Feldspar
Philip A. Kramer

Grand Prize Winner of the Jim Baen Memorial Short Story Award 2017

The soft Martian regolith shifted beneath the rover’s wheels. The automated systems detected the motion and ceased all forward progression. The rover compiled a diagnostic and sent the packet of data through its antennae to a satellite above the red planet, which relayed it to a distant blue dot.

Eight minutes later, within a studio apartment in San Francisco, a computer console beeped in warning. Blake caught sight of the flashing red light out of the corner of his eye, and his stomach sank. He sprang up from the futon and navigated through the piles of dirty laundry and pizza boxes to the opposite wall.

He sat down in his black ergonomic chair and considered the eighty-five inch screen in front of him. The status window in the lower left quadrant contained a new update.

<NAVIGATION INTERRUPTED_ 30 DEGREE TILT_ TOPPLING SEQUENCE INITIATED>

His eyes flicked to the rover’s camera feed in the upper half of the display. He let out a long breath upon seeing the desolate surface of Mars. The rover was still upright.

He rubbed at the stubble on his cheeks in thought as he skimmed through the attached diagnostic.

Feldspar, his rover, sat at the edge of a shallow depression. It wasn’t anything as natural as a crater, but a hole dug by one of a hundred identical rovers that roamed the surface of Mars. A kilometer distant, across the plane of Chryse Planitia, sat the squat shape of the MRS, the Martian Regolith Smelter, affectionately known as the Missus. The Missus didn’t allow any digging within a kilometer radius, so it was inevitable that the laziest of rover operators would travel just beyond the boundary to collect dirt. Here and there, larger holes were visible. Someone had even seen fit to print a flimsy-looking bridge across one such trench.

Project Regolith began four years ago when the MRS and its complement of one hundred rovers descended on a plume of exhaust to the Martian surface. At that moment, Mars became host to the largest sandbox game in human history.

TerraForm Games accomplished what the space industry could not by appealing to the most dedicated workforce on Earth: gamers. Gamers like Blake were willing to spend thousands of dollars on consoles and pay exorbitant monthly fees to perform tasks that others might have considered work. It may have been pocket change to some, but for Blake it had taken his entire savings to purchase the operating rights to one of the rovers.

He cracked his knuckles, and his fingers flickered across the armrest’s integrated touchpad. The sequence selector appeared on the monitor, and he scrolled through the list.

Due to the current position of Earth and Mars in their respective orbits, it took eight minutes for a transmission to reach Mars, and eight more minutes to return. The rover’s automated systems could detect, predict, and solve problems in real time, allowing the rover to operate on even the vaguest of commands from its operator.

Sixteen minutes and a slice of pizza later, Feldspar initiated the pre-programmed sequence. All six wheels spun at top speed, and with a plume of fine dust, the rover climbed free of the depression and was on the move again.

The MRS grew steadily in his field of view. It was a cylindrical structure constructed from pieces of the very booster that had brought them to the red planet.

Feldspar maneuvered up to one of the three vacant docks on either side of the structure.

Blake filtered some cloudy water from the tap in the kitchen and poured himself a glass as he watched Feldspar perform its transaction with the MRS.

When prompted, Feldspar soundlessly dumped a compartment full of rust-red dirt through a fine mesh screen and provided the coordinates of its collection. The MRS, equipped with an Alpha Particle X-ray Spectrometer, reported the content of iron oxide within the regolith a moment later.

The transaction was not over. The rover opened a second compartment, and a dust as black and fluid as ink poured out: pure, elemental carbon. It was a resource he quite literally pulled from thin air. Each rover’s AIR, Atmospheric Ionization and Recovery, module housed an ultraviolet laser within a chamber that pressurized the carbon dioxide-rich atmosphere. The laser reduced carbon dioxide into elemental carbon and oxygen gas. The carbon was an essential reducing agent in the smelting of iron, and the oxygen, if he chose to believe the propaganda, could eventually terraform the planet.

When the battery was fully charged, the MRS would heat the high-strength ceramic lining each of its chambers to 1300 degrees Celsius. After discarding the slag, the MRS would cast and form the metal into a spool of wire and exchange it for more regolith and carbon. The iron wire was the currency of Mars. With it, a rover could 3D print any structure its operator could conceive.

A few centimeters of wire jutted out of a port on the MRS. Feldspar’s manipulator arm, complete with pincers, latched onto it and guided the wire to a similar port in the rover’s side. After the wire was completely spooled within Feldspar, the rover backed away and waited for Blake’s command.

Blake directed Feldspar to the mountain of slag that had accumulated near the back of the smelter. The heap glittered in the sunlight. The slag consisted of many minerals, silicates and other components of Martian soil, which the MRS discarded after the smelting process. Most gamers considered it useless, but he always made a point to grab a few kilograms every time he visited the smelter.

