by Andy Weir
off-script now. Just keep it from interfering with your duties and I'm happy.”
“Million-mile-high club,” Martinez said. “Nice!”
Johanssen blushed deeper and buried her face in her hands.
LOG ENTRY: SOL 444
I'm getting pretty good at this. Maybe when all this is over I could be a product-tester for Mars rovers.
Things went well. I spent five sols driving in circles; I averaged 93 km per sol. That's a little better than I'd expected. The terrain here is flat and smooth, so it's pretty much a best-case scenario. Once I'm going up hills and around boulders it won't be nearly that good.
The bedroom is awesome. Large, spacious, and comfortable. On the first night, I ran in to a little problem with the temperature. It was fucking cold. The rover and trailer regulate their own temperatures just fine, but things weren't hot enough in the bedroom.
Story of my life.
The rover has an electric heater that pushes air with a small fan. I don't use it for anything because the RTG provides all the heat I need. I liberated the fan and wired it in to a power line near the airlock. Once it had power all I had to do was point it at the bedroom.
It's a low-tech solution, but it worked. There's plenty of heat, thanks to the RTG. I just needed to get it evenly spread out. For once, entropy was on my side.
I fell in to a routine pretty quickly. In fact, it was hauntingly familiar. I did it for 22 miserable days on the Pathfinder trip. But this time, I had the bedroom and that makes all the difference. Instead of being cooped up in the rover, I have my own little Hab.
The procedure is what you'd expect. After waking up, I have a potato for breakfast. Then, I deflate the bedroom from the inside. It's kind of tricky, but I worked out how.
First, I put on an EVA suit. Then I close the inner airlock door, leaving the outer door (which the bedroom is attached to) open. This isolates the bedroom, with me in it, from the rest of the rover. Then I tell the airlock to depressurize. It thinks it's just pumping the air out of a small area, but it's actually deflating the whole bedroom.
Once the pressure is gone, I pull the canvas in and fold it. Then I detach it from the outer hatch and close the outer door. This is the most cramped part. I have to share the airlock with the entire folded up bedroom while it repressurizes. Once I have pressure again, I open the inner door and more-or-less fall in to the rover. Then I stow the bedroom, and go back to the airlock for a normal egress to Mars.
It's a complicated process, but it detaches the bedroom without having to depressurize the rover cabin. Remember, the rover has all my stuff that doesn't play well with vacuum.
The next step is to gather up the solar cells I'd laid out the day before and stow them on the rover and trailer. Then I do a quick check on the trailer. I go in through its airlock and basically take a quick look at all the equipment. I don't even take off my EVA suit. I just want to make sure nothing's obviously wrong.
Then, back to the rover. Once inside, I take off the EVA suit and start driving. I drive for almost 4 hours, and then I'm out of power.
Once I park, it's back in to the EVA suit for me, and out to Mars again. I lay the solar panels out and get the batteries charging.
Then I set up the bedroom. Pretty much the reverse of the sequence I use to stow it. Ultimately it's the airlock that inflates it. In a way, the bedroom is just an extension of the airlock.
Even though it's possible, I don't rapid-inflate the bedroom. I did that to test it because I wanted to find where it'll leak. But it's not a good idea. Rapid inflation puts a lot of shock and pressure on it. It would eventually rupture. I didn't enjoy that time the Hab launched me like a cannonball. I'm not eager to repeat it.
Once the bedroom is set up again, I can take off my EVA suit and relax the rest of the day. I mostly watch crappy 70's TV. I'm indistinguishable from an unemployed guy for most of the day.
I followed that process for four sols, and then it was time for an “Air Day”.
An Air Day turns out to be pretty much the same as any other day, but without the 4 hour drive. Once I set up the solar panels, I fired up the Oxygenator and let it work through the backlog of CO2 the Regulator had stored up.
Once it was done, my test run was complete. It converted all the CO2 to oxygen, and used up the day's power generation to do it.
The test was a success. I'll be ready on time.
LOG ENTRY: SOL 449
Today's the big day. I'm leaving for Schiaparelli.
The rover and trailer are all packed. They've been mostly packed since the test run. But now I even have the water aboard.
I spent the last several days running full diagnostics on everything. The Regulator, Oxygenator, RTG, AREC, batteries, rover life support (in case I need a backup), solar cells, rover computer, airlocks, and everything else with a moving part or electronic component. I even checked each of the motors. Eight in all, one for each wheel, four on the rover, four on the trailer. The trailer's motors won't be powered, but it's nice to have backups.
It's all good to go. No problems that I can see.
The Hab is a shell of its former self. I've robbed it of all critical components and a big chunk of its canvas. I've looted that poor Hab for everything it could give me, and in return it's kept me alive for a year and a half. It's like The Giving Tree.
I performed the final shutdown today. The heaters, lighting, main computer, etc. All the components I didn't steal for the trip to Schiaparelli.
I could have left them on. It's not like anyone would care. But the original procedure for Sol 31 (which was supposed to be the last day of the surface mission) was to completely shut down the Hab and deflate it. NASA didn't want a big tent full of combustible oxygen next to the MAV when it launched, so they added the shutdown process to the mission.
I guess I did it as an homage to the mission Ares 3 could have been. A small piece of the Sol 31 I never got to have.
Once I shut everything down, an eerie silence was all that remained. I've spent 449 sols listening to the heaters, vents, and fans. But now it was dead quiet. It's a creepy, eerie kind of quiet that's hard to describe. I've been away from the Hab before, but always in the rover or an EVA suit. There's always some kind of machinery in operation.
But now there was nothing. I never realized how utterly silent Mars is. It's a desert world with practically no atmosphere to convey sound. I could hear my own heartbeat.
Anyway, enough waxing philosophical.
I'm in the rover right now. (That should be obvious, with the Hab main computer offline forever.) I've got 2 full batteries, all systems are go and I've got 45 sols of driving ahead of me.
Schiaparelli or bust!
Chapter 22
LOG ENTRY: SOL 458
Mawrth Vallis! I'm finally here!
Actually, it's not an impressive accomplishment. I've only been traveling 10 sols. But it's a good psychological milestone.
So far, the rover and my ghetto life support are working admirably. At least, as well as can be expected for equipment being used ten times longer than intended.
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 could
n'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 i
n 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.”