COSMOS was installed on the telescope before lunch.  During the afternoon we spent time trying to initialize the instrument so that we could take calibration data.  We were not able to take calibration during the day because of two problems we encountered; :(1) The instrument electronics box was installed on the wrong Blanco subnet (13 instead of 14) and (2) we had a loose fiber connection.  Neither of these problems were fixed before dinner.  After sunset, O. Estay and M. Martinez tested the new rotator and calibration lamp controls with the TCS.  We were able to move the rotator and control the lamps.

We spent part of the night taking normal calibration data.  The new hollow cathode CuHeAr lamp provides enough flux in a reasonable time period to be used during the night with the red grating.  We still lack sufficient counts using this lamp with the blue grating.  We took dome flat spectra at the old and the DECam white spots.  We found that using the DECam white spot gives higher counts using the same exposure times wrt the old white spot.   

We were able to successfully move the Cass rotator during the night.  We could not use the MOS alignment software to take images or spectra through the mask because the alignment software requires that the GCCROTAT keyword exists.  It was reported as "NA" all of the night.  We note that during the April COSMOS T&E time that the ROTATOR angle was being correctly reported in the headers.