6
Phobos
There it was. The Japanese telerover’s software had notified Will of a whitish-gray stone and his control computer had analyzed the infrared signature automatically; there was evidence of carbonates in it. They had not found much carbonate on Mars. Will requested the location and the stone was immediately highlighted on the screen by a flashing white circle. Will moved the joystick and the rover responded, rolling to the rock. It was small; perhaps six centimeters long.
After staring at it for a few minutes, Will grabbed the joystick controlling the manipulator arm with the rock examination system and moved it down to the rock. He turned to another screen, where a short-focus, high-magnification microscopic camera zoomed in on the surface; the crystals looked a bit like calcite. Simultaneously an alpha-backscattering device extended to contact a side of the rock; in five minutes his control computer would have an analysis. While it collected its data, Will turned to infrared and ultraviolet reflection and absorption spectra, for above the sample there were sensors for both. That preliminary data came back in thirty seconds; definite evidence of calcium carbonate. They had another piece; it was obvious even before the alpha backscattering had given its verdict. Will would definitely be transferring part of the sample to the storage bin. If all went well, in a year or so they’d send a solar-powered aircraft down to the northern edge of Alba Patera where the rover was operating. A ten-meter whip with a large hook on the end would be deployed into the air and the aircraft would hook it, pulling the sample bin free. It would fly it back to Aurorae over a week’s time, so they could haul the pieces back to Earth, and drop a replacement bin, which the rover would pick up and place it where it could receive more samples.
Will’s attaché beeped, warning him of an incoming videomail. Having spoken to his mother and sister that morning, he was not expecting a call from them. That meant it was probably business; and sure enough, it was. Jerome “Jerry” McCord was finally returning his call of the evening before. He activated the message.
Jerry’s face flashed onto the screen. He was older than Will—46, rather than 34—and balding, but otherwise they were both of medium height. He looked tired. “Will, sorry I didn’t reply last night. We’ve been burning the midnight oil here lately. Look, this Russian scheme for going to Phobos has everyone here furious. They’ve been angling for it for years. I wish we have never included them; we didn’t need their engineers, we don’t need their Phobos fueling plant, and the good Lord knows we didn’t need their financial contribution. We only have so many number one accomplishments; we gotta spread them out. You certainly shouldn’t feel guilty for breaking the driller; it wasn’t your fault. You had permission to try everything you tried. The driller can be fixed at the end of your mission; you’ll have to linger in Mars orbit at least a week anyway. Or it can be fixed by Columbus 2. Please help us by getting this scheme put behind all of you. You’ve got plenty to do in orbit, anyway. Bye.”
Will watched the screen fade and felt his anger with his friend mount. He moved in front of the screen so that the camera would capture his face better and hit reply. “Thanks for the reply, Jerry. Look, if I can put this matter delicately, I think you guys need to reconsider a few assumptions. First, this isn’t a Russian scheme; it was my idea. And it wasn’t my idea out of guilt; like you said, I did everything I was expected to do. The cable shouldn’t have broken under the stress we put it, and the guys in Moscow are still not sure why it did. So why should we do this? We really don’t have plenty to do here; there are only two functioning rovers left on the surface and we can drive them only about eight hours a day. So that’s part of our day. Laura, David, and Shinji can keep them going, I could help from Phobos, or we could drive them less now and more later. They’re supposed to keep going two more years, after all. An extra six hours of driving per day for two weeks is only an extra ten minutes a day for a year and a half.
“But the important reason for doing this is because it makes the Mars transportation system fully functional. Why shouldn’t we do that? It means that even if the second Phobos lander and its drillers don’t work, Phobos can still make 90 tonnes of methane and oxygen fuel by the time we fly back to Earth, which is plenty to get us back to Earth with just about all the Mars rocks we want—up to forty tonnes!—or with plenty of fuel for the next flight to Mars from the Lagrange 1 Gateway.
“As for the number of firsts, so what? Do you really think it’ll take away from the excitement of landing on Mars? Hardly. Columbus 2 can always visit Deimos, if you want. That’s a new ‘first.’
“I think you guys’ problem, basically, is rivalry with the Russians. And I think you should get over it. Our purpose here should be to focus on exploring Mars and its moons, not on national rivalry. The Russians have created an excellent fuel-making plant and they’ve landed some great scientific instruments for exploring Phobos. The flight analysis engineers say the risk of failure is 0.002 or one in five hundred. That’s safer than the old Space Shuttle! So Jeremy, give it to me straight: What’s the problem? Because I simply don’t understand. We can easily get there, repair the two drills, explore for a few days or a week, haul rock samples to Mars and then back to Earth, then head to the surface. No risk. A valuable scientific bonus. A valuable engineering bonus as well.
