Tuesday, January 21, 2003
Poodle for dinner
Ready for launch (almost)
Well, I'm still at Dome C. However I didn't get much done because I've already started to mentally disengage from the AASTINO, and shift into travelling mode.
The weather here is good, though a little overcast, with a remarkably high temperature of -19 C this afternoon. At McMurdo however, things continue to be crook. Our Twin Otter will probably leave for there around midnight tonight, although once I'm there it's unclear how long it will be until the C-141 is able to come and take me back to Christchurch. Although the Twin Otter can land on anything, the conditions have to be just right to satisfy the more finicky C-141. Even after a storm like this abates, it can apparently take up to two days to clear all the snow off the runway and the access roads.
About the only useful thing I did today was to help track down the missing 5 microsecond pulse. This is the pulse that the Supervisor sends every minute to the Wakey-wakey board to reassure it that it's still alive, thereby avoiding a premature burial. Watching for a pulse which is only 5 millionths of a second long and only occurs once every 60 seconds would normally try the patience of a saint. Fortunately, our multicolour multilingual all-singing all-dancing Tektronix oscilloscope takes such things in its stride, and did all the hard work for us.
To convince ourselves that the oscilloscope was actually watching out for pulses, we generated a few of our own by striking a wire across the terminal of a 9-volt battery. This led to a competition to see who could generate the shortest pulse. A few milliseconds was the norm, but I managed one lucky hit of 112 microseconds.
That was about it for me. After lunch I did some of the videoing I'd been too busy to do up until now, including some "Skidoo-cam" of variable success, and then went to bed.
Jon and Tony will fill you in with the real achievements of the afternoon, including putting the first 200 litres of fuel into our big tanks.
Dinner was the usual Jean-Louis triumph. Main course featured "lievre" which, judging by the size of the bones, was an animal about the size of a miniature poodle, but probably wasn't. Either way, it was delicious.
Crepes, hot from the pan and drizzled with Grand Marnier, finished things off nicely.
Today was my last day at Dome C (probably). The storm is till raging at McMurdo, but chances are it will move on tomorrow, and so will I.
For most of the day we checked out the various devices and sub-systems that we will depend on once Jon and Tony close the door to the AASTINO
at the beginning of February, and leave it to its own devices, so to speak, for the next nine months. Some of these things worked well - for example we can use the solar panels to charge the batteries, or we can switch that power to heat one of the instruments. Other things just plain didn't work, for example the pressure sensor that is supposed to let us know how much fuel is left in the tanks by measuring the "head" of fuel. However, we think all the "mission critical" things are now working.
We tested out our ingenious scheme for shutting down and restarting a recalcitrant engine control computer, but it was a bit of a disaster. I idea was a bit like that apparently used in nuclear-armed submarines: before anything as monumental as shutting off an engine can occur, both the webcam and the Dallas bus have to agree to do it. Then, we perform the electronic equivalent of pulling out a fuse, waiting a while, and putting it back. While our scheme worked exactly as planned, the effect on the Stirling engine was not good. We tried it on Nancy (we're leaving Sid to chug away continuously) and she threw a major tantrum, sending the display screen black, locking us out from remote control, and screeching shrilly via the beeper - and that was after we put the fuse back. Clearly, we don't quite know what we're doing here and we think we'll abandon this whole idea. I don't think the engine computer will crash, anyway.
A second scheme, for fooling the engine control computer into thinking the flame is still burning while we quickly shut off the fuel and reset the oxygen sensor, worked perfectly. You win some, you lose some.
For me this was a long and somewhat stressful day, trying to finish off the electronic control systems so that Jon and Tony can concentrate on the science instruments and on shaking down the engines. For Jon and Tony, tomorrow will be a chance to have some extra bench space and a spare coat-hook in the AASTINO. We've had a hell of a good time and, as the photos show, put a beaut little laboratory together. Let's hope it all works now. This will be my last diary from Dome C, but I'll try to send back a couple of reports of my journey home.
Dinner tonight include fresh waffles by Jean-Louis, a good way to conclude a stay at Dome C.