36: Perfect Plans

First — Prev — Archive — Next

“What do you mean?” Plia asked.

“We got the idea from Arborea Celestia,” Ella explained. “Arborea is a ship with design problems. Just so, so many design problems. I mean, right from the fleet’s obsession with ring-shaped habitats… but more importantly, their whole ecological structure results in a truly ridiculous mass-per-person ratio that just makes the whole ship far more expensive to transport than any fleet ship needs to be. But that’s only true if you make the erroneous assumption that Arborea is a fleet ship, whose purpose is to be a home for an endemic population.”

“It is a fleet ship,” I said, confused. “And it is for people to live on.

“Only by legal technicality! And while people do live on it, their population is so low that that’s more of a side effect than anything. Much how the Vanguard’s true purpose is to transport goods between other ships, Arborea’s true purpose – though the Arboreans themselves deny this, which I ridiculous, I’ve seen their metrics and what they value – is as a giant laboratory. The fuel costs are simply the price of running a continuous ecological experiment of that magnitude for centuries while we travel between stars.

“Arborea looks ridiculous from the perspective of a fleet ship, but out purpose is the colonies, and for a colony, the math is very different. Mass is far less expensive – indeed, can be advantageous, depending on circumstances – in orbit around a sun. For a very young colony, what matters is labour and safety. You want to set things up so that the smallest amount of work is needed, because the less work each person has to do the more insulated you are from things like population collapses causing the colony to fail, and the safer and better you can do things, and you have the option to work harder and do more in emergencies. You also want the work to be as safe as possible, so your colonists aren’t all dying from mining iron or whatever, and you want the work to consume the least amount of resources like fuel and machine parts. There’s a time right after the fleet leaves and before the colony is big enough to bounce back from just about any disaster, and in that time you want to be minimising labour and minimising danger. Now, Arborea doesn’t really minimise labour; I’ve sen the numbers and maintaining their trees and preparing their food and so forth takes more time per calorie than just using biotanks. But that’s largely because of their reliance on traditional stock and simply refining their techniques and processes. If you’re willing to delve into some proper, serious genetic engineering, you can make plants do a lot more with very little work.” She smiled at her vine walls. “What you see here is living hull.”

“Hull? Like of a space ship?” Plia ran a hand along the vine wall.

“I wouldn’t travel anywhere in it, and I wouldn’t walk inside unprotected,” Ella said. “The Hexacorallia ships, which are the prototypes for our proposal for the new colony, are made with traditional metal and chrome, and I imagine that the colony ones will be too, at least for the first few generations. These vine pods would have to prove their ability to hold pressure for a good long while before it would be sensible to trust them completely; until then I imagine that people will walk through them in lightweight environment suits and with emergency oxygen, and use them for things like mining, not living.”

“I don’t think I’m understanding you,” Plia said. “You seem to be implying that these vines can live in the vacuum of space?”

“Indeed.”

“Long-term?”

“We assume so. We haven’t had anything exposed for more than two years, so I can’t absolutely verify them living longer than that, but they do seem to be thriving. Those experiments are on the cables near the middle of the ship, but we have some younger ones in vacuum chambers down the back, if you’ll follow me?”

We followed her to the back of the laboratory. There were three vacuum chambers the size of small rooms, with thick windows to look inside. Inside each, a chain held a large ice-covered rock in the middle of the chamber, and growing out of each rock was a pale, leafless ball of vines.

“The gravity affects their growth a little, which is annoying,” Ella said, “and why the long-term trials are in the middle of the ship and out in actual space. These are just for experimenting with new leaf shapes and so on, trying to make things more efficient.”

“The leaves are on the inside?” Plia asked.

“Oh, yes. Water loss was a big issue at first. Water needs to be able to evaporate from leaves for the vine’s circulatory system to work. And temperature control, of course; always a nightmare in a vacuum. Inside the ball of vines is an atmosphere of mostly carbon dioxide, and the vines can darken or lighten themselves to alter their sunlight capture to black body radiation ratio to maintain temperature. It’s all very efficient in heavy sunlight. Falls apart in heavy shadow, which is less than ideal, but energy has to come from somewhere.

