Good morning, log! Today is a busy day for me, because I’m the only one in the Hab with a working space suit! Dragonfly says the suits are still curing after yesterday’s patching work, so none of the pony crew is going outside today. So, in addition to brushing off the solar panels, I get to do a lot of driving today!

Today’s chores: dump the RTG back in its hole; make a circuit of the weather stations and see which ones can be brought back online; go to the farm and check on things there; and bring back some quartz for Fireball, because he’s running low.

Quite a shopping list I have. Eggs, butter, plutonium, quartz.

Luckily I don’t have to worry about NASA giving me new orders today. Pathfinder is still working through the upload backlog, thanks to the photo session getting pushed back while the ponies had their makeover at Spa Watney. (I don’t blame them. I am, after all, the most popular and exclusive spa host on the whole planet.) So until the upload is completed I’m off NASA’s leash.

I gotta say, it feels nice. There’s a world of difference (see what I did there?) between involuntarily cut off from communications and voluntarily cut off. Earth is still there if I want or need them, but for the time being they can’t touch me for some stupid questions about alien rhizomes or percentages of light converted to heat when transmitted through a magic crystal.

Just got around to reading Dr. Shields’ email. Basically she says she told Venkat off when she found out he ignored her advice. She’s put in for time on the chat to talk with Dragonfly to find out her views on doctor-client privilege and trust issues. And she says that if Venkat or anybody else, even Teddy Sanders, tries this shit again, she’ll resign, call a press conference, and blow the whistle so hard I’ll be able to hear it here without Pathfinder.

Irene Shields might be a head-shrink, but she’s all right.

“Watney’s a dead man.”

The words hit Venkat’s ears at the same time a large pile of printouts, neatly held together by a pair of alligator clips, thudded onto his desk. The bearer of this ill tidings, Sue Douglass, was the head of JSC’s Astromaterials Research labs, which among other things included planetary geology. She was the one who determined which research labs did or didn’t get the priceless mineral samples from Ares I and II, and who would do the same for the quick-stow samples from Ares III’s truncated mission.

“Good morning, Sue,” Venkat replied pleasantly. “Good to see you’re on time for your appointment, which I don't remember you making. I trust my secretary made you comfortable while you waited?”

“I said, Watney is a dead man,” Sue replied. “And so are those adorable colorful aliens who are on the front pages of every paper in the world today.”

“I heard you,” Venkat said patiently. “Would you mind explaining why?”

Sue picked her massive report back up, flipped through several pages, and held it open for Venkat to view. It was a photograph of Watney’s cave farm taken from just inside the impossibly installed alien airlock. What appeared to be half the glittering crystals in the ceiling glowed with a bright light, fully illuminating the dark green plants in elongated rows on the dirt below. More crystals coated the walls, with several running completely from floor to ceiling at odd angles- including one that plunged right into the heart of the cultivated area.

“It’s an impressive sight,” Venkat admitted. “So?”

“So?” Sue asked sarcastically. “So it’s a lava tube. It has to be. It’s not even the largest or longest lava tube we’ve spotted on Mars, though how it got attached to a volcano that small will make somebody’s doctoral thesis someday. Obviously it was flooded with water for hundreds of thousands, maybe millions of years. Hot, mineral-rich water, to be exact. And those minerals deposited in all the vugs left behind when the first lava flows cooled, first forming a raw quartz overlay, then the crystals we’re seeing here.”

“If you say so,” Venkat shrugged. “I’m physics, not geology.”

“You’re the top Mars man in NASA,” Sue replied. “Which means you know why we knew lava tubes existed on Mars before now.”

“Remind me.”

“Because we’ve seen them. From orbit.” Sue flipped four pages in the report, then jabbed a finger down at a photo of Tharsis taken by a satellite. “And the reason we can see them from orbit is that they collapsed. Lava tubes always collapse, Venkat. They’re infamous for it. The material is weak and brittle and porous as all hell. That’s how you get geodes in them in the first place.”

Venkat grabbed the report and began flipping through the pages at random. “Are you telling me the roof is going to come in on Mark’s farm?” he asked.

“Nooooooo, no,” Sue said. “That would be too easy. That would be what might happen if the cave had been left alone.” She took the report back from Venkat and flipped to the appropriate page, a page full of equations Venkat recognized. “But that cave is full of one full atmosphere of air pressure. And according to Watney’s log, it’s only definitely airtight at the airlock end and at the far end- where the old tube meets what I’d guess it its old magma chamber.

“So do the math with me, Venkat. We know the material making up the cave walls is porous. The only reason we can guess for there not being any leaks right now is a layer of permafrost and compacted regolith on top of the cave. But the more that system heats up, the more unstable those layers will become. Eventually there will be a leak. And you know what happens then?”

“No. What?”

“The Hab airlock happens, that’s what!” Sue jabbed a finger at the equations again. “Except this time it’s at least fifty times as much air and a much tinier hole… at first.” She turned the page to more equations. “The air will leave through the initial breach at the speed of sound- three hundred sixty meters per second at least, maybe faster. The force of the air will rapidly erode the sides of the breach, causing cracks, faults, and blowouts.

