South Pole Diaries 1997/98

   

   


Saturday 22nd November 1997 - Taking things apart

From John Storey.....

We, and others, have mainly been taking things apart. Things are much less assembled than they were, say, 24 hours ago. Nevertheless, this is mainly a good thing.

A couple of emails ago, a few lines got deleted from the middle my message for reasons known only to the computer. I was saying that I thought it worthwhile to completely rebuild the electronics during 1998, as it has taked a real beating. We could take the opportunity to add a few refinements in order to make trouble-shooting easier.

Then for no apparent reason, the computer decided you'd had enough of that and cut straight to the middle of a story about how Ant had galantly climbed the G-tower and attached a pulley so we could haul the crane up. My musings about how cranes are wonderful apart from the fact that you have to get the crane up the tower in the first place got truncated.

Great big cranes need less big cranes,
Their altitude to heighten.

These little cranes need smaller ones,
And so ad infinitum.

(With apologies to the person who wrote something similar to explain microthermal turbulence and astronomical seeing, having ripped the idea off from someone who was talking about fleas.)

Anyway, to get the AFOS off the G-tower we need a crane, and the crane is no longer at the top of the tower because it was removed at the end of last summer (using gravity assist). So, we rigged up a rope and pulley and proceeded to the haul the crane up to the tower. About six inches. After a lot of aerobics we came to the conclusion that the task was physically impossible, and set off to find - yes, you've guessed it - a Sprite, so we could tie the rope onto the bumper bar (or equivalent) and haul it up. Fortunately we couldn't find a Sprite, which is a good thing, because the pulley was only tied to the hand rail and, as the Fluke pointed out, we would have simply pulled the handrail off the tower had we tried.

So that left us with the AFOS at the top of the tower and the crane at the bottom, when really we wanted it the other way round. We contemplated tying the rope aroung the AFOS, passing it through the pulley and using the crane as a counterweight, but only briefly.

It turns out there are two ways to get a big crane up a tower. One is to use a little crane, and the other is to use a REALLY BIG CRANE. It turned out that the station crane was going out to the dark sector yesterday evening to assemble an AMANDA drilling rig. It was therefore arranged that it would not only take GRIM down from SPIREX, put the Abu platform up on SPIREX, and put the G-tower crane on top.

It was supposed to come at 10pm but eventually started around 3am. By then I'd fallen asleep and took no part in the proceedings, but I don't think anyone noticed. Ant and the SPIREX crew worked till 4 and got the whole thing done.

This morning the AGO service crew arrived and started pulling the TEG apart. They are serious about getting it going, and have replaced the platinum beads and the thermoelectric modules. The TEG is spread over the entire floor of the AASTO. Ant and I have made a strategic retreat to the MAPO building until the atmospheric rockwool levels subside.

Now that the weather is a little better, Hercules flights have resumed. This makes life seem little more normal, as we're no longer isolated from the rest of the world. The South Pole program is weeks behind schedule, so they're scheduling 6 or 7 flights per day. However, typically only two are successful.

Because the Air National Guard are now flying the planes instead of VXE-6, the option of using JATO (Jet Assisted Take-Off) is now available again. Ev says they plan to use it on one of the upcoming AGO service missions. This is important to us as eventually we want to put the AASTO on the moon ^H^H^H^H Dome A.

Walter Tape is spending a few weeks here. He is the world expert on ice halos, and is continuing his studies this season. Maybe I already mentioned that.

Today the wind was down to 8 knots, so with the crane mounted atop the G-Tower we tackled the task of bringing the AFOS down. This was reasonably straightforward, but slow, cold and painful because the wind decided to pick up again as soon as we started. The AFOS is now sitting on a sled at the base of the tower, until such time as we can get some space in MAPO to disassemble it and pack it into a crate. I hope it doesn't rain tonight. For future reference, the nut that turns the crane is 1 1/8 inches. I mention this to save future generations of Antarctic astronomers the frustration of carrying half a workshop's worth of ring spanners up the tower, only to find that none of them fit.

Today we also discovered that the cable we need to instal to run Abu, and which was ordered weeks ago, is sitting in Yerkes. It is probably not very useful to them there. However, we've found a roll down here that will probably do instead.

The VIPER (Cosmic Microwave Experiment) was unpacked and it was discovered that the waveguide has sheared off the inputs to the preamplifiers, no doubt increasing their noise figure a tad. It's increasing unlikely that VIPER will run this year.

Another thing that's unlikely to run is the hard disk of the "super" computer. I plugged in the other 800MB drive and it made happy little disk humming noises. (This despite the fact that Ev Paschal who shall remain nameless *dropped* it off the shelf. Its fall was broken by the fact that it landed on the keyboard of my Mac. Note to mcba: Macs *do* have their uses) The super still wouldn't boot from it, but I didn't investigate further becaue the monitor wasn't plugged in. (It's in a plastic bag to keep the rockwool out of it). The noise it makes is quite unlike the mating-wasp noise the original one makes.

Ant volunteered for "house-mouse" duties today, and spent a couple of hours washing dishes. His skills were greatly admired by the cooks, with the result that I believe he will receive the runner-up award of house-mouse of the week. The cooks have given us a packet of bi-carb soda to fix our electronics with. They seemd to think this was perfectly normal, but then, we are at 10,000 feet.

Al Fowler and Nigel Sharpe didn't arrive today, which is just as well becasue we still have about a week's work to do before we're ready for them.

Micahel Ashley sent a sample of the stepper motor software to us, in reponse to our various unsubtle hints that it would be nice if a few little changes were made to it. This code, you'll recall was written by a professional programmer. I've come to the conclusion that professional house painters and professional programmers belong to the same union. Certainly the code looked like it had been written by a house painter, probably the one who painted our carport brown when we wanted it left white.

The section of stepper-motor code that worried me most was

If (someone is in the AASTO watching)

{ work properly};

Else

{ stuff up really badly }

Al Harper has asked to be kept informed of what we're doing here, so I will add him to this mailing list until such time as he screams for mercy.

John

 

 

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