TIPS COS Overview - Keyes : 18 May 2000 COS Overview v CDR: April 2000 v FUV delivery: January 2001 v Environmental (Thermal-Vac): spring 2002 v Launch: July 2003 – SM4 – replace COSTAR

TIPS COS Overview - Keyes : 18 May 2000 COS Design v Moderate Resolution (R~20,000) point-source spectroscopy; 0.1 arcsec pointing; 15 km/sec absolute (5 km/sec relative) radial velocity accuracy v Highest Possible Throughput v Maximize wavelength coverage per exposure v FUV: – single reflection system – large format solar-blind detector v NUV: – FUV concept not available (no large format detectors) – scanning system, enhance wavelength coverage through use of three camera optics

TIPS COS Overview - Keyes : 18 May 2000 COS Optics v Apertures – Primary Science Aperture (PSA): 2.5 arcsec circular field stop – Bright Object Aperture (BOA): 2.5 arcsec + ND2 (100x attenuation) circular field stop – Wavelength Calibration Aperture (WCA) – Flat Field Aperture (FFA) v Optical Elements (Gratings, Mirrors) – FUV: G130M, G160M, G140L – NUV: G185M, G225M, G265M, G230L, TA1 mirror

TIPS COS Overview - Keyes : 18 May 2000 COS FUV Optical Path v from Green, SPIE, March 2000

TIPS COS Overview - Keyes : 18 May 2000 COS NUV Optical Path v from Green, SPIE, March 2000

TIPS COS Overview - Keyes : 18 May 2000 COS Modes

TIPS COS Overview - Keyes : 18 May 2000 COS Detectors v FUV – Double Delay Line (DDL) detector > windowless, CsI photocathode, MCPs feed DDL anode > two 85 mm (dispersion-direction) x 10 mm segments (~10 mm gap between segments) > 2 x 16,384 x 1024 pixels; ~7 pixels per resolution element along dispersion > “stim pulses” to characterize stretching and shifting in both coordinates (unlike FUSE)

TIPS COS Overview - Keyes : 18 May 2000 COS Detectors v NUV – MAMA (STIS flight spare) > sealed CsTe photocathode > 25 mm x 25 mm detector format (constrains optical design) > 1024 x 1024 pixels; no subarrays; 2 pixels per resolution element > opto-isolator problem fixed

TIPS COS Overview - Keyes : 18 May 2000 COS Operating Characteristics v TIME-TAG will be prime mode – improve noise reduction – reduce data volume v Both channels can not be operated simultaneously PDF

TIPS COS Overview - Keyes : 18 May 2000 STScI Scheduling System v COS Operations Working Group (COWG) – Purpose: ongoing group to provide science-related input into Flight Software and HST “front-end” ground system development – Members: CU, GSFC, Ball, UCB, and STScI – Products: Instrument Operation Requirements (OP-01), Proposal Instructions – Schedule Highlights: 1 July commence TIME-TAG development

TIPS COS Overview - Keyes : 18 May 2000 COS Ground System Phased Development (Rev 2) v Phase 1 (2/15/00 - 7/1/00) – – Macro Development – – Reconfigurations > > FUV Single Segment Exposures v Phase 2 (7/1/00 - 1/1/01) – – FUV/ NUV Time-Tag Science Exposures > > Data buffer management > > FUV bright object protection > > Primary science aperture > > Bright object aperture > > Fixed subarrays based on aperture – – FUV/ NUV GO Wavelength Cal. Exposures – – FUV/ NUV Flat Field Lamp Cal. Exp. – – FUV/ NUV Dark Calibration Exposures

TIPS COS Overview - Keyes : 18 May 2000 COS Ground System Phased Development (Rev 2) v Phase 3 (1/1/01 - 7/1/01) – – FUV/ NUV Target Acquisition Exp. > > Data buffer management > > Fixed subarrays based on aperture – – FUV/ NUV ACQ Dispersion Peakup > > Data buffer management > > Fixed subarrays based on aperture – – FUV/ NUV ACQ Cross-Dispersion Pkup > > Data buffer management > > Fixed subarrays based on aperture – – FUV / NUV Accumulation Science Exp. > > Data buffer management > > Doppler correction > > No subarrays v Phase 4 (7/1/01 – 1/1/02) – – Aperture Alignment Exposures – – OSM1 Focus Alignment Exposures – – OSM1 Rotation Alignment Exposures – – OSM2 Rotation Alignment Exposures – – FUV / NUV Automatic Wavelength Calibration Exposures – – FUV / NUV FP Split Exposures

TIPS COS Overview - Keyes : 18 May 2000 COS Ground System Phased Development (Rev 2) v Phase 5 (1/1/02 - 7/1/02) – – FUV / NUV Initial Turn-on – – FUV / NUV Anomalous Recovery – – FUV / NUV Flux Distribution – – FUV / NUV BOP Target Screening

TIPS COS Overview - Keyes : 18 May 2000 COS Pipeline Systems v Special Goal – Be capable of processing uncalibrated observations, cataloging, and archiving data by Thermal Vac. v COS Calibration Working Group – Purpose: forum for direct discussion of COS calibration issues – Members: CU, Ball, UCB, FUSE (JHU), GSFC, and STScI – Products: calibration pipeline requirements, science header keywords, science data formats, reference file requirements – Schedule Highlights: calcos requirements by 1 Oct 2000

TIPS COS Overview - Keyes : 18 May 2000 COS v End