Post on 03-Jan-2016
May 21, 2009 John MacKenty, STScI 2
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, 2009 John MacKenty, STScI 3
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, 2009 John MacKenty, STScI 4
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¤ts; 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, 2009 John MacKenty, STScI 6
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, 2009 John MacKenty, STScI 7
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, 2009 John MacKenty, STScI 11
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, 2009 John MacKenty, STScI 12
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