“Look, you and I have explored the Aitken Basin and hiked to the top of the Mount of Perpetual Sunlight. There were risks in that trip; we pushed our oxygen supply just about to the limit, we scaled slopes outside our allowable range, etc. Above all, we rewrote the rules. But we did it; we succeeded. This is a much simpler plan. Jerry, what’s NASA scared of? Bye.”
Will had surprised himself by his remarks; briefly he debated whether to send them. Then he hit send on the computer screen and turned back to the rover.
Laura popped in a few minutes later. “Sergei just unstuck the one solar panel on Phobos that hadn’t deployed properly, so don’t use that as an argument any more.”
“He did?”
She nodded. “Live control of a rover can do wonders. Of course, the driller had 90% of its power beforehand, so it wasn’t badly needed. How’s Alba?”
“I just found a chunk of carbonate, so I grabbed it. The alpha scan should be done by now.” He pushed a few buttons. “Yup, it is, and it’s komatiite instead! That was always a possibility.”
“Well, we don’t have many samples of komatiite either. Good to know it’s found here, too.”
“Yes, many theories of the magmatic evolution of the Martian interior predict komatiite, especially earlier in the Noachian. But I want to find limestone!”
“We’ll find it eventually. See you.” Laura popped back out as fast as she arrived. Ten minutes later Jerry McCord’s response arrived.
“Will, you have some interesting points,” he conceded. “I think you’re right about rivalry; but then, we’re Americans and they’re Russians! That won’t go away. But you’re right about Aitken. You have to stretch the rules sometimes to accomplish things. Of course, I’m not sure the time to stretch the rules is the very beginning of the mission! Usually you earn the right to stretch the rules. We’re meeting about this in six hours. I’ll convey your points then.”
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Much to the Columbus crew’s surprise, the result of the meeting—reported to have been noisy and chaotic in Houston, Paris, Moscow, and Tokyo simultaneously—was a green light. The media had a field day reporting about it, but the crew began to prepare immediately. The Columbus complex had to be despun, the Mars shuttles undocked, their aeroshields brought over to the aeroshields of the interplanetary habitats and attached to them for storage; the 7.5-tonne aeroshields were needed for arrival at Mars and Earth but were not needed for incremental aerobraking and landing on Mars. The Lifter Stickney on Phobos had to take off and fly into a Phobos transfer orbit, which it did. The Elysium had to be set up for the expedition. And there was the matter of finalizing the crew; the Olympus was scheduled to fly to the Martian surface with Laura, David, and Shinji, which implied that the Elysium would fly to Phobos with Sergei, Will, and Ethel. But David wanted to switch with Ethel and go to Phobos as well. After discussion, that was vetoed; the geologists would have to fly down on two shuttles, to make sure at least one of them arrived.
They had three days before the next launch window opened. Ironically, as they completed preparations, the dust storm at Aurorae abruptly and unexpectedly began to clear; but they weren’t going to change their plans now. On 19 February 2021, the Elysium departed from Columbus Station and fired its engines briefly, dipping its periapsis into Mars’s thin atmosphere. A brief, firey ride slowed them by 600 meters per second and lowered the apoapsis to a point just 100 kilometers above the orbit of Phobos. A second small burn raised the periapsis to 400 kilometers; well above the Martian atmosphere. They were now in basically the same orbit as the Stickney. Sergei and Ethel were both trained pilots and alternated in the control seat. In 26 hours they caught up with the Lifter.
The shuttle had come equipped with a docking funnel, which they had installed via a space walk before leaving Columbus. When the two vehicles docked nose to nose, the four fuel transfer pipes aligned, docked, and clamped together as well. A short firing of the attitude control system set the docked vehicles to rotating slowly, making a sixth of a gravity in the crew module; sufficient to use the shower, and sufficient to settle the fuel so that it could be pumped from vehicle to vehicle. The Mars Shuttle had a mass of fourteen tonnes, plus ten tonnes of liquid hydrogen feedstock, ten tonnes of supplies, and eleven tonnes of methane and oxygen fuel; they pumped on board 14 tonnes of methane and oxygen, enough to land on Phobos and head for the surface.
