The trailer had tons more space now. It was time for experimentation.

The Hab has twelve 9-kilowatt-hour batteries. They’re bulky and awkward. Over two meters tall, a half meter wide, and three-quarters of a meter thick. Making them bigger makes them take less mass per kilowatt hour of storage. Yeah, it’s counterintuitive. But once NASA figured out they could increase volume to decrease mass, they were all over it. Mass is the expensive part about sending things to Mars.

I detached two of them. As long as I return them before the end of the day, things should be fine. The Hab mostly uses the batteries at night.

With both of the trailer’s airlock doors open I was able to get the first battery in. After playing real-life Tetris for a while I found a way to get the first battery out of the way enough to let the second battery in. Together, they eat up the whole front half of the trailer. If I hadn’t cleared the useless shit out earlier today, I’d never have gotten them both in.

The trailer’s battery is in the undercarriage, but the main power line runs through the pressure vessel, so I was able to wire the Hab batteries directly in (no small feat in the damn EVA suit).

A system check from the rover showed I had done the wiring correctly.

This may all seem minor, but it’s awesome. It means I can have twenty-nine solar cells and 36 kilowatt-hours of storage. I’ll be able to do my 100 kilometers per day after all.

Four days out of five, anyway.

According to my calendar, the Hermes resupply probe is being launched from China in two days (if there were no delays). If that screws up, the whole crew will be in deep shit. I’m more nervous about that than anything else.

I’ve been in mortal danger for months; I’m kind of used to it now. But I’m nervous again. Dying would suck, but my crewmates dying would be way worse. And I won’t find out how the launch went till I get to Schiaparelli.

Good luck, guys.

CHAPTER 19

“HEY, MELISSA…,” said Robert. “Am I getting through? Can you see me?”

“Loud and clear, babe,” said Commander Lewis. “The video link is solid.”

“They say I have five minutes,” Robert said.

“Better than nothing,” Lewis said. Floating in her quarters, she gently touched the bulkhead to stop drifting. “It’s nice to see you in real-time for a change.”

“Yeah.” Robert smiled. “I can hardly notice the delay. I gotta say, I wish you were coming home.”

Lewis sighed. “Me, too, babe.”

“Don’t get me wrong,” Robert quickly added. “I understand why you’re doing all this. Still, from a selfish point of view, I miss my wife. Hey, are you floating?”

“Huh?” Lewis said. “Oh, yeah. The ship isn’t spinning right now. No centripetal gravity.”

“Why not?”

“Because we’re docking with the Taiyang Shen in a few days. We can’t spin while we dock with things.”