MISSION LOG: 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.
...Never let Dragonfly, or any other Changeling, go near that cave. Hell, having one living in the hab is to close.
aaaand there's where murphy reared his ugly fuckin head
Oh god, that's not good.
On a related note: who wants to place bets on the perchlorates being teleported or moved, dropped too roughly and causing a massive explosion somewhere nearby. I wonder how NASA would react to that....
Alarms blaring, screaming, wailing and gnashing of teeth, methinks
Good and solidly scientific chapter though. It should be noted though that Mark knows that they're in a low magic environment and a military campaign were your most vital resource is super rare is... well... see WW2, German invasion of the USSR.
Every time Watney got optimistic in the novel like he had in the previous chapter, something blew up spectacularly in his face basically on the very next page. By that standard he got really lucky this time, since nothing actually blew up. Yet.
Featured box ho! Congrats!
Ok this is just some random person who knows nothing about true chemistry, but to me it sounds like they have a lot of burnable stuff in a cave which was full of micro-fractures?
How hard would it to use this newly found option to burn the cave fractures down? If it could be done in convenient manner.
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Alternatively, they can light a huge dangerous bonfire.
Nah, this was a good day.
Starlight learned things, there are plenty of opportunities for chemistry lessons, and if the pile of death manages to get moved, they have much better farming land.
"While the changelings first taped a lawn chair to a trash can of fireworks only about four years prior to the story"
Oh the early days of the CSP were hilarious!
The ponies faces (Spitfire's in particular) must've been hilarious when Mark just scooped them up and hauled ass to the rover. xD
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Dude has hit the featured box damn near every time he releases a new chapter. It's awesome!
Ah-hahahaha!
Oh, I love it when ponies use magic to solve an impossible problem just to put everyone in three times the danger.
Ammonium perchlorate and one of the biggest industrial disasters in the USA. https://www.youtube.com/watch?v=_KuGizBjDXo
I wonder how salty Matt will be when he realizes that the Equestrians basically developed all of humanity's rocket science(about two centuries worth of explosions) within the span of half a decade?
They have a limitless supply of water. Shame it can't be dumped in the perchlorates. Even if the water would not just freeze-dry itself in the martian atmosphere , the ammount needed would take so long to properly soak that chances are it would result in it getting triggered by the few tons of water pressing down on it.
Maybe Starlight could use what charge is left to teleport it away as far as she can? Although I can see the teleportation causing enough blunt trauma to ignite the percholates, so it would be better if she teleported it somewhere that can safely be exploded.
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(Starlight) "and that's the story of Equestria's space program!"
(Watney) ...
(Starlight) "What did you think?"
(Watney)...
(Starlight) "You ok...?"
(Watney)*wordlessly gets up. Blows self out of airlock to save self from more elaborate, insane, and most likely painful death due to pony insanity*
8688136 Dumping large amounts of water on large amounts of perchlorate was explicitly disrecommended by one of my sources, since perchlorate absorption of water is an exothermic reaction.
inside (may be an error by Mark)
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From what I can tell (as someone who knows very little about chemistry), the problem is that outside of magic it cannot be moved and even then it might ignite due to friction. They cannot handle it otherwise bad things will happen to their suits. Same applies to their shovels. The second problem is that it's pretty much an unstable ticking time bomb that could annihilate the cave, the gems and the surrounding area. And the third problem is the sheer quantity of it, if it did ignite in an uncontrolled manner, and as I said before that cave would be destroyed.
I think that's why it is such a massive problem in Mark's eyes. But I may have gotten wrong, and if I have I am sorry.
8687417 Pollinators just doesn't have an edge to it... you need to sound menacing!
I mean, look:
"WE ARE... THE REPLICATORS! We shall REPLICATE all over your FACE!! BWAH HA HA HA!"
vs.
"Uhm, we're... the... Pollinators... if that's ok.. we're like... Breezies... please don't hurt us!
And the Murphy God strikes again.
Slowly, but surely, they drew their plans against us.
