SPACE TELESCOPE SCIENCE INSTITUTE Operated for NASA by AURA An Update on the COS Development Status TIPS 21 August 2003 (Last COS TIPS: Dec 2002) COS Integrated SI (Aft End)

Sembach 2 of 21 TIPS - 21 August 2003 COS Timeline Summary Instrument integration activities (Jan-Mar 2003) –Calibration platform installed, electronics, enclosure, etc –FUV02 (flight spare) detector qualifications completed FUV detector swap and alignment (March-April 2003) –FUV02 performance better at longer ; “flatter” throughput –Alignment checked under N 2 purge with CAOS/HOMS Environmental tests of integrated instrument (April 2003) –GSFC: EMI/EMC, acoustics, vibration, metrology Initial thermal balance, alignment, and testing in vacuum completed in July 2003 –To confirm focus/spectral resolution/throughput/operations

Sembach 3 of 21 TIPS - 21 August 2003 COS Timeline Summary (con’t) Instrument currently out of vacuum chamber at Ball –Working issues discovered during initial testing T-Vac activities to begin September 11 Science calibration to occur September 18 - October 12 Delivery to GSFC expected in late October 2003 Integrated pipeline testing in May 2004 SMGT planned for late July 2004 Working to launch date of May 2005

Sembach 4 of 21 TIPS - 21 August 2003 COS: pre-acoustic test; packing for return to Ball

Sembach 5 of 21 TIPS - 21 August 2003 COS Integrated SI and Enclosure

Sembach 6 of 21 TIPS - 21 August 2003 COS Issues of Interest Spectra in Bright Object Aperture (BOA) have coma –ND2 filter (2 mm cube) has 0.25 o wedge –Resolution degraded by factor of ~4 in NUV, less in FUV –No serious science impact Spectral lines sometimes found to be “tilted” under N 2 purge in CAOS/HOMS after FUV02 detector swap –Time variable, observed for FUV external lamp spectra –Most likely related to failing PtNe calibration lamp –Not seen after new lamp installed or in later vacuum tests

Sembach 7 of 21 TIPS - 21 August 2003 Removal of COS from Vacuum Chamber Internal ion pressure gauge not functioning –Problem traced to incorrect signals fed to electronics box; fixed RASCAL chief ray not aligned as it was prior to pump down –Chief ray remeasured; tip/tilt mirrors corrected Interpoint converter found to be faulty after check of calibration lamp voltage and current telemetry – LVPS board removed, x-rayed at GSFC –Solder leads lift from solder joints under vacuum –Other converters (5) x-rayed to ensure sufficient strain relief –Spares also being checked –Stiffener plates (Kovar) being bonded to tops to prevent stress

Sembach 8 of 21 TIPS - 21 August 2003 STScI Thermal Vacuum Activities Instrument scientists supported initial science verification activities in late June - early July in Boulder, CO –Hartig, Leitherer, Sembach participated on-site –Friedman analyzed spectral repeatability data –Approx. 500 datasets produced in two week period Science calibration data archived in MAST –All data run through OPUS and initial CALCOS processing –T-Vac retrieval screen available –Automated data transfer algorithms developed and implemented –Data also stored locally on COS machines for rapid analysis Keyword consistency checking –Fidelity of FITS keywords being checked with help from Rose/Hodge

Sembach 9 of 21 TIPS - 21 August 2003 COS Initial Testing Summary Instrument is performing as expected optically –Spectral resolution ~ 20,000 in medium resolution modes –Throughput meets/exceeds CEI specifications –Geometric distortion can be corrected accurately –Grating motion repeatability is as good as expected –Spatial resolution ~ 1 arc sec Final calibration activity plan being finalized by CU/Ball –Close cooperation with STScI Testing to resume in mid-September

Sembach 10 of 21 TIPS - 21 August 2003 Sample COS FUV Spectrum External PtNe calibration lamp (no distortion correction)

Sembach 11 of 21 TIPS - 21 August 2003 Sample COS NUV Spectrum External PtNe calibration lamp

Sembach 12 of 21 TIPS - 21 August 2003 Initial FUV Spectral Resolution Results - G130M External PtNe calibration lamp R = 

Sembach 13 of 21 TIPS - 21 August 2003 Initial FUV Spectral Resolution Results - G160M External PtNe calibration lamp R = 

Sembach 14 of 21 TIPS - 21 August 2003 Initial NUV Spectral Resolution Results G185M G225M G285M External PtNe calibration lamp R = 

Sembach 15 of 21 TIPS - 21 August 2003 GratingWavelength (Å)Efficiency Requirement G130M-B ±0.018>0.103 G130M-A ±0.017 G160M-B ±0.011>0.077 G160M-A ±0.016 G140L ±0.014>0.07 G185M ±0.0043>0.018 G225M ±0.0023>0.023 G285M ±0.0014>0.017 G230L ±0.029>0.021 TA ±0.0043No req TA1-Brt ±0.0003No req Initial COS Efficiency Estimates From Wilkinson et al. (2003, SPIE)

Sembach 16 of 21 TIPS - 21 August 2003 Initial Spatial Resolution Results TA1 Image (NUV) Double pinhole aperture 1” (~40 pixels) separation Dispersion (pixels) Cross Dispersion (pixels) Images are clearly resolved

Sembach 17 of 21 TIPS - 21 August 2003 Initial FUV Grating Motion Repeatability Results

Sembach 18 of 21 TIPS - 21 August 2003 Initial NUV Grating Motion Repeatability Results

Sembach 19 of 21 TIPS - 21 August 2003 STScI Ground System Development and COS Pipeline Bright object screening tool (ROBOT) in progress Flatfield commanding rework complete HST data volume study – COS on-orbit and pipeline estimates updated Bench testing of command certification SMS (T. Wheeler) Planning of Integrated Pipeline Test started COS Pipeline (CALCOS) COS Pipeline (CALCOS) – Most modules are now complete – Spectral merging procedures for FP-POS positions in progress – Testing to occur on integrated SI data from T-Vac

Sembach 20 of 21 TIPS - 21 August 2003 SMOV & SMGT Successful SMOV4 requirements review 30 July 2003 at GSFC Special commanding definition required by Oct 2003 –COS Operations Working Group will establish requirements SMOV activity summaries (Phase 1 proposals) definition Nov-Dec 2003 –Review presently scheduled for late Jan 2004 SMGT now planned for late July 2004

Sembach 21 of 21 TIPS - 21 August 2003 STScI User Support  STScI Instrument Division COS Staff – IS: Keyes, Sembach, Friedman; DA: McMaster – Leitherer transferred from COS to JWST in July 2003 (supporting T-Vac)  COS Handbooks – Mini-handbook for Cycle 13 being revised (August 2003) – Instrument handbook outline exists, work to continue after T-Vac  COS Exposure Time Calculators – Spectroscopic ETC software development in progress – Target acquisition ETC requirements delivered to APT group – Completion of ETCs expected in January 2004  COS Website

Sembach 22 of 21 TIPS - 21 August 2003 COS Performance (FUV)

Sembach 23 of 21 TIPS - 21 August 2003 COS Performance (NUV)

Sembach 24 of 21 TIPS - 21 August 2003 FUV02 / FUV01 QE Comparison