by Энди Вейр
Today is my second Air Day (the first was 5 sols ago). When I put this scheme together, I figured Air Days would be godawful boring. But now I look forward to them. They’re my days off.
On a normal day I get up, fold up the bedroom, stack the solar cells, drive four hours, set up the solar cells, unfurl the bedroom, check all my equipment (especially the rover chassis and wheels), then make a Morse Code status report for NASA if I can find enough nearby rocks.
On an Air Day, I wake up and turn on the Oxygenator. The solar panels are already out from the day before. Everything’s ready to go. Then I chill out in the bedroom or rover. I have the whole day to myself. The bedroom gives me enough space that I don’t feel cooped up, and the computer has plenty of shitty TV reruns for me to enjoy.
Technically, I entered Mawrth Vallis yesterday. But I only knew that by looking at a map. The entrance to the valley is wide enough that I couldn’t see the canyon walls in either direction.
But now I’m definitely in a canyon. And the bottom is nice and flat. Exactly what I was hoping for. It’s amazing; this valley wasn’t made by a river slowly carving it away. It was made by a mega-flood in a single day. It would have been a hell of a thing to see.
Weird thought: I’m not in Acidalia Planitia any more. I spent 457 sols there, almost a year and a half, and I’ll never go back. I wonder if I’ll be nostalgic about that later in life.
If there is a “later in life,” I’ll be happy to endure a little nostalgia in return. But for now I just want to go home.
“Welcome back to CNN’s Mark Watney Report,” Cathy said to the camera. “We’re speaking with our frequent guest, Dr. Venkat Kapoor. Dr. Kapoor, I guess what people want to know is: Is Mark Watney doomed?”
“We hope not,” Venkat responded. “But he’s got a real challenge ahead of him.”
“According to your latest satellite data, the dust storm in Arabia Terra isn’t abating at all, and will block 80% of the sunlight?”
“That’s correct.”
“And can Watney’s only source of energy is his solar panels, correct?”
“Yes, that’s right.”
“Can his makeshift rover operate at 20% power?”
“We haven’t found any way to make that happen, no. His life support alone takes more energy than that.”
“How long until he enters the Tau Event.”
“He’s just entered Mawrth Vallis now. At his current rate of travel, he’ll be at the edge of the Tau Event on Sol 471. That’s 12 days from now.”
“Surely he’ll see something is wrong,” Cathy said. “With such low visibility, it won’t take long for him to realize his solar cells will have a problem. Couldn’t he just turn around at that point?”
“Unfortunately, everything’s working against him,” Venkat said. “The edge of the storm isn’t a magic line. It’s just an area where the dust gets a little more dense. It’ll keep getting more and more dense as he travels onward. It’ll be really subtle; every day will be slightly darker than the last. Too subtle to notice.”
Venkat sighed. “He’ll go hundreds of kilometers, wondering why his solar panel efficiency is going down, before he’s notices any visibility problems. And the storm is moving west as he moves east. He’ll be too deep in to get out.”
“Are we just watching a tragedy play out?” Cathy asked.
“There’s always hope,” Venkat said. “Maybe he’ll figure it out faster than we think and turn around in time. Maybe the storm will dissipate unexpectedly. Maybe he’ll find a way to keep his life support going on less energy than we thought was possible. Mark Watney is now an expert at surviving on Mars. If anyone can do it, it’s him.”
“Twelve days,” Cathy said to the camera. “All of Earth is watching, but powerless to help.”
LOG ENTRY: SOL 462
Another uneventful sol. Tomorrow is an Air Day, so this is kind of my Friday night.
I’m about half-way through Mawrth Vallis now. Just as I’d hoped, the going has been easy. No major elevation changes. Hardly any obstacles. Just smooth sand with rocks smaller than half a meter.
You may be wondering how I navigate. When I went to Pathfinder, I watched Phobos transit the sky to figure out the east-west axis. But Pathfinder was an easy trip compared to this, and I did it mostly with landmarks.
I can’t get away with that this time. My “map” (such as it is) consists of satellite images far too low-resolution to be of any use. They just never expected me to be out this far. The only reason I had high-res images of the Pathfinder region is because they were included for landing purposes; in case Martinez had to land way long of our target.
