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TIPS Meeting 1.Observing Solar System Objects with JWST Ed Nelan 2.COS - Updates on COS DevelopmentKen Sembach 3.NICMOS StatusTommy Wiklind Next TIPS Meeting will be held on 16 January 2003. 19 December 2002, 10am, Auditorium
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Observing Moving Targets with JWST Ed Nelan TIPS Dec 19, 2002
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Observing Moving Targets with JWST Ed Nelan TIPS Dec 19, 2002 Ron Henry, Wayne Kinzel, Andy Lubenow, Knox Long, Vicki Balzano, Larry Petro, John Isaacs, Mark Abernathy, Rusty Whitman, Bill Workman
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Moving Targets Observations of moving targets with JWST is not part of the baseline plan. –Currently, there is no requirement for JWST to track a moving target The STScI proposal for the JWST Science & Operations Center (S&OC) does not include support for observations of moving targets. Science Working Group's interest in Solar System objects motivated a study by STScI to estimate the cost to the for supporting such observations.
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Moving Targets Cost estimates in this study are for the Ground System (S&OC), i.e., STScI, only. Cost for flight software development not included. –We did not investigate if JWST can track moving targets, or the cost in doing so (TRW) –We did not estimate the additional cost for FGS FSW (CSA) Can the Science Instruments observe the bright planets? –We did not address the cost for SI modifications (SI teams)
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Moving Targets Moving Targets are Solar System bodies: –Kuiper Belt Objects –planets –moons of planets –asteroids –comets Compared to stars, they are nearby, and they move –JWST parallax –ephemeris
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Moving Targets Outline of this presentation: Why observe moving targets with JWST ? What angular rates might be encountered? Costs: –Observatory efficiency, scheduling –Operations, proposal preparation, planning & scheduling ($) –Software development, I&T, maintenance ($$)
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Why Observe Moving Targets? Shoemaker-Levy 9
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Why Observe Moving Targets? Shoemaker-Levy 9 and Jupiter Impacts
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Why Observe Moving Targets? Between 1994 and 1996 ~35% of all HST public out reach releases involved Solar System observations. But only ~2% of the HST program was dedicated to Solar System observations.
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What’s involved in Moving Target Observations? Fixed targets (stars, galaxies, e.g.) are stationary with respect to the guide star. A Solar System object moves with respect to a guide star Proposal Preparation, Planning & Scheduling: –Ephemeris –JWST parallax –Tracking. Complicates selection of the guide star
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Fixed Target Observations Science Instrument FGS * * Fixed target
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Moving Target Observations Science Instrument FGS * * Moving target *
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At what angular speeds do Solar System bodies travel? From J. Nella,JWST kickoff Meeting, 10/23/02
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Angular rates of Neptune within JWST FOR 1 mas / sec
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Angular rates of Jupiter within JWST FOR 5 mas / sec
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Angular rates of Mars within JWST FOR 25 mas / sec
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Angular rates of selected objects within JWST FOR * Includes motion about Pluto-Charon barycenter
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Moving Target Observations may require long guide star track lengths Science Instrument FGS * * Moving target *
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Moving Target Observations may require short guide star track lengths Science Instrument FGS * * Moving target *
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Proposal Preparation, Planning and Scheduling The position of a Solar System object on the celestial sphere as seen from JWST will depend upon the the spacecraft’s position in its orbit about L2. –Orbit has a radius of 800,000km –Period of about 120 days. S/C’s predicted position will be uncertain by TBD% when forecast one year in advance (proposal preparation time). –Station keeping maneuvers difficult to predict. –Implications for S&OC’s generation of LRP. To investigate, we assumed 10% ephemeris uncertainty.
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JWST in L2 Orbit gs1 gs2
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JWST in L2 Orbit gs1 gs2
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JWST in L2 Orbit gs1 gs2
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JWST in L2 Orbit gs1 gs2
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JWST in L2 Orbit gs Not a problem with HST in low orbit, Earth’s ephemeris is well known.