“The goal, as you can probably see, is to plant these vines in the carbon and ice-heavy asteroids in the asteroid belt. The water, carbon dioxide and plant material can all be harvested from inside the ball, provided a mechanical port has been grafted on it, much more safely and efficiently than mechanically mining and processing it directly from the asteroids. It’s also a much, much slower process of course, but with preparation, that doesn’t matter at all. If it takes five years, you harvest from the asteroids sown five years ago while you sow new asteroids for in five years’ time.”

“How does it know which side to grow leaves and release gases on?” Plia asked.

“A mixture of pressure sensitivity and radiation. The vines block certain types of more dangerous solar radiation, and the light that gets through is absorbed by the leaves. So anything that is exposed to high levels of solar radiation is assumed by the plant to be ‘outside’. We douse one side of the experimental rows over there with radiation, and shine it in these chambers – don’t worry, those lights aren’t on right now. They’re disabled for safety whenever anyone’s in the room.

“Of course, this does mean that ideally the sown asteroids should rotate to assure as even solar radiation on the outside as possible, but not rotate in a way that blocks light from the vines so much that they freeze. Which is less than ideal. We’ve been experimenting with dropping that radiation dependency as much as possible and trying to get the vines to focus more on air pressure once they’ve established an internal atmosphere, but they get easily ‘confused’ by things like pressing up against the asteroid or against other vines and form wonky atmospheres, which can compromise hull integrity. And nothing that compromises the hull integrity is worth it, really.”

I didn’t understand most of this plant stuff, but that wasn’t important. What was important was Plia’s manner. She seemed politely interested, or at least she probably did to a stranger. But I could see that she was trying to move the conversation in a specific way. She had come here to ask something specific, and all of this was a way to make it sound natural.

“How high is the pressure inside?” she asked.

“One quarter of an atmosphere,” Ella said. “We’re aiming for one third by the time we reach orbit, but frankly there is no way to predict whether we’ll succeed or not. The leaves themselves can handle anything from vacuum to above an atmosphere – they’re doing just fine in the air of this lab, after all – but the strength of the vines is an issue. The materials they’re made from have a strength limit, and every time we do something to try to make them stronger it creates a lot of unpredictable problems in their growth patterns, growth speed, phloem movement, their ability to deal with pinhole leaks in the structure, the radiation blockage… the limits on how far we can go here, or the time it’ll take to get there, are completely unknown.”

“I heard,” Plia said, with a teeny tiny bit of excitement in her voice that told me that this was what she was after, “that you were having difficulty with the high levels of solar radiation and were looking into other ways to reduce it?”

“That’s true,” Ella said. “Open space is a really, really harsh environment, and we’re somewhat hamstrung by the fact that plants never evolved in an environment anything like it, so we’re working with limited stock.” (I made mental a note of the new word, ‘evolve’, so I could find out what it meant later.) “That’s not necessarily a problem for the plant itself; radiation resistance is something we can increase quite easily, and in fact genetic error correction would be of the highest priority anyway because the one thing we don’t want is some random spot mutation in a vine tendril changing its growth or sensory capabilities and putting a hole in the wall. But it would also be ideal if the environment inside the bubble wasn’t being constantly bombarded with deleterious levels of radiation. That’s sort of important for maximising the actual practical use cases of these things.”

“I heard you were reviving some old tech to do it.”

“‘Reviving’ is a strong word, it’s not like it’s lost technology, just mostly abandoned. But yes. Using an actual hull, even a transparent one, to block the radiation kind of defeats the whole purpose of these vines, but there’s an old, fairly mild radiation-blocking technology called an ‘electrostatic shield’.”

“That they used on the Courageous when it moved near lightspeed,” Plia said, not bothering to try to hide her excitement any more.

Ella didn’t seem to notice. “Exactly. Since it’s not really practical for anything in the fleet to travel at those speeds, and its actual radiation blocking capabilities are fairly weak and dangerous compared to just making a proper hull, it’s not something that has a lot of use these days. But we’re finding that electrostatic shielding in combination with the radiation blocking of the vines themselves works very well. The vines outside the ship are electrostatically shielded and it’s working very well.”

“Using the same systems that the Courageous used?” Plia was almost breathless now.

“Not the same systems, no. The field itself is the same, but we have much better equipment for efficiently generating one than our ancestors did.”

Plia tried to hide her sudden disappointment behind a look of polite interest. “Oh. Uh. H-how long did they take to develop?”