“And then, once the air pressure on both sides is equalized, whatever’s left around the breach will be unsupported by the thick cushion of air it had before. The faults will continue to propagate, and the ceiling will cave in, probably in huge chunks.

“In short,” Sue said, closing the report and slapping it onto Venkat’s desk, “the cave will first blow out, and then cave in. And incidentally, anyone inside at the time will be killed by tornado-scale winds, decompression, or falling rock. Have your pick!” She took a breath, sighed, and added, “And even if they all live, there is absolutely no way they could ever repair the farm.There wouldn’t be a hole in the roof, Venkat. There would just be. No. Roof.”

Venkat nodded. “All right, I believe you,” he said. “But the two questions I have are: what can we do about it, and how long do they have before it happens?”

Sue shrugged. “It could happen tomorrow,” she said. “Or it could happen after Ares 3B arrives. We don’t know enough about the composition of the soil above the cave, or for that matter in and below the cave. We have Watney’s analysis,” she said, nudging the report, “but he geared that analysis towards the immediate task of growing crops in what he found.”

“Do you want him to take new samples?”

“Hell, no!” Sue shouted. “The soil in the cave’s contaminated now, and the last thing in the world we want now is anything disturbing the soil on top of the cave. No,” she said. “What we want, ideally, is for that alien to do whatever she did to seal the ends of the cave for the entire cave. Make the geode absolutely airtight. Do that, and the risk of blowout is eliminated so long as they don’t crack the outer layer of quartz in their mining operations.”

Venkat blinked. “Mining operations?” he asked.

Sue rolled her eyes. “Venkat, how much sleep have you been getting?” she asked. “And have you been reading your own chat logs?”

“Not enough,” Venkat admitted. “What did I miss?”

“God knows,” Sue said with feeling, “but in this case you missed two things. The aliens use gemstones and crystals like quartz for their technology. And the dragon eats gems. Without the quartz crystals he has no food supply at all.”

“Okay,” Venkat said, making some notes on a scratch pad. “I’ll talk to Mark about it tomorrow and see if it’s feasible. What about interim precautions?”

“If possible, lower the air pressure to ten PSI inside the cave,” Sue said. “That’s equivalent to the air pressure in La Paz, Bolivia, and they can grow crops there. And monitor the temperature and keep it as low as cultivation will permit. The lower the temperature and the less the pressure differential between inside and outside the cave, the more time we have before the system literally collapses. Also, tell them to stay the hell away from any of the crystals that go completely across the geode. Up and down, side to side, whatever, leave them the hell alone.

“And above all, tell them to be gentle when cutting crystals off the walls. Don’t bend, push, twist, whatever. Straight cut or nothing. Shear forces on the outer walls of the geode are the worst thing that could happen to that setup.”

“Okay,” Venkat nodded. “Can we test any of this in the lab?”

Sue nodded, “I have some models we can put in the partial-pressure chamber and simulate, yes. We’ve already done computer models, but they’re based on incomplete data.”

“Get a proposal on my desk by tomorrow morning,” Venkat said. “You’ll have funding no later than the end of next week, so start lining up your personnel and materials needs now.” He tapped Sue’s report and added, “Also forward this to Director Sanders and email a copy to Commander Lewis on Hermes. Teddy needs to know, and Lewis was the geology specialist for Ares III. She might have some input on this.”

“Right.” Sue nodded, and then, having said her piece, she turned to leave.

“Wait a moment,” Venkat said. “Wouldn’t you be interested to know what I’ve been reading, that has me forgetting Mars chat logs and other reports?”

He swiveled his computer screen so that Sue could see it. The title of the document showing read: INTRODUCTION TO MAGIC THEORY AND ITS RELATION TO PHYSICAL LAWS – STARLIGHT GLIMMER, ASTRONAUT.

“You would not believe,” Venkat said, unable to keep the hunger out of his voice, “how eager I am to make sense of this. And I have several thousand scientists from every branch of NASA except possibly yours demanding the chance to do so.

“And they all want access yesterday.” Venkat sighed. “I’m going to chat with Starlight tomorrow, so this is my homework. I need to know enough,” he said, tapping the screen, “to get to the point where my questions rise to the level of stupid.”

Author's Notes:

Yeah. I went back to the cave being a lava tube. Vugs is vugs.

This chapter is to drive home the point: any air leak above the microscopic level won't be bad, it'll be catastrophic. That cave is a bomb now a thousand times more potentially lethal than the perchlorate pile ever could be. And it all comes down to differential air pressure.

I did a ton of writing today. My 3,700 Scribblefest entry lost 700 words, then gained 2400 through rewriting. And then, after I posted it, I wrote another 2000 words for Maretian to keep the 1-chapter buffer alive. (Also, the last two paragraphs of Watney's log here were supposed to go on the end of yesterday's chapter, so I had to rework that to fit here.)

Anyway, my Scribblefest entry, a highly improbable and silly bit about what Rarity is willing to do for her family, is here:

For Love of Love of the Game (or, Rarity Makes an Athletic Supporter)

Note: Rarity does very little sewing in this story.

Enjoy!