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Proposal Preparation, Planning and Scheduling Uncertainty of a Solar System object’s position as seen by JWST due to a 10% error in spacecraft’s one year predicted ephemeris.
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Proposal Preparation, Planning and Scheduling If bad pixels in FGS cause loss of lock on guide star: –need an accurate ephemeris to verify the path of a guide star across the FGS while JWST tracks target is free of bad pixels. If the FGS can guide across bad pixels: –the uncertainty of the JWST predicted ephemeris is unlikely to present a major problem (proposals can be flight ready many months in advance) Uncertainty in long range forecast of spacecraft ephemeris might delay final selection of a guide star until a few months before observations occur. Impacts LRP.
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Observatory Efficiency, Event Driven Schedule Plan window Visit duration flexible constrained
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Visit with long plan window HDF
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Visit with short plan window 1.5 hours after SL-9 Impact
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JWST Event Driven Schedule Will observations of moving targets cause a loss of observatory efficiency? Observations will execute as visits within plan windows. Plan windows will overlap in time. Each plan window contains only 1 visit. Ideal Plan window is long compared to the visit duration. Visits execute at the earliest time possible. This approach minimizes gaps in observatory activities
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JWST Event Driven Schedule Overlapping Plan windows allow observations to execute according to events, and not be restricted to absolute times. Visit 1 Visit 4 Visit 2 Visit 3 time
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JWST Event Driven Schedule If visit 2 fails, visit 3 executes early. No idle gap, observatory efficiency preserved. Visit 1 Visit 4 Visit 2 Visit 3 time
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JWST Event Driven Schedule If visit 2 fails, visit 3 executes early. No idle gap, observatory efficiency preserved. Visit 1 Visit 4 Visit 2 Visit 3 time
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JWST Event Driven Schedule If visit 2 fails, visit 3 executes early. No idle gap, observatory efficiency preserved. Visit 1 Visit 2 fails Visit 3 executes early time Visit 4 executes early
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JWST Event Driven Schedule When time constrained observations populate the schedule, loss of observatory efficiency can result if failures occur Visit 1 Visit 4 Visit 2 Visit 3 time
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JWST Event Driven Schedule When time constrained observations populate the schedule, loss of observatory efficiency can result if failures occur Visit 1 Visit 4 Visit 2 Visit 3 time
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JWST Event Driven Schedule When time constrained observations populate the schedule, loss of observatory efficiency can result if failures occur Visit 1 Visit 4 Visit 2 Visit 3 time
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JWST Event Driven Schedule When time constrained observations populate the schedule, loss of observatory efficiency result when failures occur. Visit 1 Visit 4 Visit 2 Visit 3 time gap
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Distribution of target-local HST plan windows for Solar System targets, 2000-2002
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Visit with short plan window 1.5 hours after SL-9 Impact
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Visit with long plan window Saturn
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JWST Event Driven Schedule Observations of most Solar System objects can be scheduled when required tracking rates are very low. If guide star availability is the only constraint, visits can have long plan windows, and flexible scheduling. If target-local considerations determine plan window, restrictive scheduling results. –Visits cause loss of efficiency when visits upstream in the queue fail. Same as time constrained observations of fixed targets. Degradation of observatory efficiency due to Solar System observations not expected to be significant.
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JWST Event Driven Schedule Suppose all visits to all targets are of the same length and –JWST spends 3% of its time observing solar system targets, –And 20% of these observations are time constrained, –And only 10% of all observations upstream in the queue (including fixed targets) fail. Then the loss of observatory efficiency due to time constrained (Solar System and fixed target) observations is, assuming all visits are of the same length; 0.03 0.2 0.1 = 0.0006 = 0.06 %
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Proposal Preparation, Planning and Scheduling
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Cost to S&OC for Observing Solar System Bodies To facilitate costs analysis: –adopted an operations concept –identified requirements levied on the ground system and flight software to implement concept. –estimated $$ cost to meet the requirements. –estimated the cost for daily operations. The $$ cost to the S&OC is dominated by software development needed for the proposal preparation, planning, and scheduling systems.
