May 21, 2009John MacKenty, STScI1 WFC3 SM4 Events and Current Status

May 21, 2009John MacKenty, STScI2 WFC3 Loaded in WSIPE August 2008 WFC3 was delivered to KSC in August 2008 –Final Functional test –Configured for flight (vent tubes) –Latches lubricated –Loaded into WSIPE Two trips to launch pad Monitoring of contamination witness mirrors

May 21, 2009John MacKenty, STScI3 SM4 Installation WFPC2 Removal –Undo Blind Mate Connector –Undo Ground Strap –Undo A-latch (could not be done with MTL – Drew did by hand) Not a “bolt” but a long mechanism Remove WFC3 from WSIPE –Open CCD and IR Vent Valves –Undo A-latch Install WFC3 into HST –Align with Guide Rails –Activate A-latch –Attach ground Strap –Activate Blind Mate Connector

May 21, 2009John MacKenty, STScI4 Aliveness and Functional Tests WFC3 Aliveness Test –Verified Side 1 and Side 2 Power; Side 2 command and data transfer WFC3 Functional Test –Basic verification of MEB2, CEB, DEB Suspend on DEB power-on due to known issue on unused voltage –Patched to generate status buffer message rather than Suspend –Verified CSM, FSM, SOFA, Shutter, and focus/alignment mechanisms –Powered on IR 6-Stage, UVIS 4-Stage, UVIS 2-Stage, and TECFIRE TECs Demonstrated nominal voltage&currents; observed 6-stage and 4-stage temp changes –Obtained 10 images 6 UVIS: Bias, 20s Dark, two “noise” images, two internal flat images 4 IR Images: Rapid dark, STEP25 dark, two “noise” (RESET) images –WFC3 fully passed FT for both UVIS and IR Channels!

May 21, 2009John MacKenty, STScI5 UVIS bias WFC3’s first orbital exposure

May 21, 2009John MacKenty, STScI6 UVIS dark Nominal Dark –“Scratches” exactly like ground data –Count rates reasonable Do not have ground data exactly at this temperature –Now we see COSMIC RAYS

May 21, 2009John MacKenty, STScI7 UVIS engineering noise, Amps AD & BC PRELIMINARY indication of expected 3.1 electrons read noise –Consistent with ground testing –This is a WARM measurement that tests signal chain

May 21, 2009John MacKenty, STScI8 UVIS F606W and F350LP tungsten lamp

May 21, 2009John MacKenty, STScI9 IR RAPID, NSAMP =7

May 21, 2009John MacKenty, STScI10 IR STEP25, NSAMP =7

May 21, 2009John MacKenty, STScI11 IR engineering images Warm test with continuous pixel reset –Provide some indication of readnoise –Appears unchanged from ground IR detector testing WARM demonstrates –Detector is alive (wire bonds OK) –Signal chain is OK

May 21, 2009John MacKenty, STScI12 Status Thermal –Cold plate VCHP radiator was running rather warm –Oscillations seen in Cold plate heater –Couple of adjustments to balance between cold plate heater and VCHP did not resolve oscillations (which were also seen in TV) –Changed configuration Wednesday afternoon Cold plate heater full on and VCHP controlling Appears to be stable at cost of Bench down 1 to 1.5 degrees WFC3 transition from Protect-Safe to Protect-Operate on Monday –Repeat of most of FT test plus memory and data buffer tests next week Wait until expiration of 21 day Detector Vent and BEA periods

May 21, 2009John MacKenty, STScI13 WFC3 RIU Temperatures this morning