Chapter 3 #2
In high school, I played a lot of Dungeons and Dragons.
(You may not have guessed this botanist/mechanical engineer was a bit of a nerd in high school, but indeed I was.) In the game I played a cleric.
One of the magic spells I could cast was “Create Water.” I always thought it was a really stupid spell, and I never used it.
Boy, what I wouldn’t give to be able to do that in real life right now.
Anyway. That’s a problem for tomorrow.
For tonight, I have to get back to Three’s Company . I stopped last night in the middle of the episode where Mr. Roper saw something and took it out of context.
LOG ENTRY: SOL 30
I have an idiotically dangerous plan for getting the water I need.
And boy, do I mean dangerous . But I don’t have much choice.
I’m out of ideas and I’m due for another dirt-doubling in a few days.
When I do the final doubling, I’ll be doubling on to all that new soil I’ve brought in.
If I don’t wet it first, it’ll just die.
There isn’t a lot of water here on Mars. There’s ice at the poles, but they’re too far away. If I want water, I’ll have to make it from scratch. Fortunately, I know the recipe: Take hydrogen. Add oxygen. Burn.
Let’s take them one at a time. I’ll start with oxygen.
I have a fair bit of O 2 reserves, but not enough to make 250 liters of water.
Two high-pressure tanks at one end of the Hab are my entire supply (plus the air in the Hab of course).
They each contain 25 liters of liquid O 2 .
The Hab would use them only in an emergency; it has the oxygenator to balance the atmosphere.
The reason the O 2 tanks are here is to feed the space suits and rovers.
Anyway, the reserve oxygen would only be enough to make 100 liters of water (50 liters of O 2 makes 100 liters of molecules that only have one O each). That would mean no EVAs for me, and no emergency reserves. And it would make less than half the water I need. Out of the question.
But oxygen’s easier to find on Mars than you might think. The atmosphere is 95 percent CO 2 . And I happen to have a machine whose sole purpose is liberating oxygen from CO 2 . Yay, oxygenator!
One problem: The atmosphere is very thin—less than 1 percent of the pressure on Earth.
So it’s hard to collect. Getting air from outside to inside is nearly impossible.
The whole purpose of the Hab is to keep that sort of thing from happening.
The tiny amount of Martian atmosphere that enters when I use an airlock is laughable.
That’s where the MAV fuel plant comes in.
My crewmates took away the MAV weeks ago.
But the bottom half of it stayed behind.
NASA isn’t in the habit of putting unnecessary mass into orbit.
The landing gear, ingress ramp, and fuel plant are still here.
Remember how the MAV made its own fuel with help from the Martian atmosphere?
Step one of that is to collect CO 2 and store it in a high-pressure vessel.
Once I get the fuel plant hooked up to the Hab’s power, it’ll give me half a liter of liquid CO 2 per hour, indefinitely.
After ten sols it’ll have made 125 liters of CO 2 , which will make 125 liters of O 2 after I feed it through the oxygenator.
That’s enough to make 250 liters of water. So I have a plan for oxygen.
The hydrogen will be a little trickier.
I considered raiding the hydrogen fuel cells, but I need those batteries to maintain power at night.
If I don’t have that, it’ll get too cold.
I could bundle up, but the cold would kill my crops.
And each fuel cell has only a small amount of H 2 anyway.
It’s just not worth sacrificing so much usefulness for so little gain.
The one thing I have going for me is that energy is not a problem. I don’t want to give that up.
So I’ll have to go a different route.
I often talk about the MAV. But now I want to talk about the MDV.
During the most terrifying twenty-three minutes of my life, four of my crewmates and I tried not to shit ourselves while Martinez piloted the MDV down to the surface. It was kind of like being in a tumble-dryer.
First, we descended from Hermes , and decelerated our orbital velocity so we could start falling properly. Everything was smooth until we hit the atmosphere. If you think turbulence is rough in a jetliner going 720 kph, just imagine what it’s like at 28,000 kph.
Several staged sets of chutes deployed automatically to slow our descent, then Martinez manually piloted us to the ground, using the thrusters to slow descent and control our lateral motion.
He’d trained for this for years, and he did his job extraordinarily well.
He exceeded all plausible expectations of landings, putting us just nine meters from the target. The guy just plain owned that landing.
Thanks, Martinez! You may have saved my life!
Not because of the perfect landing, but because he left so much fuel behind. Hundreds of liters of unused hydrazine. Each molecule of hydrazine has four hydrogen atoms in it. So each liter of hydrazine has enough hydrogen for two liters of water.
I did a little EVA today to check. The MDV has 292 liters of juice left in the tanks. Enough to make almost 600 liters of water! Way more than I need!
There’s just one catch: Liberating hydrogen from hydrazine is…well…it’s how rockets work. It’s really, really hot. And dangerous. If I do it in an oxygen atmosphere, the hot and newly liberated hydrogen will explode. There’ll be a lot of H 2 O at the end, but I’ll be too dead to appreciate it.
At its root, hydrazine is pretty simple. The Germans used it as far back as World War II for rocket-assisted fighter fuel (and occasionally blew themselves up with it).
All you have to do is run it over a catalyst (which I can extract from the MDV engine) and it will turn into nitrogen and hydrogen.
I’ll spare you the chemistry, but the end result is that five molecules of hydrazine becomes five molecules of harmless N 2 and ten molecules of lovely H 2 .
During this process, it goes through an intermediate step of being ammonia.
Chemistry, being the sloppy bitch it is, ensures there’ll be some ammonia that doesn’t react with the hydrazine, so it’ll just stay ammonia.
You like the smell of ammonia? Well, it’ll be prevalent in my increasingly hellish existence.
The chemistry is on my side. The question now is how do I actually make this reaction happen slowly, and how do I collect the hydrogen? The answer is: I don’t know.
I suppose I’ll think of something. Or die.
Anyway, much more important: I simply can’t abide the replacement of Chrissy with Cindy. Three’s Company may never be the same after this fiasco. Time will tell.