A middle-aged woman in glasses, her hair pulled into a tight bun, appeared on screen in front of a Prospector logo. Marshall guessed she was some kind of corporate communications type. “We have no information beyond what has already been provided,” she said firmly. “Our mission control teams are poring over the available data and will continue attempting to establish contact with Mr. and Mrs. Jiang.”
Poole froze the video on a depiction of Prospector’s position in orbit, adjacent to asteroid RQ39. “Here’s the skinny,” he said. “Last contact over eighteen hours ago, at 2314 Zulu. Here’s what they won’t tell you on the news: vehicle telemetry registered a temperature and pressure spike in their number one hydrogen tank before the whole platform dropped offline.”
The room erupted in groans. Poole patted the air with his hand in a gesture for quiet. “They lost all data for almost an hour before they could reacquire signal through one of the Ka-band antennas. The Jiang’s wrist biomonitors were still transmitting through the downlink, but those signals have gone weak to the point of being almost undetectable.”
“What’s their hab status, sir?” Flynn asked. “Is it pressurized, maybe cut off from the CSM?”
“Unknown, but possible. If a meteoroid holed the service module and they sealed themselves off in the hab, they’d still have limited comms,” Poole said. “It gets better.”
The crew exchanged glances, knowing “better” surely meant “worse.” “Here’s the fun part,” Poole said. “I don’t have to explain to you all what happens if a tank exploded: action, reaction, all that good stuff. Bottom line is it imparted enough radial velocity to bend their trajectory in the wrong direction.” He paused. “Without a course correction, Prospector will impact Mars in three months.”
He gave the crew a moment to digest that and turned to the XO to explain their mission. “We’ve been ordered to get underway immediately to intercept Prospector,” Wicklund explained. “First mission objective is successful rescue or recovery of the spacecraft’s occupants. Second objective is to change its course, either move it back onto a free-return trajectory to Earth or into a safe Mars-crossing orbit.” He looked at Nick Lesko, who Marshall had just noticed was in a corner wearing a generic crew jumpsuit. “First pass at our delta-v budget is on the order of fifteen kilometers a second, so we’re headed down to LEO to top off our tanks and shed any unnecessary mass. That means Mr. Lesko here will return to Earth, along with anything else we don’t absolutely need.”
There were no protests beyond wide-eyed surprise. Poole swiped at the controller and a plot of their orbits appeared. “Thank you, XO.” He took the time to meet the gaze of each crewmember. “We’re under serious time pressure, people. It took Prospector eight weeks to reach RQ39 with chemical engines and coasting on a free return. We’re going to do it in eight days.” He gave that a moment to sink in. “It’ll take a maximum endurance burn. Longest duration these engines demonstrated on Earth was an hour and forty, and that was because the test cell ran out of cryogenic hydrogen. I think they can do better, and I want every last second of that impulse. Got it?”
“Aye sir!” came their roaring reply.
“Good.” It was time to begin making assignments, and he looked at Marshall. “Mr. Hunter, you wanted to go somewhere? We’re going all right, into interplanetary space with our hair on fire. You’re going to work with Commander Wicklund and Chief Garver on our mass budget.”
“Aye, sir,” he said from behind his O2 mask. Mass budget, he thought. In this case, that no doubt meant deciding who got left behind.
14
Marshall rubbed at his eyes, chasing away mounting fatigue. How long had he been at this? Stupid question, he decided, and counterproductive as well: The only question that mattered was how long had the Jiangs been out of contact with Earth? Their lives now came with fixed expiration dates.
Of the many cold, hard truths about working in space they’d tried to teach him in school, the crush of time was the one he now felt firsthand. Of all the esoteric and sometimes confounding displays aboard a spacecraft, one of the simplest and most indispensable was the master mission clock.