The MRS didn’t allow any rover’s arms to descend lower than wheel level within the area in an effort to minimize digging in the kilometer radius, but the pile of slag stood much higher. The pincers at the end of Feldspar’s manipulator arm turned 90 degrees to expose a much flatter, shovel-like edge, and the small rover began to fill the regolith compartment with the flaky slag.

It took some time to fill the compartment, during which Blake scanned the various feeds he’d followed over the years. There was one missing from the list: NASA’s live feed of the Eos mission.

They’d probably found another vaguely bacteria-shaped formation and were preparing a press release, Blake thought as he rolled his eyes.

Six months ago, Blake had positioned his rover to watch the fireball entering the atmosphere as the Eos crew arrived. Watching the live feed had been surreal as humanity made its first footprint in the Martian dirt. The fascination soon wore off as they made their base and engaged in months of monotonous tests and maintenance. Part of his loss of interest was due to their repetition of things he had been experiencing for years. Yes, it was pretty during sunset, and yes, the regolith was annoyingly fine and clingy. He had been there long before they had.

Blake programmed Feldspar to return home once it completed its collection. At top speed, the rover could barely reach five and a half kilometers an hour. It was about fifty times faster than the first Martian rovers, but still barely walking speed. It would take just over five hours to cover the 28 kilometer distance. The route was anything but direct. The downside of a planet covered in soft regolith was the tracks the rover left by his passing. In order to keep his home hidden from other rovers with vandalism or theft in mind, he spent much of his free time backtracking and taking circuitous and misleading routes.

His secrecy and protectiveness left little room for friends on Mars, though he could say the same about Earth. He was pretty sure this made him the loneliest guy on two planets.

It was just after two in the morning in San Francisco, but it was only midday on Mars. His day was just getting started.

He shrank the rover feed to a small corner of his display and pulled up his design software. He was currently designing a parapet for a castle. Other rover operators were some of the biggest buyers of his designs, all eager to spend months printing structures that would serve no practical purpose on a lifeless planet. He was not so shortsighted.

Blake fully intended to live on Mars one day.

Hours later, the rover’s camera feed drew his eyes. Usually Feldspar was able to detect and navigate around any obstacle in its path, but it appeared as though the rover was headed straight for a series of rocks. When Blake maximized the feed, he saw that they weren’t rocks at all, but depressions in the soil. They were staggered, but spaced linearly.

It took a moment to realize what they were, and when he did, he froze.

Footprints.

He ordered the rover to stop, but the command didn’t register in the feed until sixteen minutes later, long after Feldspar had left the tracks behind. Blake, used to the delay, had already keyed in commands to backtrack for eight minutes and take a panorama.

During the transmission time, he’d begun to doubt what he’d seen. The Eos Base Camp was over 150 kilometers away in the mouth of Valles Marineris, a place of ancient glacial activity where astronauts had access to sub-surface water. Why would they come to the edge of their exploration zone? Chryse Planitia, where Project Regolith operated, was comparably barren and flat. There was also no logical reason to travel by foot. The vehicles they had at their disposal were many times Feldspar’s size and could easily outpace him.

Just as he convinced himself the footprints were instead a natural formation, the rover’s panorama arrived. Zooming in on the image, he saw the pristine impression of a boot. They were, without a doubt, footprints. It was impossible to say how long they’d been there.

Blake smiled and saved the panorama. It was not perfectly composed, but still breathtaking. He could probably sell it for a substantial sum.

He needed to move. The astronaut could return to his rover at any moment with samples, or whatever it was he had come all this way to collect.

Blake bit his lip in a moment’s consideration and then began to tap away at his touchpad. He programmed Feldspar to follow the tracks and take high-resolution panoramas every dozen meters. If a picture of some footprints was worth something, a picture of a member of the Mars expedition team doing field research would earn him a small fortune. With any luck, the astronaut would be just as surprised to see him and pose for a shot or two.

His hopes high, Blake sat glued to his chair and stared at the display. He hadn’t felt this much excitement in years.

As the tracks began to disappear beneath the rover, he wondered how far the astronaut had walked. He couldn’t see them or his vehicle in the panorama, despite the area being relatively flat.

Another detail drew his attention. The impression of the left foot was consistently shallower than the right, and was smeared in many cases, as if the astronaut had drawn his foot along the ground.

His grin faded and a chill prickled along his skin.

Was the astronaut injured?

This terrifying notion became all the more plausible when he recalled the NASA feed. Of course they would take the feed offline if one of the Eos crew was injured, he thought. The five other crewmembers were probably staging a rescue mission in a backup rover at that very moment.