So this time around, I needed a reliable way to fix my position on Mars.
Latitude and Longitude. That’s the key. The first is easy. Ancient sailors on Earth figured that one out right away. Earth’s 23.5 degree axis points at Polaris. Mars has a tilt of just over 25 degrees, so it’s pointed at Deneb.
Making a sextant isn’t hard. All you need is a tube to look through, a string, a weight, and something with degree markings. I made it in under an hour.
So I go out every night with a home-made sextant and sight Deneb. It’s kind of silly if you think about it. I’m in my space suit on Mars and I’m navigating with 16th century tools. But hey, they work.
Longitude is a different matter. On Earth, the earliest way to work out longitude required them to know the exact time, then compare it to the sun’s position in the sky. The hard part for them back then was inventing a clock that would work on a boat (pendulums don’t work on boats). All the top scientific minds of the age worked on the problem.
Fortunately, I have accurate clocks. There are four computers in my immediate line of sight right now. And I have Phobos.
Because Phobos is ridiculously close to Mars, it orbits the planet in less than one Martian day. So it travels west to east (unlike the sun and Deimos) and sets every 11 hours. And naturally, it moves in a very predictable pattern.
I spend 13 hours every sol just sitting around while the solar panels charge the batteries. Phobos is guaranteed to set at least once during that time. I note the time when it does. Then I plug it in to a nasty formula I worked out and I know my longitude.
So, working out longitude requires Phobos to set, and working out latitude requires it to be night so I can sight Deneb. It’s not a very fast system. But I only need it once a day. I work out my location when I’m parked, and account for it in the next day’s travel. It’s kind of a successive approximation thing. So far, it’s been working.
Mindy Park zoomed in on the latest satellite photo with practiced ease. Watney’s encampment was visible in the center, the solar cells laid out in a circular pattern as was his habit.
The bedroom was inflated. Checking the timestamp on the image, it was from noon local time. She quickly found the status report; Watney always placed it close to the rover when rocks were in abundance, usually to the north.
To save time, Mindy had taught herself Morse Code so she wouldn’t have to look each letter up every morning. Opening an email, she addressed it to the ever-growing list of people who wanted Watney’s daily status message.
“ON TRACK FOR SOL 495 ARRIVAL.”
She frowned and added “Note: 5 sols until Tau Event entry.”
LOG ENTRY: SOL 466
Mawrth Vallis was fun while it lasted. I’m in Arabia Terra now.
I just entered the edge of it, if my latitude and longitude calculations are correct. But even without the math, it’s pretty obvious the terrain is changing.
For the last two sols, I’ve spent almost all my time on an incline, working my way up the back wall of Mawrth Vallis. It was a gentle rise, but a constant one. I’m at a much higher altitude now. Adicalia Planitia (where the lonely Hab is hanging out) is 3000m below elevation zero, and Arabia Terra is 500m below. So I’ve gone up two and a half kilometers.
Want to know what’s at elevation zero? On Earth, it’s sea level. Obviously, that
won’t work on Mars. So lab-coated geeks got together and decided Mars’s elevation zero is wherever the air pressure is 610.5 Pascals. That’s about 500 meters up from where I am right now.
Now things get tricky. In Acidalia Planitia, if I got off-course, I could just point in the right direction based on new data. Later, in Mawrth Vallis, it was impossible to fuck it up. I just had to follow the canyon.
Now I’m in a rougher neighborhood. The kind of neighborhood where you keep your rover doors locked, and never come to a complete stop at intersections. Well, not really, but it’s bad to get off-course here.
Arabia Terra has large, brutal craters that I have to drive around. If I navigate poorly, I’ll end up at the edge of one. I can’t just drive down one side and up the other. Rising in elevation costs a ton of energy. On flat ground, I can make 90km per day. On a steep slope, I’d be lucky to get 40km. Plus, driving on a slope is dangerous. One mistake and I could roll the rover. I don’t even want to think about that.
Yes, I’ll eventually have to drive down in to Schiaparelli. No way around that. I’ll have to be really careful.
