2nd February 1995

From Michael Ashley.....

John tried an experiment today: he took two packets of biscuits (``cookies'' for our American readers) out to the Blue Building, one packet contained healthy recognisable natural ingredients, the other contained Oreos. By lunchtime all but two of the 45/46 Oreos were gone, and the other packet had not been touched.

Today is -39C, with bright blue sunny skies.

I should have mentioned that John got up at 5am and again at 8am to take the remaining two shots of our video sequence of sun shadows. Since we started trying to get these 3-hourly shots, the shadows have noticeably lengthened as the sun slowly sets.

Today was hugely successful with respect to IRPS. We cooled it down with LN2 using the automatic filling system, and it worked beautifully. The outer can filled in 15 minutes, and the inner can in 7 minutes, with hardly any loss of LN2. This is a huge improvement over filling it manually (which may take 45 minutes or so, and is quite tedious). Thanks must go to Peter Conroy of Mt. Stromlo who helped with the design of the filling wands.

Every time we turned on the ion pump, the current jumps to over 10mA, indicating a pressure worse than 10-4 torr. We attribute this to the molecular sieve still outgassing, and sure enough, after the inner can gets cold the ion pump suddenly starts to work properly and the pressure drops to 2x10-6 torr over the next few hours. It is very convenient to be able to read the dewar pressure from the computer - it will provide a good indication of the health of the dewar and allow us to diagnose problems. Writing the software to properly utilise all this information, and to take appropriate action if sensors fail, is quite a challenge. In total we have 18 sensors of various kinds (temperature, pressure, position) on IRPS.

John tries riding a bicycle to/from the Pomerantz Building, and finds that it is very strenuous work. When his cadence drops below about 65 the bike stops dead in its tracks, which is about the only way to stop since the bike doesn't have brakes. Changing gears is difficult since the gear-change cable sheath has fractured in the cold.

At 3pm all the CARA folk get together for a clean-up of the areas around the Pomerantz and Astro Buildings. Over the last couple of months there has been a steadily mounting collection of packing crates and assorted junk. All waste in Antarctica has to be carefully sorted into a multitude of categories, for example: plastic, white paper, burnables, wood, light metal, heavy metal, food waste, food contaminated materials, biological materials, aluminium cans, copper, and ``construction debris''. After an hour or so outside, we are all rather cold, but we have returned the environment back to pristine snow.

Jeff Peterson uses a metal detector to locate buried metallic objects. Unfortunately, the batteries die from the cold before he has gone 10 metres from the building. He retires inside to make an extension lead for the batteries so that he can keep them warm inside his parka.

We learn that there is only one aircraft on the continent that is capable of landing at the South Pole (the rest of them have various maintenance problems).