He continued forward, unable to ignore such a crisis, yet petrified by the prospect of interfering with NASA in any way. Historically, TerraForm Games and NASA were on friendly terms. Much of the data the rovers collected had convinced NASA of the area’s suitability. But if one of Project Regolith’s rovers complicated an already life-threatening situation, Blake would incur the full wrath of everyone involved. The alternative was to let an astronaut go unaided in his time of need.

It soon became apparent that the astronaut was not as far away as he had feared. Feldspar climbed a very shallow incline and saw the tracks end at a large boulder in the distance. At second glance, it was no rock, but the astronaut sitting flat on the ground and facing away from him.

Blake’s stood from his chair and approached the display. Leaning close, he could see why he had mistaken the astronaut for a boulder. The red dirt clung to every surface of what had once been a pristine white spacesuit. The bulbous helmet was sagging forward, as if the astronaut had fallen asleep while sitting upright. A large pack, probably full of radio and life-support equipment, was lying on the ground next to them, a long crack running down its center. The sight did nothing to reassure him, and he bit his lip as Feldspar drew nearer.

When the rover detected the obstacle in its path, it slowed and began to circle. The wide-angle camera quickly brought the side and then front of the astronaut into view.

The astronaut was leaning forward and wrapping his calf with a roll of white tape. He had no way of hearing Feldspar’s approach. The astronaut’s helmet jerked up as the rover rolled to a stop, and he went rigid.

Blake could only guess at his expression. A gold, reflective surface covered the glass face of the helmet, blocking out all light.

The astronaut appeared to stare for a long moment and then looked around.

Feldspar’s camera turned in a slow circle, and momentarily, the astronaut disappeared from view.

A diagnostic, status update, and high-resolution panorama loaded on his screen within a few seconds of each other.

<NAVIGATION INTERRUPTED_ PATH LOST_ AWAITING OPERATOR INPUT>

The picture was something to behold: a member of the Eos crew, sitting alone and injured on the barren surface of Mars. It would appear on every news site in the world. It would make him rich.

His gut twisted into knots, and nauseated, Blake sat down and minimized the panorama. He opened his communication window, and a hiss of static issued from the speakers on either side of the display. Occasionally, the voices of distant rover operators would crackle into life and then fade. It was pointless; NASA would be using its own private channel.

Communication was going to be difficult.

His design software was still open in the background. He discarded his previous project and started another. His fingers danced across the touchpad. He typed in the text, converted it to a series of paths and vertices, and selected the plane of the sand nearest the rover. He disabled the print function and then sent the command.

The astronaut did not sit idle during the sixteen minutes it took for the signal to reach Mars and return. He finished wrapping his lower leg with tape and awkwardly came to his feet, testing his weight. He appeared to ignore the rover, perhaps disconcerted by its blank and prolonged stare.

The smaller, more fragile printing arm unfolded from the rover’s side and began to write in the sand. As soon as the arm began to move, the astronaut’s head swiveled to look. He took two hobbling steps forward to observe.

Frequency?

The astronaut considered the word for several moments then waved a hand as if to gesticulate some point. He was talking to someone on the radio, Blake realized.

Eventually, he knelt awkwardly to the ground a few yards in front of the camera, in an area of regolith that was undisturbed, and drew his finger through the dirt.

Here they were, two entities meeting on a distant world, drawing in the dirt in an effort to communicate. Had the circumstances not been so dire, he would have paused to appreciate it. Instead, he leaned forward and squinted at the display. He recognized the first number as the frequency, 403MHz. In much tighter spacing was a series of 32 numbers. It was a 32-bit encryption key, he realized. He guessed anything larger was pointless. Radio privacy was implied when on a barren rock currently 144 million kilometers from the rest of humanity.

He opened the channel and placed his finger over the transmit button. He paused. What would he say?

He tested his seldom-used voice in the quiet of his apartment and then pressed the button.

“This is the Project Regolith rover, designation Feldspar. Is there anything I can do to help?”

Shortly after opening the channel, voices began to emerge from the radio.

“Kate, be advised. NASA has informed me that giving a civilian access to a proprietary frequency is a federal crime.”

The astronaut shrugged, and then a woman’s voice sounded over the radio.

“Well, Ryan. Given the circumstances, I decided to take a risk. You can tell NASA to lock me up next time they see me.”

Blake’s eyes widened. The astronaut standing before him was Kate Winship, the Eos team’s geologist, and one of two women on the six-member crew.

“You really think it’ll help?” Ryan asked.

“These things are driving 3D printers, right?”

“It can’t exactly replace the rover you broke.”

Kate sighed.

“No, but I’d settle for a crutch.”

“That’s assuming he has the material. These things spend all day collecting dirt for a little over a kilogram of metal wire. I had a friend who used to play. It’s monotonous work.”

