May 21, 2009 John MacKenty, STScI 1

WFC3 SM4 Events and Current Status

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&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, 2009 John MacKenty, STScI 5

UVIS biasWFC3’s first orbital exposure

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 8

UVIS F606W and F350LP tungsten lamp

May 21, 2009 John MacKenty, STScI 9

IR RAPID, NSAMP =7

May 21, 2009 John MacKenty, STScI 10

IR STEP25, NSAMP =7

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

May 21, 2009 John MacKenty, STScI 13

WFC3 RIU Temperatures this morning