Resistors heat up. It's what they do.  There's my heat source.

I made and tested two “power loggers”, and confirmed the images were being properly recorded.

Then I had an EVA. I detached two of my solar cells and hooked them up to the power loggers. I let them log happily for an hour, then brought them back in to check the results. They worked great.

It's getting toward nightfall now. Tomorrow morning, I'll leave one power logger behind, and head south.

While I was working, I left the Oxygenator going (why not?). So I'm all stocked up on O2 and good to go.

The solar cell efficiency for today was 92.5%. Compared to yesterday's 97%. So right now, the storm is moving at 4.5% per sol. If I were to stay here another 16 sols, it would get dark enough to kill me.

Just as well I'm not going to stay here.

LOG ENTRY: SOL 478

Everything went as planned today. No hiccups. I can't tell if I'm driving deeper in to the storm or out of it. It's hard to tell if the ambient light is less or more than it was yesterday. The human brain works hard to abstract that out.

I left a power-logger behind when I started out. Then, after 40km travel due south, I had a quick EVA to set up another. Now I've gone the full 80km, set up my solar cells for charging, and I'm logging the wattage.

Tomorrow, I'll have to reverse course and pick up the power-loggers. It may be dangerous; I'll be driving right back in to a known storm area. But the risk is worth the gain.

Also, have I mentioned I'm sick of potatoes? Because, by God, I am sick of potatoes. If I ever return to Earth, I'm going to buy a nice little home in Western Australia. Because Western Australia is on the opposite side of Earth from Idaho.

I bring it up because I dined on a meal pack today. I had saved 5 packs for special occasions. I ate the first of them 29 sols ago when I left for Schiaparelli. I totally forgot to eat the second when I reached the half-way point 9 sols ago. So I'm enjoying my belated half-way feast.

It's probably more accurate to eat it today anyway. Who knows how long it'll take me to go around this storm. And if I end up stuck in the storm and doomed to die, I'm totally eating the other earmarked meals.

LOG ENTRY: SOL 479

Have you ever taken the wrong freeway entrance? You need to drive to the next exit to turn around, but you hate every inch of travel because you're going away from your goal.

I felt like that all day. I'm now back where I started yesterday morning. Yuk.

Along the way, I picked up the power-logger I'd left behind at the half-way point. Just now I brought in the one I'd left here yesterday.

Both loggers worked they way I'd hoped. I downloaded each of their video recordings to a laptop and advanced them to noon. Finally I had solar efficiency readings from three locations along an 80km line, all from the same time of day.

As of noon yesterday, the northern-most logger showed 12.3% efficiency loss, the middle one was a 9.5% loss, and the rover recorded a 6.4% loss at its southernmost location. It paints a pretty clear picture: the storm front runs northwest to southeast. And I already worked out it's traveling west.

The best way to avoid it is to go south.

Finally, some good news! South is what I wanted. I won't lose much time.

Sigh... I have to drive the same god damned path a third time tomorrow.

LOG ENTRY: SOL 480

I think I'm getting ahead of the storm.

Having traveled along Mars Highway 1 all day, I'm back at my campsite from yesterday. Tomorrow, I'll finally make real headway again. I was done driving and had the camp set up by noon. The efficiency loss here is 15.6%. Compared to the 17% loss at yesterday's camp, this means I can outrun the storm as long as I keep heading south.

Hopefully.

The storm is probably circular. They usually are. But I could just be driving in to an alcove. If that's the case, I'm just fucking dead, ok? There's only so much I can do.

I'll know soon enough. If the storm is circular, I should get better and better efficiency every day until I'm back to 100%. One I reach 100% that means I'm completely south of the storm and I can start going east again. We'll see.

If there were no storm, I'd be going directly southwest toward my goal. As it is, going only south, I'm not nearly as fast. I'm traveling 90km per day as usual, but I only get 37km closer to Schiaparelli because Pythagoras is a dick. I don't know when I'll finally clear the storm and be able to beeline to Schiaparelli again. But one thing's for sure: My plan to arrive on Sol 495 is boned.

Sol 549. That's when they come for me. If I miss it, I'll spend the rest of my very short life here. And I still have the MAV to modify before then, too.

Sheesh.

LOG ENTRY: SOL 482

Air day. A time for relaxation and speculation.

For relaxation, I read 100 pages of Agatha Christie's Evil Under the Sun courtesy of Johanssen's digital book collection. I think Linda Marshall is the murderer. 

As for speculation, I speculated on when the hell I'll get past this fucking storm.

I'm still going due south every day; and still dealing with efficiency loss (though I'm keeping ahead of it). Every day of this crap I'm only getting 37km closer to the MAV instead of 90. Pissing me off.

I considered skipping the Air Day. I could go another couple of days before I ran out of oxygen, and getting away from the storm is pretty important. But I decided against it. I'm ahead of the storm enough that I can afford one day of no movement. And I don't know if a couple more days would help. Who knows how far the storm goes south?

Well, NASA probably knows. And the news stations back on Earth are probably showing it. And there's probably a website like www.watch-mark-watney-die.com. So there's like a hundred million people or so who know exactly how far south it goes.

But I'm not one of them.

LOG ENTRY: SOL 484

Finally!

I am FINALLY past the god damned storm. Today's power regen was 100%. No more dust in the air. With the storm moving perpendicular to my direction of travel, it means I'm south of the southernmost point of the cloud (presuming it's a circular storm. If it's not then fuck.)

Starting tomorrow, I can go directly toward Schiaparelli. Which is good, cause I lost a lot of time. I went 540km due south while avoiding that storm. I'm catastrophically off course.

Mind you, it hasn't been that bad. I'm well in to Terra Meridiani now, and the driving is a little easier here than the rugged ass-kicking terrain of Arabia Terra. Schiaparelli is almost due east, and if my sextant and Phobos calculations are correct, I've got another 1030km to get there. 

Accounting for air days and presuming 90km of travel per sol, I should arrive on Sol 505. Not too bad, really. The Nearly-Mark-Killin' storm only ended up delaying me by 7 sols.