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Observing moving targets with JWST Concept Assumptions All observatory level restrictions applied to fixed targets apply to moving target observations. Science instrument modes and target acquisition schemes used for fixed targets will suffice for moving target observations. JWST can track targets using an ephemeris. Only one guide star used for a visit. It shall be within the same FGS detector for the duration of the plan window.
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Observing moving targets with JWST Concept supports observations of any moving target. Flight software and hardware set the limits. Concept is similar to HST approach, but is consistent with event driven schedule architecture. Concept is not optimized for observations when the guide star availability time is less than the time required to gather the science data (fast comet). –Get science by scheduling multiple visits with short plan windows, each with new guide star. –Operations impact might be acceptable if instances are rare.
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Observing moving targets with JWST For economy we assumed maximum re-use of the HST moving targets ground system (APT, MOSS) – ~500,000 lines of code!!! Concept results in ~12% increase in the size of APT, the Planning & Scheduling System, and the Guide Star Selection System.
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Observing moving targets with JWST Summary from the S&OC perspective. Observing Solar System objects with JWST will be easier than with HST (L2 vs low Earth orbit). Time constrained observations of Solar System bodies are not likely to significantly reduce observatory efficiency (requirement is > 70%) Software for PP&S and GS selection system increases in size by ~12% over that needed for observing fixed targets.
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Observing moving targets with JWST Cost to S&OC for software development, maintenance, I&T and 2 years of operations is estimated to be $2.7M –5% increase in the baseline (fixed target) proposal. Afterwards, cost for yearly operations ~ $250K. –2% increase for daily operations. Total cost to the project can be determined when flight software & hardware impacts are considered. Will it happen? –????
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Why, or Why Not, Observe Moving Targets? Shoemaker-Levy 9
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TIPS Meeting 1.Observing Solar System Objects with JWST Ed Nelan 2.COS - Updates on COS DevelopmentKen Sembach 3.NICMOS StatusTommy Wiklind Next TIPS Meeting will be held on 16 January 2003. 19 December 2002, 10am, Auditorium
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SPACE TELESCOPE SCIENCE INSTITUTE Operated for NASA by AURA An Update on the COS Development Status TIPS 19 December 2002
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COS Optical Layout OSM1 positions 1 of 4 optics 2 degrees of freedom (rotation, focus) OSM2 positions 1 of 5 optics 1 degree of freedom (rotation) Calibration Platform 4 lamps, 3 beam splitters Aperture Mechanism positions 1 of 2 Apertures 2 degrees of freedom (x & y translation) FUV Detector Head (DVA) NCM2 (Collimating mirror) NCM3a, 3b, 3c (Focusing mirrors) Calibration Fold Mirror External Shutter (not shown) Cosmic Origins Spectrograph Hubble Space Telescope NUV Detector (MAMA)
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COS Instrument Timeline N 2 purge testing / alignment completed at Ball –test is not designed to confirm focus/spectral resolution Instrument being installed in enclosure Initial delivery to GSFC in late February 2003 –EMI and acoustic testing followed by mini-functional Thermal balance and science calibration in vacuum will occur in late April through early June 2003 Final instrument delivery to GSFC in June 2003
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COS under N 2 purge in cleanroom at BATC
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Sample G285M Science/Wavecal Wavecal – 3 bright stripes on left. Science – 3 weaker stripes on right. The sources of the glints have been identified and remedied. WavecalScience glint
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NUV G285M PtNe Wavecal Spectra - N 2 Purge Data Single grating tilt yields 3 stripes Resolution R ~ 20,000
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NUV G230L PtNe Wavecal Spectra - N 2 Purge Data Wavelength (Å) Three grating tilts required to cover the full range shown Resolution ~ 1.2 Å
