June 23, 2017
My first introduction to the land of Hobbits, is the refreshing rain on Friday June 23rd. Not to mention the cold and wind. With the first realization that maybe I needed more warm gear (she writes, despite her bags being full of fleeces and thermals). Nonetheless, my flask of hot tea, has indeed come to the rescue.
After disembarking from SOFIA, going through passport and customs control – I did make sure to toss all my nuts and raisins, and my boots passed inspection. Then a short hop to the hotel, a work telecom (almost on schedule) and I am surprisingly still awake to remember (there is a 19 hr time difference from California), and then some warm tea to warm the inner Kimberly and freshen up.
So I make my way down to the Antarctic Research Station, the homebase for SOFIA for these few months. I see the team hard at work, unpacking crates and boxes. We have three science instruments on this campaign, GREAT, FIFI-LS and FORCAST. GREAT was attached to the science instrument port on the telescope for the ferry-flight. FIFI-LS and FORCAST were placed in the cargo hold.
All of the infrared instruments need to be cooled such that their detectors can work appropriate and also the thermal radiation from the internal optics does not itself saturate the sensitive detectors. GREAT was transported in a warm configuration, so what happened today was to get it on the cryocooler, a mechanical cooling system (a refrigerator) to get down the instrument to 4 Kelvin.
SOFIA’s new capability for science instruments – cryocoolers on the upper deck.
The time it takes an instrument to cool down depends on the mass of the volume to be cooled. For the instruments on SOFIA, they typically need few days for the initial cooling from room temperature. Cooling of the GREAT instrument will occur aboard SOFIA and the other instruments are being transferred from their travel crates to their lab crates to make shift lab areas to get them ready when it’s there turn to fly.
GREAT getting a pump & cool down.
I hope to explore the city soon. Right now I am in total immersion in learning how the SOFIA team prepares for the first science flight.