Anyway, if I end up at the edge of a crater I’ll have to backtrack to somewhere useful. And it’s a damn maze of craters out here. I’ll have to be on my guard; observant at all times. I’ll need to navigate with landmarks as well as latitude and longitude.
My first challenge is to pass between the craters Rutherford and Trouvelot. It shouldn’t be too hard. They’re 100km apart. Even I can’t fuck that up, right?
Right?
LOG ENTRY: SOL 468
I managed to thread the needle between Rutherford and Trouvelot nicely. Admittedly, the needle was a 100km wide, but hey.
I’m now enjoying my fourth Air Day of the trip. I’ve been on the road for 20 sols. So far, I’m right on schedule. According to my maps, I’ve traveled 1,440km. Not quite halfway there, but almost.
I’ve been gathering soil and rock samples from each place I camp. I did the same thing on my way to Pathfinder. But this time, I know NASA’s watching me. So I’m labeling each sample by the current sol. They’ll know my location a hell of a lot more accurately than I do. They can correlate the samples with their locations later.
It might be a wasted effort. The MAV isn’t going to have much weight allowance when I launch. To intercept Hermes, it’ll have to reach escape velocity, but it was only designed to get to orbit. The only way to get it going fast enough is to lose a lot of weight.
At least that jury-rigging will be NASA’s job to work out, not mine. Once I get to the MAV, I’ll be back in contact with them and they can tell me what modifications to make.
They’ll probably say “Thanks for gathering samples. But leave them behind. And one of your arms, too. Whichever one you like least.” But on the off-chance I can bring them, I’m gathering them.
The next few days travel should be easy. The next major obstacle is Marth Crater. It’s right in my straight-line path toward Schiaparelli. It’ll cost me a hundred kilometers or so to go around, but it can’t be helped. I’ll try to aim for the southern edge. The closer I get to the rim the less time I waste going around it.
“Did you read today’s updates?” Lewis asked, pulling her meal from the microwave.
“Yeah,” Martinez said, sipping his drink.
She sat across the Rec table from him. Carefully opening the steaming package, she let it cool for a moment before eating. “Mark entered the dust storm yesterday.”
“Yeah, I saw that,” he said.
“We need to face the possibility that he won’t make it to Schiaparelli,” Lewis said. “If that happens, we need to keep morale up. We still have a long way to go before we get home.”
“He was dead before,” Martinez said. “It was rough on morale, but we soldiered on. Besides, he won’t die.”
“It’s pretty bleak, Rick,” Lewis said. “He’s already 50km in to the storm, and he’ll go another 90km per sol. He’ll get in too deep to recover soon.”
Martinez shook his head. “He’ll pull through, Commander. Have faith.”
She smiled forlornly. “Rick, you know I’m not religious.”
“I know,” he said. “I’m not talking about faith in God, I’m talking about faith in Mark Watney. Look at all the shit Mars has thrown at him, and he’s still alive. He’ll survive this. I don’t know how, but he will. He’s a clever son-of-a-bitch.”
Lewis took a bite of her food. “I hope you’re right.”
“Want to bet $100?” Martinez said with a smile.
“Of course not,” Lewis said.
“Damn right,” he smiled.
“I’d never bet on a crewmate dying,” Lewis said. “But that doesn’t mean I think he’ll-”
“Blah blah blah,” Martinez interrupted. “Deep down, you think he’ll make it.”
LOG ENTRY: SOL 473
My fifth Air Day, and things are going well. I should be skimming south of Marth Crater tomorrow. It’ll get easier after that.
I’m in the middle of a bunch of craters that form a triangle. I’m calling it the Watney Triangle because after what I’ve been through, shit on Mars should be named after me.
Trouvelot, Becquerel, and Marth form the points of the triangle, with 5 other major craters along the sides. Normally this wouldn’t be a problem at all, but with my extremely rough navigation, I could easily end up at the lip of one of them and have to backtrack.
After Marth, I’ll be out of the Watney Triangle (yeah, I’m liking that name more and more). Then I can beeline toward Schiaparelli with impunity. There’ll still be plenty of craters in the way, but they’re comparatively small and going around them won’t cost much time.