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FUV G160M PtNe Wavecal Spectra - N 2 Purge Data
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COS Instrument Status (FUV) All optics installed and aligned FUV-01 flight detector currently installed FUV-02 spare detector undergoing final acceptance/qualification testing Team may propose a swap of spare and flight if spare has significant performance advantages over FUV-01; recommendation awaiting outcome of FUV-02 testing over the next 2-4 weeks
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COS Instrument Status (NUV) Flight detector (NUV MAMA) installed All optics installed and aligned – small alignment errors detected during N 2 purge testing have been corrected –Source of glint identified –Camera optic aligned –OSM1 flatfield tilt position verified
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COS Instrument Status: Current Issues FUV detector swap? FUV02 (currently designated as spare) may provide higher quantum efficiency, but needs consideration of other qualities (flat field, background, etc.): decision TBD –FUV02 vacuum leak fix corrected with elliptical O-ring –Door mechanism operated >40 times –Still needs final vibe and thermal vacuum tests
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COS Performance (FUV)
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COS Performance (NUV)
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FUV01 and FUV02 Quantum Efficiencies FUV01 FUV02
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FUV02 / FUV01 QE Comparison
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COS Instrument Status: Current Issues Manufacturing flaw caused the D 2 lamps to fail under vibration –Source of problem identified –New lamps manufactured (two not suitable) –Vibe and TVac tests ongoing (look good) Two lamps passed random vibe and sine burst tests Being installed in flight housings
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Calibration Platform Random Vibration Test
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STScI Ground System Development Phase 1 (1/1/00 – 6/30/00) vMacro Development vReconfigurations Phase 2 (7/1/00 – 12/31/00) vNUV Timetag Mode + Darks vFUV Timetag Mode + Darks Phase 3 (1/1/01 – 6/30/01) vFUV & NUV Accumulation Science Exposures vFUV & NUV Target Acquisition Exposures vFUV & NUV Target Peakup Exposures Phase 4 (7/1/01 – 12/31/01) vAperture Alignment Exposures vOSM1 Focus Alignment Exposures vOSM1 Rotation Alignment Exposures vOSM2 Rotation Alignment Exposures vFUV & NUV FP Split Exposures Phase 5 (1/1/02 – 6/30/02) vFUV & NUV GO Wavelength Calibration Exposures vFUV & NUV Flat Field Lamp Calibration Exposures vFUV & NUV Automatic Wavelength Calibration Exposures vSAA Contours Phase 6 (7/1/02 – 12/31/02) vSMGT Preparations vSMOV Special Commanding vFUV & NUV Anomalous Recovery vFUV & NUV Initial Turn-on vFUV & NUV BOP Target Screening Phase 7 (1/1/03 – 6/30/03) vFUV & NUV Lifetime Adjustments vCoordinated Parallels
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Phase 5 development completed – All science / calibration exposure development is now complete – A few miscellaneous commanding activities remain Phase 6/7 development in progress – Bright object protection target screening in progress – Initial preparations for SMOV and thermal vacuum tests begun – Schedule being reworked in light of launch slip STScI Ground System Development
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STScI Thermal Vacuum Preparations Instrument Scientists and Data Analysts will support TVac activities at BATC –Assisting with science calibration plan –Perform science calibration activities in May 2003 –Interested in helping? Contact Keyes/Sembach Data gathering –All COS thermal balance / science calibration data will be permanently archived at MAST –Data transfer document in preparation
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COS Pipeline and Data Activities COS Pipeline (CALCOS) –Most modules are now complete –Spectral merging procedures for FP-POS positions in progress –Full testing to occur on integrated SI data –Draft of ICD-47 (P. Hodge) is being reviewed COS Header Keywords –Standard header keyword selections/definitions for science and ACQ exposures completed –Established COS association requirements –Keyword “dictionary” in progress
