ISOTMAT: The balloon is a harsh mistress

Flight is your main method of travel in the Darksome Mire. Driving is too slow and too dangerous for long distances, and by my estimation, the Mire is about four million square miles if each screen represents one.

In theory, balloon flight is simple enough - ascend until you hit a good wind in the direction you want to go, stop ascending, and begin descent once you're close to the destination. In practice, this is made difficult for a few reasons.

• There's no way to view multiple instruments at once. You can view the direction you're headed with DIR, or you can view the direction you want to go with Hut1, but you can't view both at the same time.
  
• Ascending and descending are subject to inertia. When you switch off the burner, you don't stop ascending for a little while - same with venting and descending. You're likely to overshoot your desired altitude, requiring adjustment.
• Instrument updates are slow, especially radar and hut 1. But the balloon doesn't stop moving just because these are taking forever.
  
• Tools for reckoning your location are limited. The WHERE switch shows your sector, but this is only precise to 6,400 square miles/screens. Radar only shows points of interest in your current vicinity, and Hut 1 only shows the direction to the nearest hut wherever it may be. All of these instruments lag rather badly.
• The balloon naturally drifts while reaching your intended altitude, and the more time you spend making adjustments to get a steady altitude and direction, the longer and further it drifts. Same with descent.
  
• No visual flight; this craft is IFR-only, baby.

 

To aid flight, I did some test launches. Starting from the ground, I'd light the burner, shut it off at an altitude, and see where I stabilize at, and the resulting wind direction and speed. I tested this at each interval of 1000 feet.

Shutoff altitude	Stable altitude	Direction	Speed
1000	2950	202.5	2
2000	4200	326.25	11
3000	5100	45	18
4000	5800	90	20
5000	6500	123.75	24
6000	7100	202.5	30
7000	7750	202.5	32
8000	8400	225	35
9000	9200	315	41

 

All this testing drained much fuel; twice I had to search for more rocks, and once I had to abort a test and land early in order to rest. Thankfully, I did not encounter any crabs.

For the last test, I attempted to estimate landing drift by triangulating my bearing to the nearest hut, and estimated it to be about 9.5 miles from the moment I vent the balloon at 9200 feet to the moment I hit the ground.

Two readings and a bit of trig does it.

All this testing had blown me pretty far from Metallica too; the WHERE instrument read Q-12, putting me in another region and about 200 miles from home base.

I refueled and rechowed, during which I accidentally discovered a way to deal with crabs - evade until you encounter a visible longitudinal line, cross it, and then it dies attempting to cross itself. Then I put my chart to the test.

The nearest hut was about 75 degrees, so consulting the chart, I took the balloon upward and shut the burner off at 3,500 feet. It stabilized at 5,500. I checked the wind.

Not quite what I was hoping for, but it's in the right direction. I checked Hut 1.

Ah, shit. Rising drift threw me off! And apparently Terry was getting tired, because the word SLEEPY! starting flashing on the screen during the ascent and wouldn't stop, throwing off the keyboard input and making it a pain in the ass to do anything but drop down and go to bed.

Awakening, I found myself 96 miles from the hut at the same orientation as before - truly the way that drift works is bizarre, and perhaps I'm foolish to even try to defeat it in a methodical way. Nevertheless, I continued using my chart and launched again, shutting the burner off at 4,500 feet, which took me to 6,200.

Seems the relationship between altitude and wind direction is not a constant one! On the other hand, the relation between altitude and wind speed seemingly is - [Alt-2500]/160 usually gets me within 1 MPH of the wind speed.

From here I used DIR, not High, for guidance as I adjusted the burner to point the ship in the right direction, and once reasonably on-track, used Hut1 to gauge distance, and dropped once it showed a distance of 10 miles.

Eh, good enough for now.