Terrestrial Astrogation

“Signal from Bumblebee. Bogey spotted, bearing .40-.13, estimated range 300 miles,” said Sam, Killjoy’s signalman.

Amelia, the pilot, quickly turned so that they’d have a good view in that general direction. While the ship was turning, Nate, the navigator, worked out exactly which direction to expect to see the bogey. Once the turn was complete, he pointed the telescope in that direction, and hunted around for it. It didn’t take long to find it, and he reported the bearing. Having bearings to the bogey from two ships rather than one gave them a more precise idea where it was; Bumblebee’s range estimate had only been a wild guess, though it had turned out not to be far off.

Sam relayed the bearing back to Bumblebee with the light gun. Contrary to popular belief, the light gun, rather than Killjoy’s real gun, was the second-most energy-intensive machine on the ship, behind only the engine. Space ships are fragile, so it doesn’t take much punch to kill them, and they have no reason for their guns to pack more punch than that. Being able to yell for help is just as essential for survival in space warfare as being able to shoot. Since as far as anyone can tell, sound doesn’t transmit through space at all, that means you need others to be able to see you yelling for help, from a vast distance away. Hence the extremely powerful light gun.

Bumblebee and Killjoy each took another set of bearings on the bogey, and passed them over to each other, which meant they now had enough information to determine the bogey’s velocity. Nate ran the numbers on his slide rule.

“It’s on an intercept course with Bumblebee,” he said, “They’ll make contact in about 12 minutes, and I don’t think Bumblebee has any chance of running away from them.”

Bumblebee was carrying some extremely valuable cargo from Habitat 6 back to Habitat 1. Habitat 6 had just been captured right after Bumblebee had departed it, so if Bumblebee and its cargo were lost, there was no going back for more. If anyone was on an intercept course for Bumblebee, there’s a good chance they knew all of this, and were targeting Bumblebee because of it.

Nate continued, “There’s no way anyone else can make it there to rescue them. We can probably do it, though. Turning, uh… .83-.25 or so, and accelerating at about an eighth of a g would be a good way to start.”

Amelia immediately followed those directions. Those directions were similar to her intuition, which was famously good regarding maneuvering in orbit (she had set a record for how far a trip she could take and return from alive, back in the early days of space travel when people first discovered how to get out of Habitat 1, before the math behind orbital mechanics was known), but it still generally works better to wait for input from the guy with the charts and a slide rule when possible.

The course change was Nate’s signal to calculate a more precise intercept course. “Do we want to engage them simultaneously with Bumblebee, or before?” he asked.

“Before,” said Amelia.

The rest of the crew simultaneously cursed under their breaths at that. Normally, you want to coordinate with your squadronmates to fight enemies simultaneously, rather than one at a time. The only way it could possibly make sense to try to fight a one-on-one dual with the bogey before Bumblebee was close enough to help was if Bumblebee getting out of the fight in one piece was more than four times as important as Killjoy doing the same, a value judgement that no one in Killjoy’s crew could endorse with much enthusiasm.

“Maybe push the acceleration to a sixth of a g, then,” said Nate, “and tell Bumblebee to run away.”

Bumblebee is already doing that,” said Sam.

Nate got to work plotting the intercept course, and when he was done, he gave Amelia a course correction and an even higher acceleration.

When they got close to the bogey, Joan, Killjoy’s gunner and engineer, fired a tracer at it, and, predictably, missed, but seeing the path of the tracer was helpful for lining up the next shot. The tracer rounds were a recent invention, having been invented during the current war, and caused an enormous improvement in gunnery accuracy outside of habitats. Their side had been on the verge of victory when the other side developed the tracers, and they would have lost if they hadn’t managed to reverse engineer the tracers and produce some themselves as soon as they did.

Nevertheless, Joan missed the next couple shots as well, though the last one was close. There was a loud cracking sound.

“We’re hit!” said Joan, unnecessarily. Usually, a ship falls apart instantly when it gets hit; the projectile must have just barely grazed them. Joan more usefully continued, “We’ve lost one oxygen tank and we’re losing fuel. I’ll patch up the fuel tank.”

“You’ll what?” Sam asked incredulously, as Joan grabbed a bag of leak repair equipment and jumped towards the door.

