Энди Вейр - The Martian

“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.”

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 16 thcentury 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.”

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?

I managed to thread the needle between Rutherford and Trouvelot nicely. Admittedly, the needle was a 100km wide, but hey.