“It won’t hurt to ask. He’ll probably tune in soon, right? What’s the time delay? Eight minutes?”

His transmission, as premature as it was, was already speeding through space toward them. That didn’t mean he had to wait for her to ask politely.

His frayed nerves made his fingers shake as he pulled up Kate’s profile on the NASA website. She was a few years older than he and a good deal more attractive than the last woman he’d ever worked up the courage to speak to, with flashing blue eyes, high cheek bones, and short-cropped, blonde hair. Perhaps it was for the best that he couldn’t see her face, or else he’d become a blabbering idiot.

The website listed her as 175 centimeters tall. He did a quick estimation and guessed a crutch length of about 130 centimeters should do. He sketched out a cylinder about 1cm in width. He knew the tensile strength of iron well, and that width would be more than suitable to support the weight of her and her suit in Martian gravity. It would even leave him with some wire to spare. He also attached a flat base to the cylinder to prevent it from sinking too far into the dirt. On the opposite end, he added an oblong piece to support her under the arm. He then set a small rod into the main shaft to serve as a handgrip.

He reviewed the design twice and then sent it.

A moment later, his voice crackled over the radio.

Kate, who’d sat down again to return the tape to her pack and reconnect some hoses, looked up.

“Feldspar, is it? I’m glad we crossed paths.” She paused. “Ryan, he can hear me, right?”

“That’s affirmative.”

“Well, Feldspar. I find myself in a bit of a situation,” she said. She lifted her left foot a few centimeters off the ground and waggled it in emphasis. “I think I sprained something when I crashed. I’m not used to sharing the land with you rovers, so didn’t think to keep an eye out for potholes. It turns out my rover is capable of some unique things too, like somersaults.”

“I told her not to go so fast,” Ryan interjected.

Ignoring him, Kate continued. “And with the battery drained and solar cells busted, I have a lot of ground to cover before dark, which is approximately when I will freeze to death or suffocate.”

“NASA predicts the former.”

“As my crewmate has so courteously informed me, I will turn into a giant, Mylar-covered popsicle in about five hours. Right now, my only chance is to meet the rescue rover somewhere along the way, which is somewhat hard to do when I can barely stand. If you have any printing capabilities, I’d really appreciate a crutch or cane of some kind.”

“A little more information than he needs at the moment. Talk about pressure,” Ryan said.

Blake’s heart was racing. These past few years, he had grown accustomed to having nothing but time on his hands, time to wait, think, and plan, but now his action or inaction could decide someone’s fate. Ryan was right; the pressure was too much. His fingers shook so badly he didn’t think he could design anything. He was grateful he’d already sent the crutch schematics.

When he tested his voice, it shuddered. He took a moment to regain his composure.

“The crutch should be printing now. I designed it to meet your height and weight parameters. It’s pretty minimalist, so don’t expect anything pretty. If it doesn’t quite work, I can add or cut off some bits. I estimate it will take about thirty minutes.” He paused. “I’m sorry if rovers like me were responsible for your situation. Please, let me know if there is anything else I can do.”

Blake sent the message.

A dozen minutes later, the 3D printer arm began to move again. Its tungsten tip became white hot. The thin wire he had collected at midday unspooled and fed into the printer arm. It began to construct the crutch at its base, building the flat disk layer by layer. When it was large enough, the rover’s manipulator arm took hold of it for support.

Kate finished reattaching her backpack and limped over to look.

Again, his voice came through the speakers. He cringed at the sound of it.

“That was fast,” Ryan said.

“Thank you, Feldspar. I don’t blame you for any of this. I’ve always had a thing for speed.”

“And going further than you’re supposed to?”

“Come on, Ryan. I was almost to the mouth of Maja Vallas, kilometers away from Dromore crater. The potential for ice plugs is huge. The so-called ‘exploration zone’ is a joke.”

“Doesn’t feel like a joke now, does it?”

The speakers on either side of his display went quiet. When the crutch was finished, Kate pulled it free from the small rover’s grip. She tested her weight on it and walked in circles around Feldspar, making the occasional sound of approval.

Ryan broke the silence.

“Kate, be advised. NASA informs me that they’ve pulled the crutch design from Feldspar’s server. After extensive review and analysis, they concede that it will support your weight.”

Kate laughed. “Thanks NASA. Way to be late to the game. I’ve already tested it.”

“There’s something else. They say they’ve received permission from TerraForm Games to scrap Feldspar if needed. These rovers are equipped with some pretty impressive hardware. The battery and solar panels can get you a couple more hours of heat.”

“That’s pretty cold, NASA.”

“They’ve assured me they’ll purchase him a replacement rover. They can also convert the atmosphere into oxygen; there’s a port on its right side.”

Kate hobbled over and disappeared from view as she examined his small rover.