She unlocked the door (which was designed to seal against a habitat airlock, and was very much not designed to be opened in a vacuum), yanked it open, quickly propelled herself through it, grabbed the handle on the other side, and slammed it shut.

The air inside the ship was noticeably thin by the time she’d finished that step, but not dangerously so. The oxygen tanks were automatically releasing more air, with an audible hissing sound.

The exterior of the ship was not designed to be crawled across, and as such, did not have handholds. Joan had no way to get traction without being pressed against the ship. Luckily, Amelia caught on to what she was trying to do, and used maneuvering thrusters to push the whole ship towards Joan, so Joan could climb across it, and across from Joan so it would be like Joan was climbing downhill.

“What’s she doing? There’s no way she’ll make it back before losing consciousness!” said Sam.

“She knows,” said Nate.

“But then we’ll have no way to recover her before she dies!” said Sam.

“She knows,” Nate repeated.

Joan reached the fuel leak, and the rest of the crew watched her work through the window, while Amelia continued to push the ship towards her with maneuvering thrusters so she wouldn’t float away. Joan finished patching the leak just before passing out.

“That was lucky,” Nate commented, “I counted 16 seconds since she opened the door, though I might have been off slightly because I was distracted by Sam talking. That’s longer than people usually last, and it was a very efficient patch job.” Meanwhile Killjoy was tumbling a bit as a result of Amelia’s hasty maneuvering, and Amelia was busy straightening the ship out.

“Where can we get to now?” Amelia asked after stopping the tumbling, in a grim tone of voice that suggested she had a hunch about the answer.

Nate looked around with the telescope to get a good sense of their position and velocity.

“While I’m figuring that out, you’ll want to boost us .45-.40 by 50 feet per second,” said Nate. That would prevent them from getting too far away from where the habitats tended to orbit.

Nate checked the time by pointing his telescope at Earth’s terminator line, checked the fuel gauge, checked the charts for where all the known habitats should be, and started running the numbers for all the habitats it was even remotely plausible they could make it to, including enemy-controlled habitats where they could surrender. This took several minutes.

“Nowhere,” he finally announced.

“Okay, let’s look around for a new habitat. Sam, ask Bumblebee, if they’re still alive, and whoever else is in signal range, Queen of the Angels, maybe, to help us out,” said Amelia.

“Will do,” said Sam, “Bumblebee is alive, by the way. They just messaged that they destroyed the bogey.”

Nate and Amelia started looking around for undiscovered habitats, and Sam joined them once he was done sending the message. Searching for habitats was tricky, because from a distance, a habitat looks like a dim star when it’s in sunlight (and is nearly invisible when shadowed), so even when there’s a habitat in plain view, it doesn’t stand out from its surroundings very well. But they all knew their constellations decently well, so they’d know when they saw something out of place.

“Over there! I see something!” Sam said excitedly, pointing, after they’d been looking for several minutes.

“You’re pointing at Mercury,” said Nate, “Is there something else next to it?”

“No. Uh, I guess it’s just Mercury,” said Sam, dejected.

It was almost an hour later that Sam again saw something. “Please don’t tell me that’s Venus over there,” he said.

Nate took a look through Sam’s telescope. “Hm, no, that’s not anything I know about,” he said, “Looks promising. Send the bearing over to Bumblebee and Queen of the Angels; see if they can find it.”

From looking at how the unidentified object was moving, Nate became convinced it must be a habitat, even before Queen of the Angels replied with a bearing on an unidentified object that was a potential match for the one Killjoy had reported.

After a couple more bearing reports on the object from Queen of the Angels, Nate had a pretty precise picture of the presumed-habitat’s orbit. “We can definitely make it, but it will take a while. Bring us to .75-.25 at a twenty-fifth of a g.”

“Okay. Now, when you say ‘we can definitely make it’, do you mean we have enough fuel and oxygen to make it there, or just that we have enough fuel?” asked Amelia, while following Nate’s directions.

“Oh shit, uh, hold on. Let’s see if I can make this work,” said Nate.

After recalculating, he said, “Okay, we can’t get there before the oxygen tanks nominally run out, but the time the oxygen tanks are rated for is less than the amount of time before we lose consciousness, and I’m not sure exactly how much less, so I’ll just give you the fastest route we can do with the fuel we have and hope for the best.”