They took their time and pumped the fuel slowly, over six hours. Then they undocked and waited another three and a half hours until they could fire their engines at just the right moment. Phobos had come along in its orbit and would otherwise have flown by several hundred kilometers away. After the engine burn the Elysium was in a circular orbit a hundred kilometers above Phobos and the moon slowly gained on them.
“I can see the volatile processing plant,” said Will, looking out one of the forward navigational windows. “It’s on the upper limb.”
Ethel looked out; Sergei was piloting. “I see it. Pretty easy to spot, isn’t it.”
“Six hundred fifty square meters of solar panels makes it stand out like a sore thumb.”
“Why didn’t they land it at one of the poles?”
“Phobos and Deimos don’t get perpetual sunlight at the poles; they orbit the Martian equator and thus share the planet’s polar inclination.”
“Half a year of sunlight and half a year of darkness.” Ethel nodded. “And why isn’t the VPU on the side of Phobos facing Mars?”
“Because Mars eclipses the sun about 20% of the time on that side, but on the side facing away from Mars the sun can’t be eclipsed when it’s up, by definition.”
“True.”
“We could go see Mars if we wanted to, though. The VPU isn’t far from the edge of the hemisphere facing Mars.”
“The Russians’ proposed excursions look fascinating,” agreed Ethel. “I hope we can get to Stickney.”
“I want to see one of the fissures the Stickney impact made. But walking around the moon will be very difficult, as has been pointed out to us repeatedly. So the big question is whether the backpacks have enough maneuvering gas. We can’t pull out the buggy, after all; it’ll bounce into space.”
“It sounds like ski poles will work pretty well to anchor us to the surface, too,” added Ethel. “I guess we’ll see. We can’t do much geology if we’re floating twenty meters above the surface.” She smiled at him, and he smiled back. There was no question that they liked each other, even though they had not spoken about it.
They watched the moon approach. The cameras took a constant stream of high-resolution video images and sent them back to Earth via the Mars communications and navigation satellites. When they were about fifteen kilometers from Phobos, Mars began to disappear behind it; quite a pretty picture. Finally, when they were just a kilometer above their landing spot, Mars disappeared completely.
In one respect, landing was tricky: Phobos had only seven ten-thousandths as much gravity as Earth, so the Mars shuttle with its mass of about sixty tons had a weight of only 42 kilograms, about half the weight of an adult man on Earth. Sergei brought them in slowly and slowed them down as they approached. The landing process took six hours; Ethel, then Will caught lengthy naps as they approached. The last hundred meters alone took half an hour. Finally, they watched the five landing legs sink into the fluffy regolith covering Phobos, and sink, and sink, and sink; they went in over a meter before stopping. There was no sound or feeling of coming to rest, and no change of gravity.
“We’ve landed on Phobos,” announced Sergei. “It was so imperceptible, only the instruments have detected the event. Nothing seems to have changed here in the cabin.”
“Congratulations, Elysium,” exclaimed Laura. “We’ve been watching and waiting, and we’re delighted.”
“Thanks, Columbus 1,” replied Sergei.
“It’s time to suit up,” said Ethel, unbuckling her seatbelt and floating free in the small cabin.
“Hey, let me finish shutting down some systems! I’m supposed to be the first one out.”
“Sergei, I can shut things down; I’m scheduled to be last out, after all,” said Will. Sergei nodded, so they switched seats.
Will kept an eye out on Sergei and Ethel as they stripped down to their underclothes and wiggled into their suits. He followed soon after. It was a complicated process to suit up in a small cabin and in weightlessness. The crew module was six meters in diameter, but it was divided into four pie slices, each an average of three meters wide and six meters along the outside wall. One slice held the bathroom, kitchenette, and life support equipment; another was the main room, where they ate, exercised, and controlled the shuttle, where one of the ITV’s plant growing cabinets was anchored, and where a tonne of spare parts was stored; another slice had two sets of bunkbeds facing a narrow common space partitioned with curtains; the fourth slice was packed with three tonnes of food and water, a half-tonne solar power unit, a drill, a lightweight one-person four-wheeled vehicle referred to as a “buggy,” geological and laboratory equipment, and a second plant growing cabinet that also had their chickens and rabbits.