“Even if I could somehow form a perfect seal with that port, how will the rover power it after I’ve ripped the battery out of him?”

Silence held the line for a moment.

“They’re running the numbers.”

“I don’t really care what they say. I won’t strip down his rover. He’s been here for several years more than we have. The amount of scientific data pouring in from this game has been infinitely more valuable than anything we’ve collected so far.”

“Don’t give me that ‘for the sake of science’ crap.”

“Listen to yourself. This entire mission is for the sake of science.”

“You mean so much more than that,” Ryan said. The words spilled out of her crewmate in a rush. Blake could hear the desperation in the man’s voice.

“Ryan, I . . .” Her voice was softer now, sympathetic. “Can you move us to a private channel?”

Blake didn’t hesitate.

“Don’t worry about me. Do what you need to do.”

While the message was flying through space toward the red planet, Kate and Ryan continued their private conversation. With her golden visor in place, he could not see her expression, but her body language was clear. She was trying to tell Ryan to let her go, to give her up.

Blake slouched forward in his chair, thinking. He was not thrilled about someone scrapping Feldspar for parts; in fact, it was a recurring nightmare of his. But he would sacrifice anything to give Kate a chance.

Even as the thought echoed through his head, he realized there was something else he could sacrifice, something worth far more than a few hours of heat and air. It would give her more than just a chance.

A surge of hope straightened his back, and he scrambled at the touchpads. He tried to keep the smile from his voice.

“Also, if it’s any help, I have an insulated shelter about seven kilometers from here with two fully charged batteries and a tank of compressed oxygen.”

She went completely still when his message arrived and then shook her head slowly and gave a small shrug. A second later, Ryan’s voice came back on the channel.

“Hey kid, are you serious?”

“I think we have to assume he is,” Kate said. “What other choice is there?”

“You can scrap him.”

“Fine, I’ll scrap him if he’s lying,” Kate said in exasperation. “But if he’s telling the truth, I could have a place to stay while Svetlana and Dave come for me.”

Ryan sighed. “What are the coordinates?”

Blake read them aloud. He’d never given them to anyone before, and he couldn’t help but feel like all of his secrecy these past few years was for nothing. After today, everyone will have heard of Feldspar’s hidden home.

When the transmission arrived, Kate laughed. “That’s near Dromore crater.”

“I guess you’ll have a chance to see it after all.”

Rather than wait for NASA’s approval, Kate began to hobble in that direction on her new crutch.

Blake reinitiated his previous navigation protocol as Kate took the lead, creating tracks for him to follow. While the crutch helped her maintain a steady pace, he could tell by her winded conversation with Ryan that the seven kilometer distance pushed her to her limits. The deepening drifts of sand and the slight increase in elevation as they approached the crater’s rim tested her endurance even further. Rocks were strewn across the barren ground, their size and proximity causing Feldspar to pause and adjust navigation on several occasions.

During the last leg of the journey, Kate made a dismayed sound.

“CO2 scrubber is maxed out. My suit’s gonna start purging air to keep the CO2 levels below one percent. That’ll only last as long as I have oxygen and nitrogen to replace it, and I don’t have much.”

“We’ll see you through this, Kate,” Ryan said soberly, and then his voice became businesslike. “Feldspar, how much oxygen do you have, precisely? And what kind of fitting does the regulator have? NASA will send you more questions any minute now so check your inbox. They’ve also sent you the specs for the suit’s hose fittings. If it won’t fit your tank, you’ll need to print a suitable adaptor.”

Sure enough, the specs were already in his inbox with a fancy NASA header and the word “confidential” in large, red letters. Someone had made the adaptor with compatible design software, and the message asked him to add the female end for his tank. Blake promptly replied to the message, stating that he would just weld it onto the tank’s outlet to save time and ensure a better seal.

Dozens of other messages and inquiries about his shelter arrived immediately after his response. Blake did his best to address them all, but soon gave up and sent all of his detailed schematics. He felt a little violated at the thought of dozens of techs pouring over the designs he’d spent years perfecting.

Blake put NASA out of his mind long enough to respond to Ryan.

“I received it. I should have enough metal to make adaptors for both the oxygen and nitrogen tanks. Both are about forty liters large and average one thousand PSI.”

When Blake’s transmission went through, Ryan sputtered in disbelief.

“Nitrogen? I’ll buy that you somehow managed to print a tank and that you’ve pressurized it with oxygen, but nitrogen? What is the concentration in the atmosphere? Two percent? How could you possibly separate it from the other gasses?”

“Zeolite,” Blake said. “And a few other aluminosilicates. At high pressures, nitrogen sticks to the mixture. When the oxygen moves into the second tank, the pressure drops, and nitrogen is all that remains. I repeated the process hundreds of times. It should all be pressurized nitrogen. The regulator is something I’ve had to build myself, but I salvaged the compressor from another rover’s AIR module.”