It governed every aspect of shipboard life. Every maneuver, which simply put was burning the engines for a specific amount of time at a specific power setting along a specific vector, was defined by time: when, and for how long, measured to the fraction of a second. If they needed the ship in a specific point in space, its arrival had to be worked backward to the second where they could begin burning engines. There would always be some point on the clock where they had to take action or miss the opportunity entirely. If it were a simple matter of changing their orbit around Earth, then missing a window meant waiting ninety minutes for it to come around again.
Leaving Earth entirely was a bit more complicated.
Which made Marshall wonder why the skipper had put him on it. Were the more senior officers that overwhelmed? Because this was way too important to just be some make-work exercise for the new guy.
Ours is not to reason why, he told himself. Ours is but to do or die. And please do try to avoid that last part.
The XO had given him a hard deadline, essentially twelve hours from Poole’s briefing, when they were to rendezvous with the propellant depot in LEO. By the time they had tanked up and the evac shuttle had left with Lesko and the others, they were expected to get underway and Commander Wicklund wanted hard figures for Poole long before they arrived. The XO had made it clear that he and the master chief were going to be neck deep in logistics planning with the other division officers, and he was relying on Marshall’s recency of training to carry the day.
“You just had this stuff in the last six months,” he’d said. “For the rest of us, it might as well be theoretical. We’ve been too busy working up here to even think about doing a run like this, whereas you’ve devoted some time to the idea. So get to it, mister.” Nobody at the academy had warned him that cadet research papers could come back to bite so hard in the ass once they were out in the fleet.
The XO had been just as unsparing in his critique of Marshall’s first-pass calculations. “Too conservative,” he’d said. “The first critical event comes in ten days when their hab’s internal air supply runs out. We do not want to get there a day late. This ship can do a lot, but she has her limits. Find them, then find me a way to move them.”
Find the limits, like it was a first-semester calculus problem. Marshall ran a tense hand through his bushy black hair and wished he could’ve had an actual desk to sit behind. Working these problems with a tablet and notepad Velcroed to the wall of his sleeping berth was not conducive to concentration.
Prospector should have been on a free-return trajectory, taking advantage of RQ39’s current proximity to take some pictures and measurements, then continue on an ellipse that ended back on Earth.
The cold truth was a satellite could have done the same thing for a lot less money but the Jiangs had bigger dreams. They wanted to show it could be done, see it for themselves, and explore it. Exploit it, really, but the exploration had to come first. If it was as full of rare-earth minerals (and what could be more rare-earth than something not from Earth) as they believed, then it was worth the risk of matching its orbit to stop and look around it for a while.
The opportunity came roughly every four years, which in their minds made it all the more urgent—for what if they missed this opportunity, who else might come out four years hence to stake a claim? RQ39’s synodic period put it within relatively easy reach on a cycle that could conceivably be exploited by humans, so the Jiangs had been out to prove an operating concept as much as to explore a near-Earth asteroid.
That wasn’t making his current job any easier. Borman’s nuclear-thermal powerplants gave them options that Prospector’s chemical engines didn’t, but it didn’t change the fact that the optimal departure window had closed three weeks ago. They were going to have to expel a lot of energy to get there before that “first critical event,” in order to
reach a target that was flying farther away with each passing day. Then they’d have to burn again to slow down for a rendezvous, burn once more to accelerate back to Earth, then again to decelerate. There were some elegant tricks he could play that took advantage of Earth’s gravity to bend their trajectory, but in the end they’d have to slow this beast down enough for the planet to catch them—otherwise they’d be flung back out on a long ellipse that might as well have been as remote as RQ39’s.
It was just too much mass to move around. If time was the indispensable measurement, mass was the inescapable limitation.
What if it wasn’t? Poole had said they were going downhill to refuel and shed mass. So how much was he willing to shed? The XO hadn’t given him any insight. What about Garver?
Marshall opened up a message window on his tablet: HEY MASTER CHIEF. YOU UP?
He replied after a moment: IS THAT SUPPOSED TO BE A JOKE, SIR? COB IS THE ONLY BILLET ON THIS TUB THAT GETS LESS SLEEP THAN THE SKIPPER.