Well, thats one way to launch something off Mars.
Drop activated Verne cannon.
Can Starlight just levitate that pile away from the cave? (maybe, in parts and after diluting it with sand?)
I wonder how she was planning to get rid of it in the first place.
One mighty horn!
All things considered, this isn't quite the bomb Watney thinks it is.
For all the nasty chemical reaction presented by the perchlorates, the blast potential will be limited by the surface area exposed to any fuel sources.
Strictly speaking. The middle of the ball can't explode because it can't touch fuel.
So the real threat is that this thing first starts an unstoppable fire. Then proceeds to create its own thermals to start scattering the dust in the thin martian atmosphere.
THEN you have either an explosive hazard similar to a poor thermobaric weapon, or a rain of flaming powder.
But it's unlikely to be like PEPCON.
Oh, the cave is not just a bomb. It's a *fragmentation* bomb, with gemstones for frags.
Starlight, this is what we refer to as "Scaling." First you do the experiment on ten grams. Then a kilogram. Then a ton. Then a whole cave. That way "Oops" is defined as "pop" instead of "BOOM!!"
You can't wet the pile of perchlorate, since at best you would create a lot of heat and send it right back into the soil there. At worst you would have a big hot pile of slowly burning perchlorate as it reacts with the ground under it and whatever it can adsorb out of the atmosphere. I don't think magnesium perchlorate can break water molecules up but it is very fond of being in a solution and as such will generate a whole lot of heat.
Remember, fires require both oxidizer (the perchlorate here, normally atmospheric oxygen) and fuel. Here fuel is the lacking point, and perchlorate isn't explosive so it won't randomly reduce itself to hot nitrogen gas. The stories of exploding benches is more of a sudden, rapid fire than an explosion, although to most people that is a difference without a distinction since the general effect is about the same. It's probably starting to burn what ever it can out of the soil under it immediately, but that's mostly rock so there isn't much that low ion perchlorates can attack. Something with a bigger, uglier cation on it could very well burn stone, however.
That having been said, a pile of perchlorate will probably corrode and/or burn just about any tool they have at hand to try to remove it. And if the pile/puddle of death just so happened to fall onto something it could burn, it would burn so rapidly that it would functionally explode. And I'm sure it's just dying to burn through both the suits and the human/pony inside more or less on contact. So just levitate it up and away. Far away. You don't want a storm to blow that shit back towards anything important.
Well it could be worse. It could have somehow become Chlorine Triflouride...or Azidoazide azide...and it somehow didn't immediately combust from incidental solar radiation or magic proximity or anything...
I'd be thinking; "keep the cave at Mars atmospheric pressure, if the airlock is already in place: rig it to be all open, take a little bit of the death powder at a time and throw it to a safe distance on the surface."
Was going to posit; "would the perchlorates even be able to burn?", before remembering "they're used in rocket engines, they'd need to burn in a vacuum to do that, so on Mars isn't a stretch."
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C2N14, thankfully, is not something nature just coughs up. And it's too bad Watney doesn't have SciShow episodes to show Starlight.
Hnnng! Ok, I want to see this. Someone get on it. Starlight in a space suit with puppy dog eyes, wagging her tail.
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Right, I assumed that Spike tried to send a scroll, it burned do ash, and that was it. Based on the rased eyebrow, I can only assume that either:
1. The spell failed completely and soot+ash came from the spell collapsing, not from anything burnt perse
2. You can't send unburnable stuff with dragonfire. Which would make sense but I don't think is an established rule anywhere?
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Is the perchlorate going to become an important part in rocket fuel?
Hey atlest it is not Hexanitrohexaazaisowurtzitane. (I too know of Things I won't work with)
For those curious about how explosive this stuff is, check youtube for PEPCON explosion in Henderson NV.
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Ah yes, the classic PEPCON explosion. Good old ammonium perchlorate. I still go back and watch that video sometimes, just for kicks. Definitely not a substance I want to be anywhere close to -- the biggest boom I've ever done was a hydrogen-filled party balloon.