“He’s right,” Kate said when his response arrived. “We have a similar system at Base Camp. Space stations and hospitals have been using zeolite for decades to concentrate oxygen and capture nitrogen. It’s called pressure swing absorption.”

“Where the hell’d he get zeolite?”

“I suspect he did his research before Project Regolith started. That’s why he named his rover Feldspar,” Kate said. Blake smiled. No one had ever puzzled out the origin of his rover’s name before. The last person he’d told had assumed it was named after some dwarven hero in a fantasy game.

“I’m confused.”

“Feldspar is a family of minerals called aluminosilicates,” she explained. “Project Regolith only had their sights on the iron in the dirt, so he found a use for the rest, the stuff they were just throwing away. They call it slag.”

Ryan made a sound that Blake could only describe as grudging agreement.

“I suppose you’re right. NASA just forwarded the schematics for the shelter. Get this; he’s filled all of the walls with slag. According to NASA, it’s as good an insulator as you’ll find on this planet. He even filled a pit with the stuff because it’s porous and effective at leaching water from the ground.”

“Are all Project Regolith rovers this resourceful?” She sounded breathless.

“Hardly. That friend I mentioned? He went by the name Lugnut and spent years printing a vintage car that has no chance of running.”

“It’s as if our rover operator intended to live here one day,” Kate said.

“You should really look at this thing, Kate. The schematics are like nothing I’ve ever come across.”

“I think I do see it . . .”

Beside Dromore crater was a wide but shallow canyon created by one of many ancient waterways that crisscrossed this region of Chryse Planitia, an area called Maha Vallas. A unique feature stood out among the others as they descended into the canyon. Imbedded in the wall of the ancient waterway was a flat, circular door. Years of exposure to the elements had tarnished its surface, but it still glimmered in the fading sunlight.

“Yeah, that’s definitely it.”

“I shut down the camera feed to conserve power. What are you seeing?” Ryan asked.

“It looks like an airlock. It’s set into the side of a rock face. Feldspar, did you dig through the rock somehow?”

Blake leaned closer to the microphone at the base of the display, but Ryan already had the answer.

“From his notes, NASA thinks it was an old lava tube that was exposed by erosion. It might even be an old water plug that slowly sublimated and formed a cavern. He’s reinforced the whole thing and sealed it off.”

“How do I get in?”

“Leave the entry to me,” Blake said.

They had moved to the very base of the door by the time the transmission went through. Kate dropped her crutch and sat down, leaning her back against the edge of the door.

Feldspar initiated the entry sequence. It rolled to a stop beside the large door and extended its manipulator arm. The pincers spread apart and inserted into a recess that was perfectly shaped to receive it. A small hole between the pincers led straight to the rover’s AIR module. The purpose of this feature was to air-dust the clingy sand from joints and solar panels. Instead, Feldspar sent the compressed oxygen into the door, where it fed into a piston near the hinges. The pressure drove the piston outward, easing the large door open.

Kate let out a low whistle and stood to peer through the widening gap. She limped around Feldspar and took a step inside.

“There’s a type of rubber surrounding the door. It’s a gasket, I think.”

“According to the schematics, they’re from the wheels of several salvaged rovers,” Ryan supplied.

“Will I lose coms if I enter?”

“Don’t think so. He’s had to operate in there too, remember. It looks like he’s placed an antenna from a rover out the top of the enclosure, on the edge of the chasm. There are salvaged solar panels up there too. That’s how he’s able to charge the batteries. Damn, this kid’s thought of everything.”

Feldspar’s automated sequence led him into the enclosure after Kate and then to another port. The rover repeated the previous sequence, but this time the pressurized air drove the piston in the opposite direction, closing the door.

Darkness engulfed them for an instant until Feldspar’s night navigation sequence activated, and a light on his camera module switched on. The space was only about as large as the room Blake sat in, except that all the corners were rounded and shone with a dull, metallic gleam.

There was a second, inner door to the airlock, which Feldspar usually left open, but they needed all the insulation they could get.

As Feldspar closed the second airlock door, Kate explored the small room. Her breathing was becoming strained, and her teeth were chattering. She succeeded in locating the narrow shelf holding the batteries. Several spliced wires, harvested from broken-down rovers, led from the batteries and up to disappear into the ceiling.

She removed her pack, dropped her crutch, and sat down beside the narrow shelf. She pried open the outer covering of the pack to expose tanks, wires, and hoses. Several minutes passed as she tried to pick up the battery leads and press them in to her own battery. The thick gloves and her undoubtedly numb fingers made progress slow.

