Today we took off on SOFIA for its second flight devoted 100% to measuring and characterizing the performance of the telescope and camera systems. It was very exciting for me to finally fly after working so long on the project. I was in charge of data quality control during the flight. We spent last week conducting line operations (we call them "line-ops"), using the observatory as if we were in flight but actually sitting on the ground. During the line-ops we practiced controlling the movement of the telescope with computer commands issued from the FORCAST camera. Juergen Wolf and his team from DSI and NASA/Ames also tested their new fine diagnostic camera (FDC), which can take visible light images at several hundred frames per second. For comparison, a movie or video camera usually records images 60 times per second. Why so fast? We wan't to "freeze" the star images, which move around in the telescope and camera viewers due to vibrations of the telescope and aircraft. Taking very fast movies in both visible (FDC) and infrared light (FORCAST) will allow the telescope team to understand in detail how the optical and telescope control systems are working. All of our testing so far indicates that the telescope and cameras are ready to go after a few small adjustments. Our first flight devoted to new astronomy (no more testing!) are scheduled for the week after Thanksgiving. 

Take-off time was 5:00 PM (Pacific Time) on Wednesday, November 10. The flight was scheduled to be 10 hours long, enough time for us to fly from LA to London, but instead we flew a back-and-forth flight plan as they did for the first light flight in May. Here's the flight plan from from last night's flight:

The flight began and ended at DAOF in Palmdale, CA (the white dot at the top of the map). The faint dotted outline in the upper right corner is the coast of southern California and Baja, Mexico. The light blue/green lines are the flight "legs" that add up to the full 10-hour flight plan. Each flight leg is plotted so that SOFIA can observe a particular object in the sky. For this flight the targets were bright stars that we used to test the cameras.

The flight crew including FORCAST team worked hard during the flight. This photo shows the FORCAST team working at the "PI Rack" that contains our camera control computer and the communication system that we use to communicate with one-another during the flight. Everyone wears headphones to reduce noise and enable efficient communication.