I'd like to see the explosion just to see the reaction from the observers in orbit.
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Or even FOOF. That stuff's seriously not fun to deal with.
Well, good news is, this isn't PEPCON. Magnesium perchlorate looks pretty safe (reactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water) compared to ammonium perchlorate (reactivity code 2: Undergoes violent chemical change at elevated temperatures and pressures, reacts violently with water, or may form explosive mixtures with water). It's an oxidizer, but it sits on non-flammable dirt, in a freezing cave. If it did not explode after magical extraction immediately, then in all likelihood it won't explode at all. It may start an unquenchable fire of doom that will melt a hole in the floor, if the soil has some chemical that can enter an exothermic reaction. But it won't explode unless someone has a really bright idea to seal the cave entrance making it a giant shell casing.
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Love that line!
As for the perchlorates, I don't think Mark should worry as much as he is; it's been nearly twenty years since my last chemistry class but if I remember right the chemical reaches like those halt at the freezing point....
...and Mars is -55C so he shouldn't have a problem. Don't get me wrong, there are reactions that happen that cold and cooler, but I don't think perchlorates do.
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Not a bad list, but it needs didsufler-dioxide on it...now that's scary!
If the powdery ball of death goes boom and damages NASA's equipment, does it count as a foreign power opening fire on the US in international waters? I remember something about movie-version Watney technically being a space pirate.
"Houston, we are under attack by space pony pirates."
Well, at least the low temperatures should retard the reaction. Somewhat. Kind of.
Yeah, best to use telekinesis. I'd say have Dragonfly use everyone's love of staying alive and unexploded to fuel a telekinetic extraction, but that would mean putting her near the boompile. That is what we call a bad idea.
12 grams of impure potassium chloride.
Now turn that into kilo's of it and it's bigger, scarier, nastier brothers. It might not go boom but that's a road flare that NASA won't miss.
8688379 Ah yes, Diflorine Dioxide a.k.a FOOF, which pretty much the last sound you hear if you have a quantity of the stuff and even look at it funny. Seriously, Even stored at -160 K it decomposes at a rate of about 4% a day. This means it's shelf life at room temperature is NOPE, it doesn't have a shelf life. It reacts violently with just about everything, even at 100 K below zero.
8688303 Not if Watney can avoid it.
8688396 8688417 Under normal circumstances you'd almost certainly be right, I think. Certainly the cold temperatures ought to trump anything else.
But spoiler alert: this planet is out to get Mark Watney. And there's always a boom tomorrow. (Well, maybe not literally tomorrow, but...)
8688486 Yep. This is what potassium perchlorate decays into under heat, this plus oxygen. And, after that, into more oxygen and chlorine gas, among a number of other delightful death sauces depending on the environment.
EDIT Correction: KClO3 decays into potassium chlorate, not chloride, at least at first.
EDIT2: The video says ammonium perchlorate, which thank Me isn't in this story. Is this the vid you meant to embed?
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Into potassium perchlorate and chloride without catalyst (KClO3 is potassium chlorate):
4 KClO3 → 3 KClO4 + KCl
KClO4 → KCl + 2 O2
wiki
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Stop it! You're giving the changeling ideas!
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i actually know Murphy personally...we arnt friends. and its all due to a slight misunderstanding between us. well, more like between me and her father...long story...
My take on this is that Watney has a pile of stuff that would give him all sorts of headaches trying to move it with his tools, but is not immediately dangerous. Ammonium perchlorate is explosive because the ammonium ion is a fuel and the perchlorate is an oxidizer. The Mg+2 and K+ are already oxidized, you need to supply some other fuel to get so much as a fire, much less an explosion.
Letting it get mixed with a fuel would be bad and could cause a fire, but it seems to be sitting quietly amongst a bunch of sand. Letting it soak up water from the air in the cave would be messy and bad, whenever they get around to filling the cave with air, but as long as they can get it out of the cave, it's a pile of toxic sludge which can presumably be removed with telekinesis. It's not nearly as heavy as the ship, after all.