Will helped Sergei and Ethel suit up, then they helped him. Sergei and Ethel squeezed into the tiny airlock; it could hold only two at a time; then once they were out, Will climbed in as well. As the lock depressurized, Will could hear Sergei exclaim “The human presence begins on Phobos”; his first words on the moonlet. Then he could hear them struggling on the surface; walking and zero gravity were not compatible.
Will floated into the airlock and depressurized it, then pulled the outer door open. Phobos stretched out before him: gray and rolling, fluffy hillocks and pits dotted with boulders and a few rocks. The moonlet rolled below the horizon less than a hundred meters away, except for a hill sticking up above it to the right. To the left he could see the automated lander with its volatile processing unit and drills on top; the solar arrays were mostly out of sight below the curve of the moonlet’s surface. Two pairs of long streaks showed where Sergei and Ethel had landed and bounced off the surface; a cloud of dust remained scattered in the vacuum, settling at an imperceptible rate. Walking was of debatable value, Will had thought.
“You’re better off flying,” said Sergei. All three of them had a camera on the top of their backpacks facing backwards and its tiny image was broadcast onto the visor near the top, where normally there would be nothing to look at. Sergei had seen him exit.
“He fell,” added Ethel.
“Okay; yes, I see the tracks his hands made.” Will floated in the door, holding onto a railing with one hand and onto two pointed aluminum poles in the other. They had made the “ski poles” on the interplanetary hab and hoped they would help. He decided to remind himself of the “flight rules” before embarrassing himself. Earth’s gravity accelerated objects at about 980 centimeters per second; Phobos, a mere 0.6 centimeter per second. That had advantages and disadvantages. It meant that the 140 kilograms of himself plus his suit had a weight of only 84 grams or three ounces; about three candy bars, not enough to walk on the surface without propelling oneself into the air. It was easier to use the maneuvering jets on his backpack, since they could be precisely controlled. They were calibrated so that pushing a button fired a particular jet enough to give him ten centimeters—four inches—per second of acceleration in the direction he desired. A vertical delta vee of ten centimeters per second would lift his feet almost a meter off the ground and return them to the surface 34 seconds later, but he could reach down with his ski poles to anchor himself almost any time. One meter per second of horizontal delta vee would carry him forward 34 meters; half that acceleration would carry him half as far, and he could always use his feet to “bounce” himself forward as well. That was the basic plan for moving around Phobos.
The lander was three hundred meters away, so he gave himself 10 centimeters per second of upward velocity and 1.5 meters per second of forward motion, the maximum advisable (for it was walking speed). And as he coasted he looked down at the fluffy, sandy regolith of the moon with the occasional mix of rocks. The surface had been pounded over the ages by micrometeorites, fragmenting the regolith into a powder devoid of most of its water and carbon. He could see colored bits as well; grains of nickel-iron meteorite, in particular.
There was a large rock about waist high sticking up ahead. Rather than coasting over it, Will reached down with both ski poles and sank them into the regolith using his forward motion, then allowed his feet to bounce off the rock. He had actually managed to stop without falling!
“Hey Will, a pretty neat maneuver!” said Ethel.
“Thank you; I’ve got to stop and look at this rock.” Will slowly pivoted his feet down to the ground and wiggled them into the powder to anchor himself. The maneuver worked fairly well. Then he suddenly realized that his “first words” on the moon were totally mundane. Oh well.
He pushed his feet into the powder more deeply, then leaned over and straightened up a few times to make sure the movement didn’t propel off the surface. The powder was enough of an anchor, fortunately.
He wrapped a stretchable cord around the rock and around his knees to anchor himself to it, then leaned over to look closely. He pulled out his rock hammer and tapped it a few times. Well anchored, he whacked the rock harder. Pieces broke off, but they flew everywhere.
“Rocks in orbit,” he mumbled. He got down on the ground and managed to find a very tiny fragment he had smashed loose. Then he looked at the exposed surface. It was a boulder of carbonaceous chondrite, as he expected; Phobos was made of the stuff. He dictated a detailed description of everything he saw and made sure his forward-facing helmet camera was activated to transmit its image. There were hundreds of geologists watching and they were counting on him to provide them with data.
He grabbed a scoop from his belt and picked up powdery regolith. He spent five minutes scooping, sifting through the fluff, separating out certain particles for later examination, and dictating a continuous description of what he saw. Sometime he went back and repeated parts of the description to add a detail he had forgotten; with a round trip communications time of nearly nine minutes, there was no opportunity for live questions. But he was careful to remain in one spot long enough for the questions to arrive. The geology desk at mission control vetted them and emailed them to him; they were displayed on the right side of his visor in such a way that he could look through them to the terrain outside. A few journalists’ questions were admitted as well and he went through the questions one by one; the geologists had noted a few things he had missed.