“I can take control of Feldspar from here and operate him in real time. I can help you connect the battery leads. I’ve already patched into his camera, and the controls seem pretty straightforward.” The tension in Ryan’s voice suggested he was just as concerned as Blake.

“No, Ryan. The delay is annoying, I know, but he’s the only one who knows what he’s doing. Now, what’s the plan to get me more air? My nitrogen and oxygen are almost depleted.”

“Working on it,” Ryan said, even as Feldspar’s next sequence arrived, steering the rover around and toward the opposite end of the room.

Blake lined up one of the tank’s regulators in the display and pulled the hose adapter design from his software. He oriented it on the surface of the tank’s outlet and finalized it.

Kate sighed in relief.

“All right. My heaters are back online.”

The tungsten tip of Feldspar’s 3D printing arm grew white hot and cast a dim light on the wall. It eased closer to the tank’s outlet nozzle and began to deposit a thin layer of molten iron. It continued in a circular motion, leaving a line of glowing metal in its wake.

“Bad news. I’m out of gas. The CO2 will build up rapidly now that I can’t purge it.”

“So soon?” put in Ryan. “That can’t be right.”

“I was thinking the same. I suspect the crash damaged one of the tubes connecting my suit to the oxygen and nitrogen tanks. I must have lost a little every time the suit filled during a purge.”

“Feldspar, what’s the time estimate for those adaptors?”

“Twenty minutes tops for the oxygen tank adaptor. That is, it will take another twelve minutes once this message reaches you. It’s a higher precision print than the crutch because of all the fine detail.”

Every few minutes, Kate updated them on the CO2 percentage. It rose from 0.4 percent to 1.5 percent before his transmission went through. At each update, he felt as if the hand of a large, unseen clock was counting down to Kate’s death. The delay was not helping. What he was seeing and hearing was happening eight minutes ago, and he was powerless to step in and intervene.

“CO2 is three point one percent. Oxygen . . . ten percent,” she said. Her words were lethargic.

“All right Kate. I’m gonna need you to head over to Feldspar, he’s almost done with the adaptor,” Ryan said after a short pause.

Blake leaned back and sighed. If those words left Mars eight minutes ago, it was likely Kate had already connected her line and was breathing oxygen. He had done it. He had come across an astronaut in the middle of Chryse Planitia and helped her stay alive.

“Kate? Do you read?”

Blake sat up, but he couldn’t hear anything except for the faint sounds of breathing.

“Damn it. Stay awake, Kate,” Ryan said.

Silence greeted the command.

The video feed continued to show a view of the oxygen tank as Feldspar printed the last section of the adaptor. A moment later, a red light flashed beside his status display.

<SEQUENCE INTERUPTED_ CONTROL OVERIDE_ OPERATOR UPLINK SUSPENDED.>

Then Feldspar was moving on its own. Blake tapped his touchpad, but the system was unresponsive.

Ryan had taken control of Feldspar.

Blake stared in rising horror as Ryan steered Feldspar back to the shelf holding the batteries. Kate remained slumped against the metal wall next to it, unmoving.

“Damn you, Kate. Wake up. I’ve seen you handle ten percent oxygen before. You can do this.”

Feldspar’s manipulator arm jerked upward and then back down before Ryan gained control. The pincers reached out and prodded Kate’s motionless form. When she didn’t respond, the pincers opened and gripped her pant leg and tugged.

She didn’t move.

Mind racing, Blake pressed the transmit button.

“Ryan, I have an idea. Give me control,” he said. He programmed a sequence, his fingers darting across the touchpad. He had no time to triple check, no time to double check. He sent the sequence.

Ryan continued to tug at Kate’s suit, but the rover was barely half her size and she didn’t move an inch. He let go of the suit and gripped a hose from her open pack. He was trying to stretch the hose all the way to the oxygen tank. He was desperate.

A message appeared on his display. NASA was politely requesting that he not take any recordings or pictures and “respect her family’s privacy” by not going public.

Blake gritted his teeth. They had already given her up for dead.

He keyed in another command sequence, letting his patience and better judgement fade into obscurity as he acted on impulse.

A few moments after his message reached Ryan, the rover continued to try to wake Kate, going so far as to press its pincers into her injured leg.

“Kate! Wake up!” Ryan screamed over the coms.

The radio was silent but for Ryan’s panting and sniffling, and Kate’s labored breathing.

“Take it.”

And then Feldspar was his.

His prepared sequence delivered, Feldspar wheeled around and drove back to the oxygen tank. It extended its arm and reached toward the regulator. Gripping it with its pincers, it lowered the lever with painful slowness. Gas rushed out of the tank. He couldn’t hear it, but the pressure of it escaping created a small cloud of water vapor at the mouth of the tank. Feldspar’s arm swiveled to the right and gripped another lever, and Feldspar repeated the process with the nitrogen tank.

