To her left, the dome rose to almost half a kilometer: triangular glass panels separated by gleaming copper-colored struts that turned the entire structure into a massive Faraday cage. Bobbie had never been inside one of the greenhouse domes. She’d been sent out from Mars as part of a surge in troops to the outer planets and had been walking patrols on the surface almost since day one. Ganymede to her was a spaceport, a small Marine base, and the even smaller guard outpost she currently called home.
As they shuffled around the dome, Bobbie watched the unremarkable landscape. Ganymede didn’t change much without a catastrophic event. The surface was mostly silicate rock and water ice a few degrees warmer than space. The atmosphere was oxygen so thin it could pass as an industrial vacuum. Ganymede didn’t erode or weather. It changed when rocks fell on it from space, or when warm water from the liquid core forced itself onto the surface and created short-lived lakes. Neither thing happened all that often. At home on Mars, wind and dust changed the landscape hourly. Here, she was walking through the footsteps of the day before and the day before and the day before. And if she never came back, those footprints would outlive her. Privately, she thought it was sort of creepy.
A rhythmic squeaking started to cut through the normally smooth hiss and thump sounds her powered armor made. She usually kept the suit’s HUD minimized. It got so crowded with information that a marine knew everything except what was actually in front of her. Now she pulled it up, using blinks and eye movements to page over to the suit diagnostic screen. A yellow telltale warned her that the suit’s left knee actuator was low on hydraulic fluid. Must be a leak somewhere, but a slow one, because the suit couldn’t find it.
“Hey, guys, hold up a minute,” Bobbie said. “Hilly, you have any extra hydraulic fluid in your pack?”
“Yep,” said Hillman, already pulling it out.
“Give my left knee a squirt, would you?”
While Hillman crouched in front of her, working on her suit, Gourab and Travis began an argument that seemed to be about sports. Bobbie tuned it out.
“This suit is ancient,” Hillman said. “You really oughta upgrade. This sort of thing is just going to happen more and more often, you know.”
“Yeah, I should,” Bobbie said. But the truth was that was easier said than done. Bobbie was not the right shape to fit into one of the standard suits, and the Marines made her jump through a series of flaming hoops every time she requisitioned a new custom one. At a bit over two meters tall, she was only slightly above average height for a Martian male, but thanks in part to her Polynesian ancestry, she weighed in at over a hundred kilos at one g. None of it was fat, but her muscles seemed to get bigger every time she even walked through a weight room. As a marine, she trained all the time.
The suit she had now was the first one in twelve years of active duty that actually fit well. And even though it was beginning to show its age, it was just easier to try to keep it running than beg and plead for a new one.
Hillman was starting to put his tools away when Bobbie’s radio crackled to life.
“Outpost four to stickman. Come in, stickman.”
“Roger four,” Bobbie replied. “This is stickman one. Go ahead.”
“Stickman one, where are you guys? You’re half an hour late and some shit is going down over here.”
“Sorry, four, equipment trouble,” Bobbie said, wondering what sort of shit might be going down, but not enough to ask about it over an open frequency.
“Return to the outpost immediately. We have shots fired at the UN outpost. We’re going into lockdown.”
It took Bobbie a moment to parse that. She could see her men staring at her, their faces a mix of puzzlement and fear.
“Uh, the Earth guys are shooting at you?” she finally asked.
“Not yet, but they’re shooting. Get your asses back here.”
Hillman pushed to his feet. Bobbie flexed her knee once and got greens on her diagnostic. She gave Hilly a nod of thanks, then said, “Double-time it back to the outpost. Go.”
Bobbie and her squad were still half a kilometer from the outpost when the general alert went out. Her suit’s HUD came up on its own, switching to combat mode. The sensor package went to work looking for hostiles and linked up to one of the satellites for a top-down view. She felt the click as the gun built into the suit’s right arm switched to free-fire mode.
A thousand alarms would be sounding if an orbital bombardment had begun, but she couldn’t help looking up at the sky anyway. No flashes or missile trails. Nothing but Jupiter’s bulk.
Bobbie took off for the outpost in a long, loping run. Her squad followed without a word. A person trained in the use of a strength-augmenting suit running in low gravity could cover a lot of ground quickly. The outpost came into view around the curve of the dome in just a few seconds, and a few seconds after that, the cause of the alarm.