’re sure it all works. Now, let’s figure out… er… let’s plan how to put the second battery on the rover.”
“Glue?”
Mark gave Dragonfly an annoyed look. “No glue.” Then he paused… “Well, maybe glue. But I hope we find a better idea.”
The planning went into details. The second battery would be a pain, since it was too large for the airlock or the luggage rack. Dragonfly suggested various means of just attaching it to the side of the rover, all of which Mark rejected… until she suggested tying it on with rope. That produced the solution.
Mark had a supply of spare canvas for his base if the existing dome sprung a leak. He also had a supply of glue to hold it together. Put the two together, and you got saddlebags for the rover. The battery would ride in one side, and a bunch of rocks would be counterweight in the other side. The bags could be taken off after the trip, so the second battery wouldn’t be permanently attached to Rover Two.
Other things were discussed. Starlight Glimmer suggested navigation aids, particularly navigating using the sun and Mars’s moons. A slightly smaller sample bin was picked to be Mark’s honey bucket- one with a very secure airtight lid. Another bin was picked for Fireball’s rations for the trip, and another to be filled with enough water for the journey.
It was well past lunchtime by the time the basic plans were completed. Everyone ate their ration and then went to their afternoon chores happy. They had worked together. They had helped.
Except Dragonfly, who watched Mark drawing up plans for the canvas saddlebags on a whiteboard. He wasn’t feeling accomplished or satisfied, not in the same way. She thought he felt… smug.
In fact, the way he felt reminded Dragonfly of the queen just as some particular scheme of hers was paying off big-time. But what scheme? All he did was get us all to talk about figuring out…
… stuff where he came up with most of the answers.
Huh. He didn’t need our help for this, did he?
Dragonfly saw it all in a single flash. He’d taken his own planning time and turned it into an extra-long language lesson. He just brought us in to give us something to do. To give us practice in English. He had most of it worked out already.
Dragonfly stifled a grin. I like Mark, she thought. He thinks like a changeling.
8713133
Apollo 13 had two problems didn't it? One of the engines wouldn't fire properly during ascent or something.
8713185 Depends on how you define problem. I count four. First, an engine failure on ascent that was compensated for by a longer burn to orbit. Second, the O2 tank explosion. Third, the filter mismatch between CM and LM systems (yet another example of Not Invented Here at work). Fourth, outgassing from the LM's cooling system produced a trajectory drift that required a correction burn halfway back to Earth, at a point where nobody knew if the LM descent engine would still function.
8713191
Good chapter. Everything was explained in the context of the characters rather being directly told to the audience.
Always the best way to do it.
So... no playing around with expended nuclear generators this time around. I'll count that as a win.
just a prediction here but when the time comes for them to be saved, both Earths NASA Program and Equestria's Changeling Space Program will arrive at Mars at the same times
8713191
I suppose malfunction was the word I was looking for.
8713199
It's not just that. Consider that in the original work the rover's insulation had to be torn out to avoid the inside of the rover heating up too much. With all 6 crew, Mark figures he'd need both rovers. No need to worry about the Oxygenator or water reclaimer with the ESA suits, so both rovers could be used (granted, probably Cherry Berry or Spitfire would be trained as the driver for the other rover). Thus, no modifications making one of the rovers uninhabitable, and really, would you trust the RTG around Dragonfly, Starlight Glimmer, or Fireball?
8713218
My prediction is that the earth folks show up, and the equestrians have to pick up their stranded from earth.
I would take "you think like a changeling," as a compliment, as it implies cleverness and deviousness.
What a very nice way of demonstrating that an advanced and well trained learning intelligence needs as little as three examples to register something new. Activation. It doesnt match existing database. Synchronisation. The pattern is looked for subsequently to the occlusion of all other information for a period of time. Confirmation. The pattern is stored in active database as a new and unique entity that can be used for subsequent processing and analysis.
Also. Magic Rule Of Three.
Problem 5. All three LM fuel cells had a design where there was a gas pocket in which hydrogen and oxygen gas could collect and mix. One of them exploded, ruptured on the way back from the Moon. According to a later book of the story that I read a few years back. So it could be a totally different description. They wernt meant to run for an extended period of time so it wasnt considered a time based problem.
Loss of two main lifeforms from the Hab is going to cut into the magic battery recharging time, give Starlight somethings different to measure. Fireball is going to be in an even worse magical enviroment, is going to be the Vitamin C problem?
8713258
Mark can't makes the necessary sounds for Equestrian. They'd rather all learn his language than suffer through his butchered Equestrian which is apparently painful to listen to.
8713185 But it didn't blow the ship up. It was a minor failure more than compensated for due to the redundancy of the engine's power output.
