With the gondola assembly essentially complete (the solar panels and the CSBF interface electronics are the major remaining systems to install), the past couple of days have featured less all-group work. Instead, our focus is turning towards our individual responsibilities, with a goal of getting the system running, tested, and flight ready as soon as we can.
Monday, we ran the coaxial ribbon cables that connect the detectors to their readout electronics into the electronics bay in the back of the gondola. The cables are fairly delicate, so this takes some care. Next week, one of our technicians from SSL will come to “harness” (or wrap) the cables in the ebay, which will protect them. Then we connected the detectors to the “card cages” which read them out and started up the system! Things are working, broadly, and now we’re checking that behavior of the electronics after their long road trip.
Others have been engaged in covering new parts in white paint–the white paint reflects sunlight (for things exposed to the sun) while making it radiate heat more efficiently in the infrared.
The differential GPS (dGPS) and flight computer are starting to take up my attention. I mounted the dGPS antennas in the corners of the gondola; hopefully they’ll be able to “see” satellites from inside the hangar.
One great success has been finishing thermal work on the flight computer. The flight computer CPU runs *very* hot, and at float altitudes (25 miles above the ground) there’s no air for fans to cool it. Accordingly we have to heat-sink it with metal conductors. We epoxied a large copper block to the CPU before we left SSL. Today the CSBF machine shop did a masterful (and *extremely quick*) job making a new front plate for the flight computer and a big aluminum block to pass heat to the front of the flight computer where it can radiate. Since that went so quickly, we should shortly be able to mount the flight computer and start running data through it. I’ll also resume critical work on the flight software…
Other highlights: Monday a few of us walked over to the other hangars to check out the other experiments flying during this campaign: Fireball (an ultraviolet telescope observing the intergalactic medium) and EBEX (a cosmic microwave background polarimeter). It was interesting to see the different approaches these experiments have taken, particularly to gondola design. Both experiments have gondolas easily twice as large as NCT’s, and Fireball’s is made of carbon fiber! (Enough for plenty of bicycles, that’s for sure.) Since there can be weather-related advantages to flying earlier (in addition to getting to go home sooner!) we emerged from our tour with additional motivation to get things running.
That said, the pace is a little easier these days, and there’s time for a break as needed.