• Published 2nd Jan 2018
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The Maretian - Kris Overstreet

Mark Watney is stranded- the only human on Mars. But he's not alone- five astronauts from a magical kingdom are shipwrecked with him.

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Sol 37


I am fucked, and I’m gonna die, and it’s all the ponies’ fault!

Okay, that’s not fair. It’s not all their fault. It’s not even all Starlight’s fault, even if the whole mess was her idea. I’d assumed that she knew as much chemistry as I did, and so I never pressed her on her brilliant plan to clean the cave of perchlorates. If I had, we wouldn’t be piled in the rover with my foot to the floor retreating back to the Hab, or as I like to call it, “safe blast radius.”

And the hell of it is, we have to go back. Site Epsilon doesn’t have another cave. Even if all else fails, we need the quartz and other gems for Fireball to eat. Which means, oh archaeologist of the distant future, if you find this record inside an ancient rover sitting next to a collapsed cave, it’s because we died trying to clean up the largest spill of pure anhydrous perchlorates in recorded history. The least I can do is tell you why.

Today, after cleaning off the solar cells, I drove Starlight and Spitfire out to the cave. Starlight brought with her one of their magic batteries. The gauge showed almost two-thirds full, which is pretty impressive considering she lifted their entire ship on just about twenty percent. (Hint: if I screw up and trigger a pony-human war, Earth’s best hope is to surrender immediately. If all unicorns are like Starlight we’d never stand a chance. All hail our adorable pony overlords! Let's just hope they don't kill us all by ACCIDENT!)

I had no idea what the ponies had planned. But considering that for almost a week we’d been watering the Hab from an infinite supply of water, plus the other amazing things pony magic can do, I had just sort of imagined that Starlight would raise one mighty hoof and just command all the perchlorate begone. And Starlight saw that it was good, and said it was good, and it was good, etc.

Well… no.

Based on the conversation Starlight and I had after the fact, magic has definite rules and limits. And one of the big ones is, magic can’t create or destroy matter or energy from absolute nothing. In theory enough magic power can be converted into matter, but no single pony is powerful enough for that. Even just moving matter around is pretty costly.

So Starlight’s brilliant idea was to make a magic spell that specifically sought the two compounds that make up 99% of the perchlorates in the soil- potassium perchlorate and magnesium perchlorate. The magic would pull the perchlorates out of the soil and put them someplace where it would be easy to remove them. That would turn a nearly impossible act into merely a lot of hard physical labor.

All of this sounds good, right? Wrong! And it’s because of how perchlorates work. How is it possible that this unicorn, obviously the smartest out of the group of aliens who are all presumably the best and brightest their world has to offer, doesn’t know anything about perchlorates? They’re used in solid rocket fuel, for fuck’s sake!

The perchlorate ion is made of one chlorine atom and four oxygen atoms in a fragile covalent bond. It’s an efficient oxidizer. It’ll make things burn very, very quick and hot.

The problem comes when you want to stop it burning. You can’t. The protocol for a perchlorate fire is to dump sand on it and try to scatter the fire, then wait for it to burn out on its own.

To make things even worse, the perchlorate ion bonds with other ions to form various acids and salts. This means, in addition to oxidizing stuff while burning, the perchlorate dissolves and burns stuff as its (usually metal) ion goes flying off to do other shit.

Now, this isn’t so bad when the perchlorates are diluted with water or other substances- at least not the light perchlorates. Perchlorates of heavy metals are on every chemist’s Nope Fucking Nope list. And the rare organic perchlorates are considered to be bad ideas by any scientist who hopes to go to their grave with all ten fingers still attached.

But Starlight’s spell didn’t say “grab the perchlorates and whatever’s right around them.” Oh no. It said, “Do you swear to fetch the perchlorates, all the perchlorates, and nothing but the perchlorates? I do!”

So Starlight set up on the entrance side of the first big hall, where we’re planning to have our farm, and began sending out pulse after pulse of magic light in strobes down the cave, so far as I know clear to the back. And every pulse brought back fragments of white or yellow powder, which accumulated in a ball floating in midair. And that ball grew… and grew… and kept right on growing.

I tried to stop her, but Starlight was so wrapped up in the spell she didn’t really see me. Spitfire stopped me from shaking her, probably for the same reason you’re not supposed to wake a sleepwalker. And having seen what happens when a spell fails (see the infamous Bullet Bead of Sol 23), I came to my senses and left her alone, watching that giant ball of pure firestarting poison continue to build.

When Starlight shut off her spell there was still juice in her battery. She didn’t even fall over. In fact, she turned to me and looked up at me like a dog I once had. See, Mark? I did the neat trick! Now where’s my Milk-Bone?

