COS SMOV Morning Update
12 June 2009
This presentation contains material that is embargoed until after the SM4
ERO press conference. Images/spectra of external (astronomical) objects
may not be altered, distributed, reproduced, published, displayed, or used in
any other way without the consent of the STScI Director or the HST Project.
Agenda
• COS-to-FGS Alignment / Coarse Focus : 11468: Visit 1 of 2
(COS08)
• Upcoming COS SMOV Timeline
.
COS-to-FGS Alignment / Coarse Focus :
•
Visit 1 (of 2)
COS “First-Light”: 5x5 search pattern to locate target in PSA aperture at
each of 3 focus settings
– Target found in several tiles of pattern including initial blind pointing; highest
signal found in tile 23 [(xoffset , yoffset) ~+0.2, ~-2) arcsec]
– Analysis of the COS proposal 11468 alignment images indicates that the
V2/V3 aperture location should effectively be offset by (1.672, -1.363) arcsec;
a corresponding update of the COS aperture mechanism is therefore required
• An appropriate Ops Request will be generated and executed prior to execution of
prop 11469 visit 1, currently scheduled for ~09.164:14:13:00
– Pointing for next visit (1146901) will be adjusted with RE-USE TARGET
OFFSET using the (V2,V3) offset above
– NO OSM mechanism (focus) adjustment required at this time
•
“Get-ahead” test ACQ/SEARCH and ACQ/IMAGE exposures
– ACQ/SEARCH: global threshold failure; FSW uses model to estimate
comparison of detected signal with background
• Background set to relatively large pre-launch estimate; patchable constant to adjust;
will do so prior to next usage in 11469 visit 12 in approximately 2 weeks
– ACQ/IMAGE: FSW determined target offset magnitude properly, however
appears to have been applied with wrong sign in at least one coordinate (along
dispersion); investigation continuing
•
STScI POS-TARG x-coordinate movements applied with opposite sign,
under investigation
COS-to-FGS Alignment / Coarse Focus :
Visit 1 (of 2)
Embargoed figure - Do not distribute
Upcoming COS SMOV Timeline
• Day 163: Fri 12 June
– 11356 visit 9 of 13 (COS23) FUV HV Turn-on
• ramp from HVLOW to fourth intermdiate ramp value, dump DCE, wave ,
dark exp
• OPS request required: clear NSSC-1 COS event flag 3 set in 1135608
• 1135609 163:17:25:00 - 163:18:02:28
• No event flag set; leave SI at HV level for 4 hours; then execute 1135610
– Contingency OPS request in place to place FUV in INHIBIT if anomaly
• science data
– 11356 visit 10 of 13 (COS23) FUV HV Turn-on
• After 4-hour wait at fourth intermediate ramp value, dump DCE RAM,
return to HVLOW
• sets event flag 3
• 1135610 163:21:40:00 - 163:21:41:36
• clear NSSC-1 COS event flag 3 prior to visit 11
Upcoming COS SMOV Timeline
• Day 164: Sat 13 June
– 11468 visit 2 of 2 (COS08) COS-to-FGS Alignment / Coarse Focus
• s/c visit to facilitate real-time uplink of offset pointing information to be
used in as OFFSET 11469A in 1146901 (which follows within ~1 hour);
uplink nominal focus, aperture mechanism, and other mechanism position
updates based on analysis of 1146801;
• 1146802 164:12:54:25 - 164:13:17:58
– 11469 visit 1 of 12 (COS09) COS Fine Optical Alignment
• Use same astrometric target as 11468 visit 1
• Apply uplinked offset (from 1146802) to blind pointing position to
approximately center target in PSA; use same orient and same astrometric
guide stars (GS) as 1146801; no target acquisition
• Obtain MIRRORA images at each of 15 moderately-spaced focus
positions (from +525 to -525 in steps of 75 units)
• 1146901 164:14:00:24 - 164:15:02:44
• After analysis of imagery uplink refined nominal focus value, offset
pointing , and possible mechanism position updates via real-time contact
in 11469 visit 2 on Mon
Upcoming COS SMOV Timeline
• Day 165: Sun 12 June
– 11356 visit 11 of 13 (COS23) FUV HV Turn-on
•
•
•
•
ramp from HVLOW to final ramp value, dump DCE, wave , dark exp
OPS request required: clear NSSC-1 COS event flag 3 set in 1135608
1135611 165:19:00:00 - 165:19:38:28
No event flag set; leave SI at HV level for 8 hours; then execute 1135612
– Contingency OPS request in place to place FUV in INHIBIT if anomaly
• science data
• Day 165: Mon 13 June
– 11356 visit 12 of 13 (COS23) FUV HV Turn-on
• After ~8-hour wait at final ramp value, dump DCE RAM, return to
HVLOW
• sets event flag 3
• 1135612 166:03:20:00 - 166:03:43:24
• clear NSSC-1 COS event flag 3 prior to visit 13