Wide Field Camera 3
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Project Updates 2002


The flight unit WFC3 Thermo-Electric Cooler For Infrared (IR) Electronics (TECFIRE) has been assembled.

The WFC3 optical assembly was shipped from Ball Aerospace and arrived at GSFC during the middle of the week.

Both channels had successfully completed optical alignment and encircled energy measurement. Integration and test of the WFC3 instrument will be performed at GSFC.


WFC3 Thermo-Electric Cooler For Infrared Electronics (TECFIRE) design has successfully completed qualification environmental testing for both the Cold Enclosure (CE) and the Detector Base (DB) configurations.

The WFC3 Ultra-violet Visible (UVIS) encircled energy testing was successfully completed.

The GSFC Detector Characterization Lab (DCL) completed the analysis and comparison of the WFC3 Ultraviolet Visible channel Charge Injection (CI) versus pre-flash operation for mitigating charge transfer efficiency degradation.


Repositioning of the WFC3 Refractive Corrector Plate (RCP) on the 6-stage of freedom mount achieved significant improvement in the IR channel encircled energy.

The WFC3 Thermo-Electric Cooler For InfraRed Electronics (TECFIRE) engineering units are nearly through their Thermal Vacuum (TV) qualification tests. Preliminary results show that performance exceeds expectations.


The WFC3 Ultra-violet Visible (UVIS) and Infrared (IR) Detector Electronics Boxes completed their final functional tests and are ready to be delivered to GSFC.

TECFIRE Single Assembly Engineering Unit successfully underwent vibration and vacuum testing.


Ultraviolet Visible (UVis) and Infrared surrogate detectors and the cold assembly have been integrated onto the optical bench.

Ball Aerospace completed Printed Wiring Assembly testing on WFC3's Charge-Coupled Device (CCD), Electronics Box (CEB), and Detector Electronics Box (DEB).

The thermal blanketing has been installed on the WFC3 stimulus.


WFC3 UVIS Flight Detector has completed 3 of 4 planned thermal cycles without issue. The final cycle is scheduled for this week.

The WFC3 Infrared (IR) flight detector ghost baffles were successfully assembled and aligned on the IR detector assembly.

The WFC3 Ultra-violet Visible (UVIS) flight detector assembly is undergoing thermal cycling at Ball. Alignment activities will continue after completion of thermal cycling.


Flight IR detector #50 hand-carried to Ball for IR Build 1. Subsequently experienced overtemperature event during wire bonding and downgraded to non-flight.

TECFIRE redesign continues.

IR filter wheel completed (all filters installed).

Pinholes (re)discovered in UV filter 275W after environmental testing at Moog. Investigation started and plans being made for replacement or painting. Subsequent discussions concluded that the holes have negligible scientific impact, were always there, and will most likely not get worse. Proceeding as-is.

Stimulus being retested after reconstruction in the HST SSDIF clean room.


TECFIRE performance and reliability is still disappointing. Working on alternate designs.

Mechanism testing is going well at Ball and these subsystems are almost ready for integration.

The SOFA mechanism is delivered to Ball from Moog.

Instrument-level testing support hardware (RIAF/RCAF) being calibrated and readied for testing with the Stimulus in thermal-vac.

I&T reoptimization plan implemented.

Variable Cunductance Heat Pipes (VCHP) successfully complete thermal testing.

RSC is ahead of schedule with the new lot of IR FPAs. Two flight candidates are being evaluated at the DCL for possible use in IR Build 1.

I&T reoptimization plan implemented.

16th SOC meeting held at STScI.


I&T reoptimization plan created to allow subsystems to be shipped to GSFC as soon as possible. Subsystem testing will be done at GSFC, with minor exceptions.

Optical Stimulus functional demonstration completed at Orbital. The OS will be disassembled and shipped to the GSFC SSDIF cleanroom.

MEB heat pipes fit checked and shipped to Ball.

IR FPA vibration tests completed and reveal a need to limit vibration testing of the flight devices.

TECFIRE issues continue to be worked. Alternate designs being evaluated.

IR Filter Wheel interference problem identified and resolved.

All Marconi CCDs tested at the DCL for critical performance parameters so that the contract can be closed.

ICAL starts detailed planning and organization for the testing phase.


TECFIRE testing reveals some design and process issues which are being worked.

Mini-stimulus reshipped to Ball after repairs.

Channel Select Mechanism interference problem identified and resolved.

IR filter wheel complete except for one additional filter that was added by the SOC.

Calibration subsystem parts arrive at Ball.


The UVIS shutter has been installed in the OB.

UVIS filter wheels completed.

UVIS Surrogate detector assembly completed and is functioning.

Final set of two flight CCDs delivered to Ball.

First flight IR FPA delivered to Ball for Build 1.

Electronics manufacturing in full gear at J&T.


IR Detector Milestone Review/15th SOC Meeting held at Rockwell Scientific. The IR detectors received a "yellow" rating because of three areas of performance shortfall: short wavelength QE, read noise, and dark current instability. Plans proceed for making another lot.

The contract with Barr is complete. All UVIS filters complete and delivered to Ball.

Internal heat pipes delivered from Swales to GSFC.

Stimulus structure rework completed at Orbital. The stimulus primary mirror was successfully removed and stripped for recoating. Integration begins.

Mini-stimulus acceptance testing completed and shipped to Ball. Returned to GSFC to repair a loose lens.

A coolant leak during a UVIS shutter test delays the test. Contamination issues addressed.

Closeout meeting held at Marconi. All CCD production is complete.

Maurice Argoud retires.