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Wednesday, October 24, 2007: Ye Olde Leaky ROV
We've been having the good kind of pressure leaks the past couple days: the slow predictable kind with no permanent damage. While testing the electronics bottle for our backup SCINI, we found water repeatedly leaking in around our "waterproof" connectors. Usually we're worried about leaks caused by dirt and hairs around our rubber O-rings, but as we've demonstrated it's worth testing the usually reliable connectors as well.


One we determined we had a leak near our connectors by checking the dampness of different paper towels arrayed around the inside surface of our otherwise empty electronics bottle, we reversed the usual pressure and pumped up the air inside the bottle. Submerged underwater, the bubbles streaming out identified the culprit connector quickly. It's a lot easier to look for flowing bubbles on the outside of the bottle than for tiny drops of water on the inside of the bottle because usually the drops spray or get shaken around before we can inspect them.

To give an idea of the forces involved, our bottle lids have a surface area of about 30 square inches (193.5 square centimeters) and we inflated the bottle with air to a relative 5 psi (pounds per square inch); that means each lid had the equivalent of 150 pounds (68 kilograms at Earth's surface, or 667.2 newtons) of force spread across them, pushing outwards. Ultimately we would like SCINI to dive to a thousand feet (305 meters), where the pressure reaches about 425 psi; this works out to 12,750 pounds (5,783 kilograms at Earth's surface, 56,714 newtons) spread out over our thin little plastic lids... if that force was applied to my body (in a vacuum), I would break the sound barrier in less than half a second.

After sending down our troublesome bottle for a (final?) supper time pressure test in one of our dive huts, Mindy and I stopped by the old science aquarium, where marine work used to get done before our our modern spaceship/science complex was constructed a few years ago.

We were looking for an open tank we could use to rinse off SCINI after dives while we're in the field next week near New Harbor; Mindy made a very somber ruler.

Even though it's still used by a number of groups, the old aquarium reminded me of Scott's hut: cozy, lots of notes and warnings handwriten on the walls, piled up snow, and an efficent degree of disorganization.

The past few days have mostly been snowy and desaturated, but the snow blows away every now and then for us to see a new kind of sunset, like this one tuesday night. Tonight was snowier when Marcus and I went back out to recover the electronics bottle from it's final test. The snow here has a consistancy unlike any other, I think it's kind of like really good ricotta cheese, only lighter and stonger like aerogel. Either way, the bottle was bone dry inside, so we can go forward with our packing tomorrow!

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This material is based on work supported by the National Science Foundation under Grant No. ANT-0619622 ( Any opinions, findings and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation.