“Rich.”

Mike stood looking at Rich Purnell’s cubicle. Takeout boxes and scratch paper formed geological layers on either side of Rich’s monitor, with reference book inclusions and coffee mug geodes. The man himself had apparently achieved the perfect mind-meld with his computer monitor, clicking the mouse with his left hand even as he scribbled fresh notes with his right.

“Rich.” Mike put a hand on Rich’s shoulder. Rich in a working trance was much less physically dangerous than Rich sleeping.

Rich straightened up, blinked, and turned in his chair to face Mike. “What?”

“Your vacation is over, Rich. What the hell have you been doing?”

“Just a little side project,” Rich said, not meeting Mike’s eyes. “Something I wanted to-”

“I just got an order from Dr. Kapoor to bring you to his office right now,” Mike said. “Dr. Kapoor is pissed, Rich. He wants explanations. It looks like you’re about to be fired, and there’s nothing I can do about it anymore. Hell, I’m probably about to be fired, too!”

“But it’s not ready yet,” Rich said.

“Rich,” Mike said, taking a deep breath and trying not to think of the limited options his master’s degree in mathematics offered once he was blacklisted from government employment, “stand up and look around the room, please.”

Rich’s stubborn look changed to one of confusion, but he did as he was told. “Okay,” he said, after a quick sweep of the other cubicles with his eyes.

“That’s the rest of your team, Rich,” Mike replied. “Everybody at NASA is part of a team. And teams work together. Nobody tries to do everything themselves. If whatever this is was important enough to risk your job, then you need to tell us about it so we can all be working on it.”

“But it’s not ready,” Rich replied. “It might be a complete waste of time. I don’t want to waste anybody else’s time if it won’t work.”

“Rich, it’s too late for that,” Mike said. “If you or I don’t have something good to show Dr. Kapoor, and I mean really, really good, we are both out on our asses, do you understand me? It’s Judgment Day. What do you have that is good enough to save your job?”

Rich, to his credit, didn’t sulk or flounce back into his chair. He didn’t understand consideration of others or cooperation with others, but he did understand that he was supposed to, and he was generally ashamed when his failure to do so was called to his attention. Instead he clicked a few keys on the computer and stepped back to allow Mike to look more closely.

Mike looked. He scrolled down the screen. He grabbed papers at random, triggering a minor avalanche of trash at one point, and read them.

“Yeah,” he said in a choked voice. “This could be good enough.”

Venkat looked at the printout in his hands. It illustrated a complex trajectory stretching from Earth to Mars, then back to Earth, then back to Mars, then back to Earth a final time. “Sol 551?” he asked.

“Maybe,” Rich said. “Depends on the maximum velocity of the other vehicle, the reaction mass remaining for the VASIMR, the efficiency of the reverse Oberth effect… I’m still refining my estimates.”

Venkat tapped another part of the illustrated trajectory. “Isn’t this inside Venus’s orbit? That’s a flight-rules violation.”

“Hermes’s radiation mitigation systems can handle it,” Rich said. “Within the emergency margins, I mean.”

Venkat pointed back to Mars. “There’s no orbital insertion,” he said.

“Not enough reaction mass,” Rich said. “Also, need the speed to get back to Earth as soon as possible as a backup plan.”

“How will the MAV match speeds?”

Rich fumbled with the crumpled, coffee-stained papers he and Mike had brought with them, eventually pulling out three of them and handing them to Venkat. “Major modifications to the MAV,” he said. “Refueling the descent stage for extra lift. Adding thrusters from the alien ship to increase lift. The numbers are almost there. I just need a little more time.”

“How will Hermes have the supplies to get there?”

“We need another booster,” Rich said. “We could repurpose Sleipnir 3, but that’s not ideal, since so much of the payload is wasted with landing systems and other junk.”

“Okay.” Venkat set the printout down. The time had come to lead up to the big questions. “How did you bypass our approval system for sending emails through Pathfinder?”

“Approval system?” Rich looked blankly at Venkat.

Venkat returned the blank look. “You did know access to the aliens is restricted, right?” he asked. The question was both stupid and pressing. On the one hand, how could he not? On the other, how could he not?

“I didn’t know that,” Rich said simply. “I needed some answers and couldn’t ask Mike because I was on vacation.”

“In your cubicle,” Venkat said, shooting a glare at Mike. “Yes, we’re going to have a talk about that later. But you contacted them anyway. How?”

“I had the reply emails with the data I asked for about the alien ship’s performance,” Rich said. “I stripped out the headers and copied them into my system.”

Venkat blinked. “It can’t be that simple,” he said.

“It can’t be that simple!” Teddy snapped, his normally unruffled appearance breaking down for the first time Venkat could remember.

