His approach for the farms themselves was simple. Inside, there’s an active colony of Taumoeba and a Venus-like atmosphere. Also, there’s a coil of very thin steel-ish tubing full of Astrophage. The Taumoeba can only get at the outermost layer, so they have to work their way down the tube, which has a total length of about 20 meters. Some basic experimentation tells us that will last the small Taumoeba population several years. As for waste products—they’ll just stew in their own poop. The capsule will gain methane and lose carbon dioxide over time, but it doesn’t matter. Though it’s a small volume by human standards, it’s a vast, gigantic cavern to the tiny microbes inside.

The beetles have been a priority for me. I want them ready for launch at a moment’s notice. Just in case there’s a catastrophic problem with the Hail Mary. But I don’t want to send them off if there isn’t a mission-critical problem. The closer we are to Earth when they launch, the better their odds of making it there safely.

In addition to installing the mini-farms, I also have to refuel the little buggers. I’d used almost half their fuel supply when they served as ad-hoc engines for the Hail Mary. But they only need 60 kilograms of Astrophage each to be full. Barely a drop in the bucket compared to my supply of imported, Eridian-made Astrophage.

The hardest part is opening the beetle’s little fuel bay. Like everything else around here, it wasn’t intended for reuse. It’s like adding fresh butane to a Bic lighter. It’s just not meant for that. It’s completely sealed. I have to clamp it into the mill and use a 6-millimeter bit to get in… it’s a whole big thing. But I’m getting good at it.

I finished John and Paul yesterday. Today I’m working on Ringo and, time permitting, George. George will be the easiest. I don’t need to refuel him—I never used him as an engine. I just have to attach the mini-farm.

Figuring out where to put the mini-farm was another matter. Even with its small size, it’s too big to fit inside the little probe. So I epoxy it to the undercarriage. Then I spot-weld a small counterweight to the top of the beetle. The computer inside has very strong opinions about where the center of mass of the probe is. It’s easier to add a counterweight than completely reprogram a guidance system.

Which brings us to the matter of weight.