In the ten minutes it took to get home, even with the heater off, the interior of the rover became an uncomfortably hot 37°C. The RTG would definitely be able to keep me warm.

The trip also proved that my rigging worked. The solar cells and extra battery stayed beautifully in place while traversing eight kilometers of random terrain.

I declare Sirius 2 to be a successful mission!

I spent the rest of the day vandalizing the interior of the rover. The pressure compartment is made of carbon composite. Just inside that is insulation, which is covered by hard plastic. I used a sophisticated method to remove sections of plastic (hammer), then carefully removed the solid foam insulation (hammer again).

After tearing out some insulation, I suited up and took the RTG outside. Soon, the rover cooled down again, and I brought it back in. I watched as the temperature rose slowly. Nowhere near as fast as it had on my trip back from the burial site.

I cautiously removed more insulation (hammer) and checked again. After a few more cycles of this, I had enough insulation torn out that the RTG could barely keep up with it. In fact, it was a losing battle. Over time, heat will slowly leach out. That’s fine. I can turn on the heater for short bursts when necessary.

I brought the insulation pieces with me back into the Hab. Using advanced construction techniques (duct tape), I reassembled some of them into a square. I figure if things ever get really cold, I can tape that to a bare patch in the rover, and the RTG will be winning the “heat fight.”

Tomorrow, Sirius 3 (which is just Sirius 1 again, but without freezing).

LOG ENTRY: SOL 70

Today, I write to you from the rover. I’m halfway through Sirius 3 and things are going well.

I set out at first light and drove laps around the Hab, trying to stay on untouched ground. The first battery lasted just under two hours. After a quick EVA to switch the cables, I got back to driving. When all was said and done, I had driven 81 kilometers in 3 hours and 27 minutes.

That’s very good! Mind you, the land around the Hab is really flat, as is all of Acidalia Planitia. I have no idea what my efficiency would be on the nastier land en route to Ares 4.

The second battery still had a little juice left, but I can’t just run it down all the way before I stop; remember, I need life support while recharging. The CO₂ gets absorbed through a chemical process, but if the fan that pushes it isn’t working, I’ll choke. The oxygen pump is also kind of important.

After my drive, I set up the solar cells. It was hard work; last time I had Vogel’s help. They aren’t heavy, but they’re awkward. After setting up half of them, I figured out I could drag them rather than carry them, and that sped things up.