SPOT

The South Pole Overland Traverse (SPOT) arrived a few days ago.  It's more efficient in terms of gallons of fuel spent to drive fuel to the South Pole than it is to fly it in.  The station needs to have enough fuel by the end of the summer to sustain it through the winter (and usually has at least twice as much for safety).   So several times during the Antarctic summer, a convoy of tractor/trucks leaves McMurdo for the pole.    If you've ever watched the American TV show "Ice Road Truckers", this trip really puts it to shame.  Each tractor/truck pulls a enormous bladder of fuel.   One truck pulls a housing unit for the drivers.  The trucks are equipped with geological equipment so that they can safely avoid crevasses.  Along they way they cross the Trans-Antarctic mountains, and endure major snowstorms.  Imagine digging your car out of a 10 foot drift that completely covers it!  On average the traverse makes it about 30 miles a day and the whole trip (one-way) takes around a month.   The progress of the traverse is shown on the monitors in the galley, so we knew when they were getting close.  There was an announcement over the loudspeaker when they were about a 1/2 hour away and cleared to come down the landing strip.  Shortly after, we were able to see small, very slowly moving on the horizon. 

 We said goodbye to the second of our winter-overs last week.  While waiting for his plane to be ready,  I snapped a group photo of all the SPT people currently at pole.

 The receiver team has spent the last two days pulling apart the cryostat and focal plane (detectors) inside.  After a quick swap out of some detectors, they put it back together and back inside the receiver.  In the first picture, you can see the feedhorns that couples the light into the detectors that are directly underneath.  The second picture shows the back side of the entire assembly.  The nine silver and red towers sticking up above the gold ring are part of the readout electronics that we use to measure the signals on the detectors.   Working with the focal plane is a delicate task, and there was definitely a feeling of relief once it was back safely in the cryostat.  The plan is to close up the cryostat in the next day, and cool it back down to begin checking out the new detectors.  If all goes well, in a couple weeks it will be hoisted back up into the telescope cabin to begin new calibration measurements.

 As we were walking back from the telescope today for dinner, there was an amazing sun dog.  The idea is that the light refracts off  of ice crystals in the atmosphere, creating a halo effect.  There are always ice crystals in the atmosphere here, but a sun dog requires a vertical alignment.    Today's was particularly special because it was a double sun dog!