And while she was doing that, the enormous pile of perchlorate dust flopped to the ground. It was a short trip, but it took a while for the ball to become more of a mound. When it settled the pile was maybe three meters tall and as wide as the chamber itself.

I don’t think one sand bucket is going to be enough.

Now, if it was just potassium perchlorate, I woudn’t panic. Potassium perchlorate is well-behaved so long as you don’t get above two hundred and fifty degrees Centigrade. It’s mildly toxic and mildly corrosive, but ordinary precautions will handle it.

But forty percent of that ball of death was magnesium perchlorate. Potsassium perchlorate has only one perchlorate ion. Magnesium perchlorate has two, plus that hungry Mg++ ion. On rare occasions magnesium perchlorate has been known to spontaneously combust, or to ignite by friction, just from touching certain substances. The safety rules for magnesium perchlorate tell you to keep it away from acids, all flammable organic compounds, and aluminum.

Problem: my sample shovels are aluminum.

Problem: so are large portions of my space suit.

Problem: all my sample bins are plastic, i. e. organic. (For dilute magnesium perchlorate in Mars soil this would be perfectly safe. All the plastics and carbon composites on the mission are rated non-flammable. For 100% pure perchlorates, though, all bets are off.)

Problem: large portions of all our space suits are also organic. (Fireproof, but pure magnesium perchlorate…)

And big, gigantic, horrible, no-good problem: if the magnesium perchlorate finds something to ignite it, the resulting fire will be more than hot enough to decompose the potassium perchlorate that makes up the other sixty percent of that damn pile.

So I grabbed a pony under each arm (thank you 0.4g Mars!) and fled for the rover, where Starlight and I had what the diplomats call “a frank and open exchange of ideas.”

We can’t give up on the cave. Somehow we have to think of a safe way to get all that crap out without actually touching it. But I’m sure as hell not sticking around while I think about it, not when there’s even a remote chance that the Martian soil itself- chock full of iron oxide, potassium, phosphorus- might be enough to set that crap off.

The gem cave is now a bomb.

Author's Note:

Wrote 3600 words today. The buffer is now either six or seven chapters, depending on what I do about three days from now.

I indulged myself here, because, "I am fucked, and I'm gonna die!" was too glorious a line to not allow Watney to deliver again. So this was set up so that a similar threat to Hydrogenville would confront Watney on Sol 37, the same day he discovers it in the book. (And yes, in the book Watney blatantly taunts Murphy by saying, quote, "Things are finally going my way." Which is why he did it last chapter in this story.)

Also, today is the day Mark is once and for all disabused of the notion that the ponies are "more advanced aliens." Starlight made a serious error in judgment that might get them killed immediately, and she's definitely put the castaways' long-term survival in jeopardy.

That said, I'm almost certainly overplaying the explosive dangers of magnesium perchlorate for this sequence. I'm not a chemical expert; I'm learning from warning instructions I find on websites as I search. Magnesium perchlorate is sold as a brand-name industrial dehydrating agent by the barrel. Its fire hazard doesn't rate above 1 or 2 on the scale-of-five used by the warning signs. Potassium perchlorate is even more stable.

But I did read numerous warnings of fire hazard and even spontaneous explosions involving magnesium perchlorate- including a bench which had been soaked with perchlorates for a long time exploding when somebody struck it. I may be exaggerating things, but I'm not making this up out of whole cloth. The warnings repeatedly say "avoid friction", "don't mix with anything flammable," and, "A lot more things are flammable than you might think."

And these warnings are mostly to do with impure perchlorates- the industry standard for commercial use appears to be 83% pure. Starlight, our lovable little obsessive insecure recovering sociopath, has created a pile of 100% pure perchlorate salts, 60% potassium perchlorate and 40% magnesium perchlorate randomly mixed, measurable in tons- and one hell of a lot of tons. Even as stable as these two particular perchlorates are compared to some of their more ill-advised cousins (seriously, who thought mercury perchlorate or friggin' fluorine perchlorate were good ideas?), I'm sure any chemist confronted with a pile of them twice as tall as he was and as wide as a trailer house would find their vocabulary temporarily restricted to, "Oh, shit."

So yes, Mark said some very mean words to Starlight. Can you blame him?

Next time the ponies will make very sure Mark is clued in on the plan before execution.

Why Starlight didn't know about perchlorates' other properties besides toxicity will be explained next chapter. For now, suffice to say that Mark is the end product of over a century of humanity's experiences with rocket flight and rocket accidents, while the changelings first taped a lawn chair to a trash can of fireworks only about four years prior to the story.

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