Looking at it from a story perspective, real life made quite a brilliant dramatic move there, adding in the 'accident' the crew could shrug off as the only result of 'unlucky 13', thus preparing a bit of irony when the major disaster occurs.
Sometimes life is stranger than fiction, sometimes it's just better at storytelling overall.
Depending on how the battery was initially placed relative to CoM, wouldn't it be more efficient to balance the secondary battery with the primary? rather than using rocks?
Also, consider adding a Sail to the Rover. Wind power. electric motors can be used as a generator, build a windmill preferably vertically mounted...
Too bad Perchlorates are too dangerous to use as a fuel source for a fuel turbine...
8713247
Read Changling space program. Dragonfly is an anomaly in her competence. The rest first tried building a space capsule out of a cardboard box and their first "rocket" was a trashcan full of fireworks.
Dragonfly is far becoming my favorite in this story. Devious little bug. Still hope Mark digs up the nuke for heat though. Fireball and Mark stuck in a rover won't end well I think.
8713247
Are you sure about that? Changelings in this series have a pretty serious "What the hell were you thinking" trait.
8713348
I think it's alright, since she compared him to Chrysalis. She's pretty smart in this one, even if she is a bit volatile.
so how are the ponies gonna take to the solution for heating being the radioisotope thermoelectric generator being installed in the rover? that has to be done... i doubt starlight would like it and I honestly think it was a necessary part of the story also I think using fireball for heat would not go well as small room plus fire usually equals something(or somepony) burning to ashes
8713247
Remember when Mark described the Amicitas as being built like a tank?
That design philosphy is the end product of the changelings' presence in and around vehicles meant to explode in controlled fashion and fall at many kilometers per second.
8713504
I think he could explain it easily enough.
"This stays near us, we stay warm. This breaks near us, we die."
8713218
That would result in a human crew seeing a faster than light dimension hoping vessel come to rescue tiny pastel horses to take them back to their magical world. I dunno about you, but I'd ask what they were smoking and if they had any for me yet.
8713353
First of all Read the Book ^^.
It's definitely better.
On another note what I really HATED for the movie was that Commander Lewis takes the place of EVA Specialist Beck in getting Mark.
It's so FU*KING unnecessary, unprofessional, it REALLY devalue the character of Lewis as a commander, whose job is to COORDINATE the rest of the team [and drill rocks.] So what does she do? Take the one who is SPECIFICALLY trained to do EVAs recovery and go herself putting EVERYTHING in jeopardy for a whim.
Couldn't they send electric energy from Equestria through the teleport crystal in the suit? Also they could use pegasi magic to lighten the rover or even fly with it for some time.
"ComeSchiaparelliBasin."
"Come Schiaparelli Basin."?
"Dragonflyreached"
"Dragonfly reached"?
"You say the radio is eight hundred kilometers, yes?"
I'm not seeing where he did; I don't remember it from the first time I read that section and didn't find it going back looking for it. Am I missing something, or is it not there? Or did she just read it off the map and call that him saying it?
"Voila, she had heard, was Prench for, “I’m done, now pay me.”"
:D
Not sure I follow the math with the rover. So thirty-five kilometers is the rated range, with the heater and everything needed for normal operation, for one charge of one battery unit, 9000 watt-hours. Maximum designed operation time was eight hours, so call that 1125 watt-hours per hour (so the power consumption of the rover is 1125 W while in use). Doubling the battery capacity and assuming no other changes would give seventy kilometers in sixteen hours on a full charge. When Watney tries to double the distance, though, he instead divides 18000 by 200, and I'm not sure where the latter number came from, or why he tries to do that. That might the the power consumption used for propulsion alone, but why focus on that here when, as far as I can see, he was taking everything into account before, and going from that would be a simple doubling? Then there's the math after that taking the heater into account, which suggests that the rover's range on one battery unit should be only about twenty kilometers. So... what's going on here?
(Oh, and I'm guessing that, while he's speaking conversationally, in "Heater uses four hundred watts of power an hour.", he means it uses four hundred watt-hours (1.44 MJ) per hour (for a power of 400 W)?)
(Also, I get 800/35~=22.857, with 35*(23+(1/7))=810. And while I'm there, I don't think "800/35" counts as an equation by itself, but that seems minor; it could just be Dragonfly being imprecise.)
"dragons dislike the cold even more than ponies. That suggests they aren’t particularly good at warming up the air around them."
"dragons disliked the cold even more than ponies. That suggested they weren't particularly good at warming up the air around them."?
"rocks would be counterweight in the other"
"rocks would be counterweights in the other"?
Can Equestria send heated air through the suit?
8713653
Probably not directly, but Mark has hydrogen fuel cells for energy storage. Pure hydrogen and oxygen could probably go through (separate) teleportation crystals.