“Apparently it is,” Venkat said. “IT just added one extra flag in the headers for email requests to Pathfinder. If the flag is set to yes, the system automatically queues the message for transmission without human oversight. They did it that way to preserve privacy for pre-approved accounts. And all messages from Pathfinder automatically set the flag to yes. So when Purnell copied the headers, he got the approval flag without realizing it was even there.”

Teddy pulled himself together, his face returning to the reserved, proper expression he preferred. Only the pen in his hand, knocking against the desk, betrayed his continued agitation. “We’re going to have to re-evaluate that later,” he said. “It’s a tricky subject, but we can’t allow anyone else to do what Rich has done. For now, order all email headers stripped out of emails from Pathfinder except To, From, and Subject.”

“All right,” Venkat agreed.

“Now for the big question,” Teddy asked. “What was he asking about, and why?”

Venkat let out a long breath. “Purnell began with the idea of sending Hermes back to Mars without a refit,” he said. “Which is feasible, since we designed Hermes with a twenty-year operational life. The systems are robust. But the xenon tanks can’t be refilled without a refit. They’re removed and replaced in Earth orbit. There’s a massive safety margin in the tanks, but it’s not enough to break out of Mars orbit after the trip there. So Purnell’s main problem was getting Watney and his friends off of Mars on an escape trajectory that Hermes can rendezvous with.

“His main proposal addresses that, at least theoretically. Those numbers are still vague because Purnell is a trajectory man and theoretician- not an engineer. If we explore this option, we have to bring Bruce in, and maybe SpaceX too, to run the numbers properly. But it’d be tight all the way around, so Purnell wanted a better option- one that would get Mark, the ponies, Hermes, the whole lot of them, back to Earth in a few days.”

Teddy’s reserve broke again, his eyes widening in shocked realization. “The Sparkle Drive,” he said. “Purnell was trying to recreate the Sparkle Drive.”

“Almost,” Venkat said. “I don’t think Purnell ever thought we could build our own Sparkle Drive, or else orbital considerations and time wouldn’t apply. But one of the two designers of that drive is among the castaways, and we already know that crew was working on rebuilding their drive as part of an unworkable emergency-escape plan. And she sent us a pretty comprehensive writeup, complete with detailed equations in human mathematical terms for the underlying principles of the system.

“There are dozens of physicists, myself included, working on those equations, but we have other things on our minds- running Ares, teaching classes, raising families, and so on. But Purnell is pathologically single-minded. He doesn’t have distractions. What he did have was a rubber-stamped authorization to use the JSC supercomputers during low-traffic hours. That, and a good understanding of both Newtonian and quantum physics.

“Purnell was working on the problem of recharging the Sparkle Drive to avoid a repeat of the disaster that brought the aliens to our universe. He saw something in the description of the Drive that reminded him of string theory- he’s not the first to make that connection, by the way. Based on my own interactions with Starlight Glimmer, I’m guessing that the ponies haven’t explored quantum physics at all deeply, having focused instead on the physics of magic. Purnell’s proposed new equations, and the mathematical proofs he sent them, took them completely by surprise.”

“As much as magic took us by surprise?” Teddy asked.

“More so,” Venkat said. “To us magic is still a closed box, a mystery. We can’t relate. But Purnell’s modified equations struck the pony science community like a bomb because they could relate. He’d taken familiar structures and theorems and turned them inside out- and showed his work.

“And the tragic thing,” Venkat added, tapping the mass of papers on Teddy’s desk, “is that the whole thing is a dead end. Purnell thought the ponies already had all of this. He was hoping they would confirm a way of turning electrical current into magic power. But Starlight Glimmer already told me that magic power comes from a higher energy state than the other physical forces, so conversion is a practical impossibility. Purnell showed them a mathematical solution which, in theory, would make it expensive, but not impossibly so. If it checks out.”

“How is that a dead end?” Teddy asked.

“Imagine someone trying to convert matter into energy using Einstein’s equations,” Venkat asked. “In 1905. With no other knowledge than that the math says it should work.”

Teddy nodded. “Okay, I see,” he said. “Decades from now, maybe that would help, but you’re saying it won’t get Watney off Mars now.”

“That’s right.”

“Then what will?” Teddy asked. “Walk me through the proposed mission.”

Venkat pulled out the trajectory printout. “Hermes is due to begin braking thrusts in eleven days,” he said. “Instead of doing that, they accelerate. They fly by Earth to get a gravity assist, flinging them around the Sun inside the orbit of Venus. This puts them at Mars on approximately Sol 551. They take a specific trajectory which uses Mars’s gravity to slow them down relative to the Sun, which drops them back in-system for a new Earth intercept and a standard orbital insertion by aerobraking.