Point taken, he thought. JUST TRYING TO BE POLITE. I HAVE QUESTIONS. GOT A MINUTE?
Garver must have been thinking along the same lines: YOUR PLACE OR MINE?
The master chief’s sleeping compartment, which was still too small for Marshall to seriously consider calling “quarters,” felt lived-in to the point where he wondered if he would ever be that comfortable aboard. Every square inch of the wall opposite Garver’s sleeping bag was covered with photos arranged in a deliberate pattern. In the center were pictures of his family: his wife and sons, who appeared to be budding teenagers. Surrounding it were images from his time both above Earth and beneath the sea: submarines and spacecraft, dive suits and space suits.
Marshall tried not to be distracted by the panoply of colors; if he didn’t focus on them the hues and patterns came to resemble a quilt hanging above his bed. He realized that was precisely why Garver had arranged them so.
“So what’s troubling you, Ensign?”
Marshall found an empty area of sidewall for his tablet and notes, deciding to not waste his time with pleasantries. “I can’t make the numbers add up. We have the delta-v to get there in eight days, but not if we want to rendezvous and return.”
Garver rubbed his nose as he scrolled through the results. He paused at a graph of velocity change versus time: a series of irregular, concentric shapes bisected by diagonals, each representing a different period of days and total energy needed. “I see your point. Had a feeling that’s what you’d get hung up on. So you’re wondering about our mass budget.”
“I am.”
“As you should be,” Garver said. “As am I. As the skipper is, though he’s smart enough to not show that in front of the crew.”
“Would he want you telling me that?”
Garver smiled. “You’re assuming he told me that. I’m only guessing based on his actions and body language. HQ wrote a very large check and it’s up to him to figure out how to cash it.”
“Up to us, you mean.”
“Yes, that’s precisely what I mean.” He tapped at the graph’s eight-day line. “So this is our target, nonnegotiable. We have to figure out how to fit the mission inside of that energy budget.” He eyed Marshall. “You believe you’ve run out of ideas.”
“I don’t know how many I had to begin with, Master Chief.” Marshall sounded defeated.
“Good thing you came to me and not one of the other officers,” he said. “Because I, sir, do not care one whit about who gets credit for what. At least not among the officers. So what are your mass assumptions?”
“I started with standard loadout, but it became obvious that wasn’t going to work.”
“Could’ve told you that without even sharpening my pencil, sir. Only way we’re getting there with a full boat is on a Hohmann transfer, which would take too long, and we’ve missed the window anyway.”
“Right,” Marshall said. “So then I looked at limiting consumables to the expected trip duration. That has its own drawbacks.”
“You mean the part where if we have to stay longer, we run out of air or starve? It’s still viable, though. If we stay out there too long, at some point we’re not coming back within any kind of realistic timeframe. There’s your upper limit on consumables.”
“I thought about that. It still doesn’t move the ball far enough.”
“So you’ve trimmed all the fat. Now you’ve got to figure out which cuts of meat we can do without.”
“I was hoping that’s where you’d come in.”
“I have some thoughts.” Garver smiled, and pulled out his own notes. “We draw down to a skeleton crew. Not only does that save a hundred-ish kilos per body, it’s a big cut out of our ration budget.”
“You read my mind, Master Chief. But I’m not savvy enough to know how many crewmembers we actually need.” It would be about much more than raw numbers: who stayed on mattered.
“Don’t worry about that part, Mr. Hunter. I’ve already worked up a proposed roster.” He tapped Marshall’s graph, adjusting it for the new entry. “It still doesn’t get us far enough, though.”
Marshall scratched at his head, exasperated. “And this is where I hit the wall, Chief. I don’t see what else we can shed.”
Garver’s eyes glinted with the satisfied look of a tutor leading his student to a revelation. “What’s the mission, sir?”
“The mission? Intercept Prospector, rescue the Jiangs, and bring them back to Earth.”
