Wednesday, August 27, 2008

Frozen

There are two primary factors that mark life here at pole as completely different from life in the real world. The first of these is the year-long day, with only a single sunrise and sunset per year. The second is the cold. I've gone on at length over the past four months about the night, but haven't delved too much into the many effects of the cold.

By and large, no machinery works cold. Anything with moving parts takes oil or grease, and there doesn't appear to be any grease which won't freeze solid by -90F. We aren't allowed to take vehicles outside below -80F, not for fear of damage to the engine - running keeps it warm enough - but because if stopped for any length of time they tend to freeze solid to the ground.

As far as SPT goes, the telescope's primary motors are kept warm inside the building (which is heated by waste heat from our electronics, supplemented with heat from the DSL furnace), while the smaller ones sit in the receiver cab on the end of the secondary arm, kept warm by a battery of electric heaters. Without heat, the telescope is dead in the water, just like everything else down here.

With that as preface, at 3am this past Sunday, the telescope lost power. The alarms failed, and Sunday is the one day of the week both Dana and I tend to sleep in a couple of hours. The telescope was without power for 6 hours before we discovered the problem, by which time, it was cold. Very cold. The building and main motors were slightly below freezing, while the entire receiver cab had dropped to -80F.

At that point, simply restoring the power wasn't an option - motors would turn back on and seize, hard drives would fail, fans would stall - in essence, everything breaks if powered up cold.

Instead, the cab needed to be reheated before powering anything back up. That set up a bit of a catch-22 - the heaters are electric, but we couldn't restore power until things were warm again. Worse, the fans on the heaters were all frozen, so powered heaters were likely to melt or catch fire.

Well, after much crawling in and out of the emergency hatch on the back of the cab (the main doors require the cab to be docked against the building, which in turn requires that the motors in the cab be functional), flipping breakers, disconnecting electronics, and fiddling with heaters, we finally got things warming up. Six hours later, the cab was up to freezing, and we were able to begin turning stuff back on.

Several systems came online relatively easily, while others did not. Some metals' resistances drop precipitously when deep frozen, with the result that several of our external heating systems cannot be turned on cold - if you try, they draw too much current and trip a breaker. They work fine once warm, but again, that makes for somewhat of a catch-22. Many of our electronics failed to initialize properly cold, and had to be reset several times as they gradually warmed up from different systems coming online.

Last night at 3am, fully four days after losing power, we finally got everything back online and were able to resume normal observations. It's been a hectic week, all because an alarm didn't go off, and the temperature outside was so cold. This is the sort of thing that makes life and work down here so different from the real world.

With everything back online, it's been amazing to look up from our work and suddenly realize how bright it's been getting outside. The sunrise is starting to feel rather imminent.

1 comment:

desert tortise said...

Isn't this what I just read about in the Antarctic Sun? Way to go!