“Again, Hermes won’t orbit Mars. So the Ares IV MAV will have to be heavily modified. Somehow or other the alien ship will have to be hauled there- at least, all its engines and thrusters will, along with new batteries and a new Sparkle Drive. The main engines will be strapped to the outside of the MAV’s descent stage, which will be refueled using the residual hydrazine from the Ares III MDV and whatever other resources we can scrounge. We’ll strip any excess weight we can find from the MAV upper stages to make room for a small Sparkle Drive- Purnell was working within the five hundred kilo weight allowance for surface samples. The whole thing will launch as a three-stage rocket rather than the two stages it normally has.

“Purnell’s math works without the Sparkle Drive, but there’s practically no margin for error. Purnell didn’t like that, since he was using estimates rather than hard numbers. So he proposes three applications for the Sparkle Drive.” Venkat flipped over the trajectory sheet and used a pen to sketch Mars and a rocket leaving it. “First, the drive would be engaged as soon as the rocket lifted off, to get the ship out of atmosphere as fast as possible to reduce losses to air resistance. Then the ship would use Mars’s gravity to pick up speed while accelerating, to give the MAV enough linear momentum to match speeds with Hermes. The Sparkle Drive would then be used to bring the MAV close enough to Hermes for docking.

“And finally,” Venkat said, sketching Hermes next to the little rocket on the paper, “the Sparkle Drive would be adjusted for the addition of Hermes’s mass, and the whole assembly would be projected back to Earth. Given the power limitations of the Drive in our universe, Purnell estimates a month for the return journey if all goes well- eight days if the system recharges faster from the combined presence of the human and alien crews. And if the Drive fails, Hermes would still be on a return trajectory to Earth not later than eight months from the Mars flyby.

“Net result,” Venkat finished, “Mark and friends would be off Mars eight months earlier than scheduled and home at least six months ahead of schedule. Best case scenario, Mark would be home before Ares 3B is currently scheduled to depart.”

Teddy considered this. The pen continued to tap. “How feasible is this?” he asked.

“It has problems,” Venkat said. “Hermes doesn’t have supplies on board for the trip back to Mars, never mind the round trip or the additional mouths to feed. Purnell didn’t know enough about the MAV to make any practical suggestions for modifications. But they’re solvable problems.”

Teddy opened his mouth for another question, then shook his head. “We need a full staff meeting for this,” he said. “And we need to keep this quiet. We don’t want to get the public’s hopes up if we end up deciding not to do this.”

Venkat nodded. “I’ll pass the word discreetly,” he said. “When?”

“Tomorrow morning,” he said. “I want Bruce here in person for this, and it’ll take time to fly him in.”

“Got it,” Venkat said.

“In the meantime,” Teddy continued, “tell Purnell and his boss they’re not fired. His boss will have a reprimand entered into his employment record, and the matter will be closed.” He closed his eyes and added, “I’m picturing Purnell in my mind right now, Venk. I’m guessing a total media disaster if he gets on camera. Am I right?”

“I’m not Annie,” Venkat said. “But my judgment is, yes. Outside of government work or a university research center, he’d be totally unemployable. He’s just barely aware enough of his limitations to know people find him difficult, but he doesn’t know when or why.”

“Then keep a lid on him,” Teddy said. “The press probably have a photo of him by now. He’ll be mobbed the instant he leaves JSC. So do whatever you have to, short of physical force, to see to it he doesn’t leave. If we have to buy him new clothes and a steady diet of takeout, then that’s what we do.”

Venkat never understood why, when he asked Rich Purnell not to leave the space center grounds, Mike broke down laughing for three minutes straight.

Author's Notes:

Well, here it is.

No, Rich Purnell is not inventing human magic. Nor is he building a human Sparkle Drive. He's doing what he did in the book, what his expertise leads him towards.

The Rich Purnell Maneuver is now on the table for discussion. More on that in later chapters.

If I'd had more time or energy to think things through the past couple weeks, the previous few chapters would have been radically different or nonexistent. But the commitment to daily updates, no matter what, mean half-baked ideas sometimes have to be used. As Teddy Sanders might say, it is what it is, and how do we go forward from here?

I just finished writing this chapter. I have a lot of things to do today, and setup tomorrow in Lake Charles, but I'm going to try to write at least one more bit tonight sometime.

In the book it's never really explained why Hermes can't brake for Mars orbit and then return to Earth normally. There are two reasons. One, orbiting eliminates the free return trajectory to Earth. Two, although it's never explicitly stated. Hermes has limited reaction mass- that is, there's only so much xenon in the tanks for the VASIMR ion engines to hurl out the back of the ship.

And finally, to address complaints about "BFR has to refuel anyway to get to Mars!": in its current design as a Mars colonization ship with a massive payload, yes. Designs change, particularly when you're sending prepackaged, unmanned twenty-ton supply drones like an Ares presupply mission or one-ton landers like Sleipnir. Don't worry too much about whether or not a booster like Red Falcon will exist seventeen years from now or what its specific capabilities are. Andy Weir sure didn't.