A moment later, Blake’s next sequence arrived and the rover’s AIR module opened. It evacuated all of the oxygen within its tank into the enclosure. Rather than close the port, he left it open, exposing the module’s sensors to the ambient air. Oxygen and nitrogen, which had been at a measly two percent a moment ago, were steadily climbing in time with the PSI.

After a handful of readings came in, he programmed Feldspar to cut off the gas when the oxygen and nitrogen reached normal levels and the PSI reached 14.7. He then compiled his riskiest sequence yet. His finger hovered in the air for a minute, and then it mashed the send button.

The pressure in his enclosed shelter continued to rise.

“It’s hopeless,” Ryan said, his voice soft. “Her oxygen is down to eight percent and her carbon dioxide is up to six. She doesn’t have any time.”

Blake cursed. Even Ryan had given up on her.

When the pressure reached one atmosphere, Feldspar lowered the levers on the tanks’ regulators and spun to face Kate’s prone body. Its six wheels eased across the small room and stopped before her.

“Feldspar?” Ryan asked.

Once more, the tip of the 3D printing arm glowed with heat. It extended outward, toward the golden faceplate.

“Feldspar!”

The golden face-shield reflected the glowing point with clarity until it made contact. Seconds later, the glass cracked and began to glow red and warp around the probe.

Blake no longer touched his controls. He pressed his palms to his stubbled cheeks and stared through the narrow gaps of his fingers.

The only sound was a sudden hiss from the coms.

Then the glow stopped and the arm retracted.

A perfect hole, no more than a centimeter wide, was melted into the face-shield.

He checked the AIR module’s readings: 21% O2, 78%N2, and 1% CO2. 14.7 PSI

Kate was still.

A lump formed in his throat, and he held his breath.

A gloved finger twitched, and then an entire arm began to move. It lifted to the helmet, and fingers prodded the hole melted into the faceplate.

Kate searched the neck for small clasps and then lifted the helmet to reveal a narrow, pale face with short-cropped hair.

She blinked her eyes, breathed, and then stared straight into the camera.

“Thank you, Feldspar,” she said, her breath fogging in the cold air.

Blake leapt to his feet, and his relief left him in a victorious roar. He wiped away tears he hadn’t known were there and then sat down again, nearly breaking his chair.

“It’s good to see your face,” was all he could think to say.

Ryan’s words were much more poignant and passionate, succeeding in bringing Kate to tears and inspiring laughter. But when Blake’s words reached her, she pressed her lips to her gloved fingers and reached out to press them against the rover’s lens.

They talked after that. Ryan didn’t interrupt but for the occasional status update. Blake told her where he was from, what he did for a living, and how this game had become his entire life. He even told her his real name.

She loved San Francisco and told him of a time she went there with her father, saw the Golden Gate Bridge, and Alcatraz, and had a pastry from a shop in the Marina District. Of all that, she remembered the pastry the most.

She had lived a life he could only dream of, yet it was he who had saved her life. He had come across her tracks, guided her to shelter, and pressurized an untested airlock. He had proven that this was not just a game, that they could litter the entire surface of Mars with livable habitats without risking a single human life. She made him feel capable of anything.

“I look forward to meeting you in person, Blake. Perhaps on a future Eos mission.”

Eos, Goddess of the Dawn, who had once lain with Ares, the Greek God of War, and was cursed by Aphrodite to remain in a state of love and longing for the rest of eternity. He could sympathize. His passion for the red planet hadn’t wavered since his first glimpse of it through a telescope on a field trip far away from the smog and lights of the city. Now he had a real chance of going there, a chance to escape a polluted world and build a new one.

The batteries drained of power as Kate’s suit labored to heat the air of the larger enclosure. With another hour left before the rescue team arrived, Blake offered her Feldspar’s battery. It took some persuading from both him and Ryan to convince her to take it.

Then, for the first time in four years, the screen went black and a new status flashed across his screen

<COMMUNICATION LOST_ BATTERY FAILURE_UNABLE TO REESTABLISH LINK>

Blake rubbed his weary eyes and stood. He walked over to the door and slipped his bare feet into a pair of shoes.

He opened the door to the bright sun shining down onto the west coast and stepped over the threshold. It was morning, and he was suddenly in the mood for a pastry.

Copyright © 2017 Philip A. Kramer

“Feldspar” is the grand prize winner of the Jim Baen Memorial Short Story Award competition sponsored by Baen Books and the National Space Society. Author Philip Kramer, Ph.D. is a biomedical researcher specializing in metabolism, oxidative stress, and aging research. He posts regularly on his website (pakramer.com), which promotes the use of accurate science in science fiction.