Progress has been great. Arabia Terra is certainly rockier than Acidalia Planitia, but nowhere near as bad as I’d feared. I’ve been able to drive over most of the rocks, and around the ones that are too big.
I have 1435km left to go. Ares 4’s MAV is in the southwest part of Schiaparelli. The primary goal of Ares 4 is to get a look at the long-term effects of Martian weather on deep layers of strata exposed by the crater.
At least, that was the original plan. I’ll be taking their MAV and Commander Lewis hasn’t given Hermes back, so we’ve ruined everything. They’ll probably just send another MAV and wait for the next window.
I did some research on Schiaparelli and found some good news. The best way in is right in my direct-line path. I won’t have to drive the perimeter at all. And the way in is easy to find, even when you suck at navigating. The northwest rim has a smaller crater on it, and that’s the landmark I’ll be looking for. To the southwest of that little crater is a gentle slope in to Schiaparelli Basin.
The little crater doesn’t have a name. At least, not on the maps I have. So I dub it “Entrance Crater.” Because I can.
In other news, my equipment is starting to show signs of age. Not surprising, considering it’s way the hell past its expiration date. For the past two sols, the batteries have taken longer to recharge. The solar cells just aren’t producing as much wattage as before. It’s not a big deal, I just need to charge a little longer.
LOG ENTRY: SOL 474
Well, I fucked it up.
It was bound to happen eventually. I navigated badly and ended up at the ridge of Marth Crater. With it being 100km wide, I can’t see the whole thing, so I don’t know where on the circle I am.
The ridge runs perpendicular to the direction I was going. So I have no clue which way I should go. And I don’t want to take the long way around if I can avoid it. Originally I wanted to go around to the south, but north is just as likely to be the best path now that I’m off-course.
I’ll have to wait for another Phobos transit to get my longitude, and I’ll need to wait for nightfall to sight Deneb for my latitude. So I’m done driving for the day. I’d made 70km out of the 90km I usually do. So it’s not too much wasted potential driving.
Marth isn’t too steep. I could probably just drive down one side and up the
other. It’s big enough that I’d end up camping inside it one night. But I don’t want to take unnecessary risks. Slopes are bad and should be avoided. I gave myself plenty of buffer time, so I’m going to play it safe.
I’m ending today’s drive early and setting up for recharge. Probably a good idea anyway with the solar cells acting up; it’ll give them more time to work. They underperformed again last night. I checked all the connections and made sure there wasn’t any dust on them, but they still just aren’t 100%.
LOG ENTRY: SOL 475
I’m in trouble.
I watched two Phobos transits yesterday and sighted Deneb last night. I worked out my location as accurately as I could, and it wasn’t what I wanted to see. As far as I can tell, I hit Marth Crater dead-on.
Craaaaap.
This is the worst case scenario. I can go north or south, and they’ll be about the same. It’ll cost at least a day to correct. All because I aimed wrong yesterday.
That’s frustrating, but it’s not why I’m in trouble.
I still wanted to be efficient, and I wasn’t 100% sure where I was. So I took a little walk this morning. It was over a kilometer to the peak of the rim. That’s the sort of walk people do on Earth without thinking twice, but in an EVA suit it’s an ordeal.
I can’t wait till I have grandchildren. “When I was younger, I had to walk to the rim of a crater. Uphill! In an EVA suit! On Mars, ya little shit! Ya hear me? Mars!”
Anyway, I got up to the rim and damn, it’s a beautiful sight. From my high vantage point, I got a stunning panorama. I figured I might be able to see the far side of Marth Crater, and maybe work out if north or south was the best way around it.
But I couldn’t see the far side. There was a haze in the air. It’s not uncommon; Mars has weather and wind and dust, after all. But it seemed hazier than it should. I’m accustomed to the wide-open expanses of Acidalia Planitia, my former prairie home.
Then it got weirder. I turned around and looked back toward the rover and trailer. Everything was where I’d left it (very few car thieves on Mars). But the view seemed a lot clearer.