Ella shrugged. “I think Hexacorallia made the design that we’re using? They started building dozens of the things to shield a bunch of their little pods before we even confirmed that it worked, and as they made them they came up with improvements. They probably have some of the original design and a bunch of variations, and we used the most efficient one. That is something to say about Hexacorallia – call their system inefficient as a spaceship, but boy does it let them iterate on a design. Anyway, they’re going to start growing these vines on their pods within a few years because they want to show them in active use by the time we reach orbit, to prove the viability of our proposal for building the colony, so they’ve been putting electrostatic shields on everything just in case.”

“Including ones generated in the same way as the old Courageous one?”

“Uh, yeah, probably? I would assume?”

“Good to know!” Plia hung around a bit longer, politely listening to Ella’s explanations about her plants, before thanking her and leaving to catch up with the other historians. I had nothing better to do, so I stayed behind.

“What if you never get the air pressure inside higher than a quarter of an atmosphere?” I asked. “People can’t live in pressures that low.”

She shrugged. “Then the plants will be fairly useful instead of incredibly useful. A partial atmosphere is already pretty useful for lot of things, but the main advantage of these is their ability to grow in the asteroids and ‘mine’ their resources and convert them into organics. Besides, I don’t know the limits of genetic engineering. Maybe the colony will invent people that can live in one quarter atmosphere.”

The organics thing was a good point. Maybe it was the Rubbish & Recycling lover in me talking, but organic methods of breakdown and refinement were almost always the best, so far as energy use and emissions went. Usually the slowest, by a long margin, but it sounded like these plants would mostly grow on their own, not have to be babied like biotanks.

“Why’s Plia so interested in old tech?” Ella asked. “I’m just curious. I’ll drop it if it’s a secret.”

I shrugged. “I doubt it’s a secret, but I’m afraid I don’t know. They’re trying to dig up details on an old language to translate I diary that they think might be mistranslated. I have no idea what radiation shields have to do with anything.”

“Oh! No; that makes perfect sense.”

“… It does?”

“Yeah. The electrostatic shielding was invented prior to the launch of the Courageous, it was used on the original ship. So if they’ve got blueprints or whatever in the language they’re translating, maybe they want to get a look at ones built to those blueprints and confirm that the shields work with the right efficiency, thus confirming the accuracy of the translation?” She shrugged. “There’s no reason to come all the way out here to do that, though. They could’ve had an engineer on your ship build a small one for them. Or just messaged Hexacorallia and asked one of the scientists there to check.”

“I don’t think they came all the way out here to look at some old shields. They probably just heard about them and figured it was worth checking out since we were here. They spend most of their time looking through databases and stuff, for files.”

“That’s even easier to get sent over in a message!”

I didn’t bother explaining Plia’s speciality in tracking down misplaced, hidden or corrupted files, and how unless she was expecting entire ship’s databases to be sent back and forth, searching via messaging ships over and over would be a really slow way to do it. I just shrugged. “I think they’re looking for some pretty niche stuff. Our final destination’s the Dish.

Ella’s eyes lit up. “Ooh! Yeah, if you wanted to find Earth information, that’s where you’d look!”

“I would’ve thought you’d look on the Courageous,” I said, “but apparently we don’t have it, so the Dish is the next best thing.”

“Ugh, I’m so jealous. I wish I could go to the Dish. It’s a stupid wish, since I can just get them to tell me anything I need to know, but I feel like actually being in the information transfer hub of the fleet, actually touching the equipment with my hands, would be… I don’t know. I’d like to do it someday.”

“Is there any reason you can’t? Would they not let you aboard?”

“I’m sure they would, but I’m way too busy. I haven’t even had a chance to visit Hexacorallia in person. We need these plants to be in as good a shape as we can get them by the time we reach orbit, for our colony bid. Maybe I’ll have more free time when we hit orbit.”

“My Auntie Lia always says that work is a gas that expands to fill the amount of time it’s contained in. That there’ll never be free time if you simply trust the work not to fill it on its own.”

“Ha, maybe that’s true.”

“A bit off topic,” I said, “but I actually have a question that isn’t about space plants.”

Ella glanced around, leaned very close, and spoke quietly. “Let me guess. You want to know about the capuchins?”

First — Prev — Archive — Next