Day 4 (Friday, Feb. 24)

After a few late evenings and with the prospect of a 4am launch to watch, we slept in today and showed up to the base in the afternoon…where we found out the launch is scrubbed (canceled)!  So that team's launch is slipping, and if everything checks out they'll probably go sometime next week instead.  We're scheduled to briefly return to California next week, so we might have to miss it.  :(

On the plus side, the alignment problem with most of our optics is fixed.  Our resourceful engineer Paul fashioned some small pieces (shims) to fit just underneath the piece that holds the optics in.  These are very thin pieces of varying thickness, so by placing them all around the optic you can ever so slightly change the angle of the optic so that it's pointing right onto the detector.  Getting the combination of pieces right and fitting them amongst all the other hardware on that fixture is not an easy task, and it took most of the day and evening yesterday. One optic has more severe problems and will need some more personal attention.

With that settled, we moved on to checking the alignment using X-rays instead of a laser.  For this test we built up the detector package (the cameras) on the telescope tube…this is the first time that the optics and detectors have been installed at the same time.  We then used a high-power X-ray generator to illuminate the optics and took an image of this.  The result was just what we wanted to see: an almost-perfect circle on the detector plane!  This is the first real FOXSI image and represents the culmination of years of work, and was especially gratifying for me to see since most of my efforts have been spent getting these detectors to work!