Amelia returned to the controls and brought Killjoy to the new course Nate had planned out, while Nate jotted down notes about what the rest of the course should look like. When they were done, the three of them joined hands and Amelia led them in a slow-breathing meditation exercise. After a few minutes of this, Amelia stopped, and said, “Sleep.”

Sam and Nate strapped themselves in and tried to sleep, and Amelia dimmed the lights for them. It wasn’t easy falling asleep when you didn’t know if you were going to wake up again, even when knowing that falling asleep sooner would make that more likely. But they both eventually managed; it helped that it had been a long day.

Amelia continued meditating, while being careful not to fall asleep so that she could keep the ship on course. It was unclear to her whether they were going to make it. The possibility occurred to her of throwing someone out the door to conserve oxygen, though she quickly rejected this idea. There were many drawbacks: She and Nate needed to stay, because they needed to take shifts piloting, since the journey would take too long for one of them to do it, and Sam didn’t know how to fly. Sam needed to stay, because he was the only one of them with any wilderness survival skills worth speaking of, so Amelia and Nate might not fare very well on their own even if they did make it to the habitat. Air escaping through the door as someone gets tossed through it would limit how effective an oxygen-conserving measure it would be. And, of course, she greatly preferred all three of them making it.

About a third of the way through the trip, Amelia woke Nate up for a shift, and went to sleep herself. About three-fourths of the way through, He woke her up again to take the last shift, and went to sleep again himself.

She made it most of the rest of the way. The oxygen tanks were long since empty, and she was very, very tired. She entered a confused, dreamlike state, and then jolted herself back into reality.

Had she fallen asleep? She didn’t know. Was Killjoy in the same place it had been when she’d last been paying attention? That one was supposed to be easy, but she didn’t know. A wave of panic washed over her as she realized how disoriented she was, and then she remembered where the habitat was supposed to be, she looked in that direction, and there it was. She could even make out its toroidal shape through the telescope. So close. How much longer?

It took her a while to think of a way to answer that question. She looked for Earth’s terminator line, and then looked at Nate’s notes on their course. Then she looked back at Earth’s terminator line again and wrote down the time so she wouldn’t immediately forget it again. She hadn’t missed any maneuvers, and there was just over 20 minutes to go. She wasn’t going to make it.

Maybe Nate could make it, if he had a higher tolerance for oxygen deprivation than she did, she thought. Of course, maybe not, and maybe even if Nate could stay awake long enough he wouldn’t be able to dock at the habitat, since they were cutting it down to the wire on fuel and he wasn’t an experienced pilot. But it was a risk she’d have to take, because she knew she wasn’t going to make it herself.

Amelia pushed herself over to where Nate was strapped in, grabbed him, and shook. He didn’t wake up. She punched him, and he stirred. She punched him harder. Nate awoke, they made eye contact, and then Amelia passed out.

Nate felt groggy as hell, and part of him wanted to just go back to sleep. But he understood what was happening. He slowly unstrapped himself, and made his way to the controls. It took him longer than it should have to get himself oriented, but soon enough he worked out where in space Killjoy was, and when.

They were a tiny bit off course. He worked out how to correct for this, reached for the controls, and hesitated. He was forgetting something; what was it? He looked behind him. Aha! Amelia was unconscious and not strapped in. She could get thrown across the ship and get injured if he adjusted the thrusters. He went over and strapped her in before returning to the controls, orienting himself again (he’d already forgotten which direction they were off course in), and correcting their course.

The habitat drew closer, to the point where Nate could see its toroidal shape with naked eye, and then to the point where he could see that it was large. He needed to make several more course corrections to make sure that Killjoy would come to a stop just in front of the habitat’s airlock. He was getting nauseous, despite usually being pretty impervious to spacesickness.

His terminal maneuvering was slightly sloppy, and by the end, the engine was sputtering and not producing as much thrust as it was supposed to, but he made it. He fired the docking harpoons and reeled them in, successfully sealing Killjoy’s door against the habitat’s airlock.

He went to the door, opened it, opened the airlock behind it, and took in a deep breath of fresh air.