“Any threats we should be worried about?”
“Another coronal mass ejection. Getting holed by a micrometeoroid. Major system failure . . .”
“All true, sir, and all wrong. I’m talking about hostiles. Do we expect to encounter any?”
Marshall’s eyes widened. That had been so far down his priority list as to put it out of his mind entirely, and Garver’s question was a stark reminder to not let that happen. “Well . . . no. All the potential threats are milsats in Earth orbit, not that we’ve ever had to engage any. There’s nothing out there but some stray boulders and a lot more nothing.”
“And is that something we need a full weapons loadout for?” Garver prodded further. “Vaporizing any rocks that might get in our way?”
The light went on in his head. “That’s a lot of mass we’re lugging around.”
“Indeed it is. Nearly all of it is for self-defense, and I’m not seeing what’s out there to defend against.”
Marshall thought about that. “We’d want some point-defense rounds for asteroid deflection in case we run across something uncharted. Say half a load. Maybe keep a couple of the ASAT interceptors in case we need to make something big disappear.” He paused. “Would Captain Poole be good with that?”
Garver stretched and stared at his wall of photos, eyes focusing on one in particular as if it held the key. It was an old one, of him and Poole from their Navy days with a group of others Marshall didn’t recognize, some of whom looked to be kitted out like SEALs. “It won’t be an easy sell, but if it accomplishes the mission, then yes.”
“A skeleton crew in an unarmed ship, taking it farther than it’s ever been,” Marshall deadpanned. “Where do I sign up?”
The reality was that in being the most junior officer, Marshall was likely to be the first in line to get cut, but not the only. He’d realized this, but now that they were presenting their findings to Poole he felt the press of the other officers’ eyes at his back for the first time. Not only was the new guy sticking his neck out, he was exposing others to the same fate.
“What does cutting this much of the crew do for our consumables?” Poole asked, though Marshall suspected he knew the answer.
“Over six and a half kilos per person, per day,” Marshall said.
Commander Wicklund approximated standing by Poole, his feet in a set of restraints and hands clasped behind his back. “Exact numbers, please.”
“Six point five-five-four,” Marshall said. “Apologies, sir. I thought it best to be conservative.”
As was hi
s way, the XO was unsparing in his critique. “This is not the time for padding figures, Mister Hunter. Tell us precisely what conditions we need to meet, and precisely what we can do to meet them. The captain will decide the rest.”
Poole went a little easier on him. “Normally I’d say you’re right to be conservative, but first let’s work it down to the gnat’s ass like the XO said. Then maybe we can start adding back mass.” He rubbed his ball cap across his bald head as he looked for holes in their plan. “So we’re eight days out, assume two days on station, maybe ten back?”
“We can save propellant on the return leg using a lower-energy trajectory,” Chief Garver noted, “but then we’re trading off consumables again.”
“More time in transit equals more food and water,” Poole agreed. “Especially if we have survivors to feed. We’re not going to assume they’ve reached room temperature yet.” He eyed them both. “Is that clear?”
Marshall spoke for them. “Aye, sir.”
Poole pulled his cap back on, smoothing out the brim. “And by that logic, we can’t plan on shaving propellant mass to take the scenic route home. If they’re alive then they’re probably going to need medical attention, so we plan to expedite.”
“Our plan assumed the same, sir. We hadn’t looked to save weight in medical stores.” Marshall pointed to another equipment roster.
“We may have to consider that,” Wicklund noted. “How many units of blood plasma do we need for two evacuees? How many liters of saline?” He was fixed on Marshall. “If you haven’t looked to cut mass out of medical, then you haven’t spent enough time with Flynn or Riley. Your plan is incomplete, Mister Hunter.”
Marshall forced himself to keep his eyes fixed on the plotting board. “Understood, sir.”
If Poole was concerned about that, he wasn’t showing it. He tapped at his chin as he thought. There were other aspects he found more troubling. “Talk to me about the weapons loadout.”
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