His fuel cells might not be easily refuelable, though.
Here's a language lesson Mark can give the ponies:
"A rough-coated, dough-faced, thoughtful ploughman strode through the streets of
Scarborough; after falling into a slough, he coughed and hiccoughed."
8713667
I'm guessing, "200" is supposed to be watt-hours per kilometer driven? ( [ {9000wh/5h = 1800w} - 400w = 1400w] / 7km/h = 200wh/km) It's not explicitly spelled out, though.
And yeah, there's some fuzzy math in there; presumably Watney oversimplifying for the ponies. Any time when he's charging, the heater shouldn't be counted against the battery -- it'll be pulling from the solar panels. Let's say he gets ~10.66h/sol useful charging time (for the sake of round numbers later...). That means he'll need 14h*400w=5600wh for the heater, leaving 14400wh -- which would give him a 72km/sol range (not accounting for other parasitic power drains...).
This, of course, assumes he's not supply constrained. Running some ballpark numbers, it looks like he'll need ~14 panels to fully recharge the batteries every day, assuming little margin for error. How many panels can he take if the ponies are still using the hab? It's a concern...
8713930
"I'm guessing, "200" is supposed to be watt-hours per kilometer driven? ( [ {9000wh/5h = 1800w} - 400w = 1400w] / 7km/h = 200wh/km) It's not explicitly spelled out, though."
Maybe...
Are you going by the five hour planned EVA time in that math, instead of the eight hour planned maximum?
"And yeah, there's some fuzzy math in there; presumably Watney oversimplifying for the ponies. "
Not all of it was done by Mark, though, and 800/35=23+(1/7), for instance, was done by Dragonfly and explicitly rounded to 24; why have a hidden change to 23+(1/7) from ~22.857 and then follow it with an explicit round to a third number?
"Any time when he's charging, the heater shouldn't be counted against the battery"
Oh, I hadn't thought about running the heater during the charging time; thanks. As you say, though, and as I agreed with soon after you started me thinking about it, that's a matter for charging time, not time running once charged.
"(not accounting for other parasitic power drains...).
This, of course, assumes he's not supply constrained."
Right; we are having to make some simplifying assumptions, still.
"Running some ballpark numbers, it looks like he'll need ~14 panels to fully recharge the batteries every day"
Where did you get power output figures for the panels? My apologies if I'm just forgetting something.
8713231 Very good points! And on a side note, regardless of Fireball, having that many bodies in a small place might allow you to have the normal heater and only need to use it for short stints at a time.
Though... personally a part of me wants the RTG to turn up at some point anyway, if only for the shenanigans of Mark trying to explain what it is, how dangerous it is and their reactions when they finally recognise it. I mean, Kerbal space program has RTGs so the Changeling Space program will either have it (or some less dangerous magical equivalent) some time in the future of their story. Then again maybe just having them recognise radioactivity and the Humans can and do use something so potentially dangerous as a power supply would be amusing too.
Makes me wonder if any other aliens have conceived of literal nuclear rockets or if they would consider us all insane...
Sorry, seems I've rambled off onto a bit of a tangent.
Tearing down the language barrier one planning session at a time. Now, let's just hope Fireball actually works as a space heater. I'm honestly not sure whether I'd rather have him or the radioisotope generator.
8713667 8713930 8713952 One of the hazards of rewriting a previously existing infodump scene is that sometimes you leave out bits and think they're still there for others to read.
The book says 200 watts per kilometer- it doesn't say watt-hours, it says watts, but I'm going by watt-hours.
The fuzzy math was me dividing 800 by 35 in my head and forgetting to carry a 1.
The exact distance to various sources of radio, including the closest, was off-screen in a scene break that vanished when I C&P'd the chapter into FimFiction.
What's going on with the rover math all around is this: the rover was intended for design maximums of thirty-five kilometers and/or eight hours of operation, and mission protocols of twenty kilometers and five hours for safety margin. The rover systems shut down when the crew aren't inside. But on the rover trip there will be crew inside almost all the time, except for EVAs to swap batteries, deploy solar panels, pick up solar panels, etc. So the non-travel power draws become a much larger issue and have to be either eliminated or budgeted around.
And it's definitely NOT true that the heater is free during recharge time. It might not be draining the battery, but it slows the battery's recharge time.
8713979 The interior of the Rover is repeatedly referred to as being about the same size as a van. Imagine cramming six people, plus all the food and water six people will need for fifty days, plus a bucket (or three) for potty requirements... and, well actually that's excruciatingly damn crowded already, so let's just stop at that and say that there are reasons why Mark's never had more than three people in a rover at a time over and above NASA-drilled mission protocols.