“Hey Will, when you look at something, you have to hold it a few seconds longer than you want, so we can look at it, too,” said David. He was following the expedition closely and commenting often.
“Thanks. I figure a lot of people are freezing the frames.”
“Maybe. The helmet camera is doing great, but sometimes an individual frame is blurred, so freezing the frame doesn’t always work.”
“Got it.”
Twenty minutes passed at the same spot before Will straightened up and disconnected the strap holding him to the rock. Sergei and Ethel had been working hard on driller number one, the drill that had gotten only ten meters into the moon because of a misplaced bolt. He conferred with them and, knowing they didn’t need a third set of hands, he flew to another boulder. After that he flew even farther, two-hundred fifty meters, to a crater that had punched through the dust to the rock beneath. There were exposed layers to look at on the side of a cliff, and one could hover in the vacuum with nothing more than a strap around a rock to help hold one still. The camera close-ups were the most interesting, though he did push a mesh bag against the cliff and hit it with his hammer; it propelled him out into space, but the mesh kept some of the pieces for close examination. For forty-five minutes he described crude layering, examined contacts, and debated what he saw. Fortunately there was a communications satellite in the sky that kept him in contact with the rest of the world.
“Will, we need your ski poles!” exclaimed Sergei.
“Oh? Okay, I’ll be right over. For what?”
“We’re trying to fish the rock fragments from shaft number two.”
“Okay.” Will glanced at his watch; he was surprised to see he had been outside for two hours. He could easily get immersed in geology. “What happened to drill number one?”
“Haven’t you been listening? It’s fixed. A robot couldn’t do it after months of trying, but two workers can do it in two hours. We’ll trigger it later and make sure it’s functioning.”
“I’m on my way.” Will looked around and momentarily couldn’t remember which way was which. So he fired his jets and shot upward at half a meter per second. In a bit less than minute he was twenty-five meters up and finally spotted the lander. He turned to face it and fired jets to head toward it. In five minutes he was there, managing a reasonably skillful landing on the metal surface.
“You’ve been doing a lot of geology!” exclaimed Ethel. “I’ve been eavesdropping a bit.”
“There’s a crowd out there waiting for every frame of the video and sending in their emailed questions. They can run me ragged, unless I put my foot down with mission control.”
“It’s one reason you’re a popular geologist; you don’t mind having the world looking over your shoulder,” said Sergei. He pointed. “You guys wedged the rock in here really good. But all the poles will fit together to make a boom long enough to push it downward.Maybe we can free it that way.”
“I went back to the ship and got the rest of them,” added Ethel. She had twelve more two-meter lengths with her.
They assembled eighteen segments together, making a single aluminum pole thirty-six meters long. The bottom pole had a sharp point; Sergei lowered it into the hole and slowly pushed it downward until it hit resistance.
“We need to be up there, pushing downward,” said Sergei, pointing to the open metal frame of the driller two meters above their heads. He pulled himself up the pole, then very slowly flipped himself upside down so that he could plant his feet against the frame. There was room for someone else; he beckoned Will up. Will followed him up the pole and planted his feet against the frame as well.
“Is your blood rushing to your head?” asked Ethel, amused to look at them upside down.
“You’d think our weight would be enough to dislodge the rock,” added Will.
“Never mind; are you ready?” asked Sergei. Will nodded. “Then let’s push!”
The two men began to shove the aluminum pole down the shaft with all the force their leg and back muscles could muster. The obstruction broke free suddenly and they plunged downward head first. Ethel had to reach up and break their falls. They tumbled downward, laughing.
“That must have done it,” said Sergei, sitting up. They all ended up on the ground, hands out to grab the powder and hold themselves in place. Will stood up by using his backpack’s jets. The three of them slowly got back up on the lander’s platform.
The three of them grabbed the broken cable and began to pull. The drill bit and a melted plastic sleeve full of cuttings came up easily; the cuttings flew everywhere, since there was nothing to confine them once they came out of the shaft.
“Alright!” exclaimed Sergei. “Let’s replace this cable and head back to the ship. I suspect we’ll find that both drills will be working fine.”
“Mission accomplished,” said Will.
© 2004 Robert H. Stockman