Can fireball regulate how much heat he puts out while he's asleep? Cause I assume he's going to need to sleep here and there during their Martian Oregon trail playthrough.
8714100
"And it's definitely NOT true that the heater is free during recharge time. It might not be draining the battery, but it slows the battery's recharge time."
That would fall under the "supply constrained" heading. Also:
8713952
"Where did you get power output figures for the panels? My apologies if I'm just forgetting something."
Assumptions:
Therefore:
2m^2 * 590w/m^2 * 25% * 2/3 * 8h = ~1573wh/day/panel
14 panels gets you 22000wh, minus 10h of heat (4000wh), for a full charge of 18000wh.
Fuzzy numbers, of course. Geography effects this; as does weather, usage, and a whole host of ephemera. But I'd consider 14 a hard minimum. Anything less directly impacts travel efficiency. As it is, assuming the dragon is an effective space heater, he should be good for nearly 90km/sol, for a ~18 sol round trip.
---[Edit]---
8714184
If they run the heater while it's charging, that's a solid 10 hours of sleep per sol, right there.
8714198 Those numbers are pretty close to what's in the book.
The solar panels are just under 11% efficient. They're on stackable stands that put them at a fixed 14 degree tilt to maximize efficiency during the period of the mission (Martian summer, northern hemisphere). Watney estimates insolation at between 500 to 700 watts per square meter as opposed to 1400+ on Earth. It's currently summer where he is, but northern hemisphere summer on Mars is when Mars is at its farthest from the sun. So 500-550 is a safe estimate. Panel usage is as close to 100% as makes no odds (and this is a significant plot point much later in the book).
Watney plans to drive pre-dawn and park during daylight. He estimates thirteen hours of useful sun- in short, almost the entire time the sun is up.
However, since 200 watts/km is ideal conditions, ninety kilometers a day wouldn't happen even if the motors were the only electrical draw. Watney knows this, which is why he's going to test his mods before he makes the trip. But driving and heating are the only draws Weir gives numbers for in the book, and the other minor draws (lights, computer, air circulation, etc.) are left to handle themselves.
When I read the book myself, the only thing about Weir's handling of this that rang warning bells in my head was the 13 hours of charge time. That seemed excessively optimistic, considering that there are limits to twilight driving and time lost to setting up and picking up the panels.
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Ahh, okay, thanks. :)
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And thanks.
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"When I read the book myself, the only thing about Weir's handling of this that rang warning bells in my head was the 13 hours of charge time. That seemed excessively optimistic, considering that there are limits to twilight driving and time lost to setting up and picking up the panels."
Wouldn't really matter. The dawn/dusk hour are so far into diminishing returns as to be not worth thinking about. You're talking about an hour during which he'd offset less than half of the heating budget for said hour.
It's that middle 10 hours which are his butter zone. Cover that, and he's golden.
Launch tomorrow....
Hopefully it succeeds. Ponies need a car.
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Its probably going to miss mars but it would be funny if they ran over the licence plate or something, just for the lols.
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I was joking. Its orbit won't intersect with Mars... wrong time of year... they're showing they could hit mars... if it was the right time of year, by having it go in the correct orbit to intercept.... except Mars won't be there to greet it.
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I know, it just would be funny if the car exploded in space somehow, and the parts went everywhere.
8714981 That wasn't an Equestrian linguistics thing. That was someone who doesn't have the English word of "double," but has the concept of "double," trying to prompt teacher for the word.
One of the things I've toyed with is seeing how few words you could pare English down to and still be comprehensible. For one thing, every single curse, profanity, maledicta, etc. could be dumped and replaced with an emotion word, usually, "ANGRY!"
And on the way, Fireball becomes curious about how hyoomans taste. He discovers they are crunchy and taste good with ketchup.
Mark learned to hard way never to meddle in the affairs of dragons. (You reached a Bad End. Retry? Y/N?)
The vowel exercise, for me, simultaneously was adorable and went on too long. The rest of the chapter, though, was plain adorable. Mark being smug, Dragonfly liking him for it and comparing him to Chrysalis, and lots of other little moments too.
The notion of the rover being given saddle bags, and how that could only have come from ponies, is so sweet
Is there any way they can shift the existing rover battery into the other saddle bag, evening out the weight with something they have to carry anyway rather than a pointless load of rocks? That'd leave more space inside for other stuff.
Clever Girl...
8717496 The vowel exercise was me making a point about the absurd number of vowel sounds in my native language. And, of course, because magic, the ponies have about half again as many more, which can only be rendered as "angry/panicky horse noises". :)
The thing about vowel sounds you point out is really interesting. As an Spanish myself, I now understand why my pronunciation of english differs that much from the real deal and why I find certain words confusing to pronunce. (I mean, some words are spelled similar and have totally different pronunciations)