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STScI User Support COS Instrument Handbook –Development to begin in Spring 2003 COS exposure time calculators –Spectroscopic ETC and target acquisition ETC are in preparation –Now due January 2004 STScI Instrument Division COS Staff –Keyes, Sembach, Leitherer, Friedman, McMaster COS website –http://www.stsci.edu/instruments/coshttp://www.stsci.edu/instruments/cos –to be “zoped” early next year
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TIPS Meeting 1.Observing Solar System Objects with JWST Ed Nelan 2.COS - Updates on COS DevelopmentKen Sembach 3.NICMOS StatusTommy Wiklind Next TIPS Meeting will be held on 16 January 2003. 19 December 2002, 10am, Auditorium
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NICMOS Status December 2002 1.Overview 2.Dewar Temperature Adjustment 3.HST Calibration Work Shop 4.Science (Mike Corbin)
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NICMOS Status December 2002 NICMOS is operational and is functioning according to expectations (better instrument than in Cycle 7)
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NICMOS Status December 2002 Updates & News NICMOS SMOV programs essentially completed ( coronagraphy performance moved to Cycle 11 calibrations) GO science programs started June 2002 Regular calibration programs are running New Instrument Handbook ready NICMOS is operational and is functioning according to expectations (better instrument than in Cycle 7)
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NICMOS Status December 2002 Special calibration & test programs Adjustment of the Pupil Alignment Mechanism no movement since Cycles 7 & 7N Linearity measurements done but not yet ready for CDBS High S/N flat fields done New ‘grot’ and bad pixel masks done
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NICMOS Status December 2002 Calibration Plans Temperature monitoring continuously Multiaccum darks monthly Focus stability monthly/bi-monthly Photometric stability monthly Dark Generator Tool Sosey executed/DRIP Intra-pixel sensistivity Mobasher executed/DRIP High S/N capability Gilliland executed/DRIP Polarimetry calibration Hines first epoch/waiting 2 nd Grisms calibration Thompson completed One time programs Monitoring programs DRIP = Data Reduction In Progress
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NICMOS Status December 2002 NIC1 NIC2 NIC3 Focus monitoring during Cycle 7, 7N and post-NCS
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NICMOS Status December 2002 On-going studies post-SAA Cosmic Ray Persistence Removal Absolute DQE measurement Zero-point verification/photometric calibration
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NICMOS Status December 2002 Dewar Temperature The NICMOS detectors are sensitive to temperature variations Temperatures are measured at the Neon inlet and outlet (72.4 K) NIC1 mounting cup temperature set point is 77.1 +/- 0.1 K but has been slowly increasing during the last ~4 months
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NICMOS Status December 2002
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NICMOS Status December 2002 Dewar Temperature The temperature increase is most likely due to parasitics because of the approaching warm season. A decision to increase the NCS’s compressor speed to lower the temperature 0.05 K has been taken by the NICMOS Group and forwarded to GSFC. A further change in compressor speed when the cooler season starts (April/May) is foreseen. The compressor speed change is relatively small (~10 rps).
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NICMOS Status December 2002 HST Calibration Work Shop NICMOS contributions NICMOS Status D. Calzetti The NICMOS Revival: Detector Performance in the NCS Era T. Böker Photometric Calibration of NICMOS M. Dickinson NICMOS Grism Performance in the Post Ice Age Era R. I. Thompson Coronagraphy with NICMOS G. Schneider Polarimetry with the NCS-enabled NICMOS D. Hines NICMOS Cycle 10 and Cycle 11 Calibration Plans S. Arribas NICMOS+NCS Era Darks L. Bergeron The NICMOS Cooling System: Technology in the Service of Science T. Böker Removal of post-SAA persistence in NICMOS data M. Dickinson Post-NCS NICMOS Focus and Coma Analysis E. Roye Combining NICMOS Parallel Observations A. Schultz Pushing NICMOS Cycle 7 Calibrations M. Silverstone NICMOS User Tools an Calibration Software Updates M. Sosey TALKSPOSTERS
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NICMOS Status December 2002 SUMMARY NICMOS is fully functional and operates according to expectations Calibration programs are up and running NCS compressor speed needs to be adjusted in order to keep the detectors at a constant temperature
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TIPS Meeting 1.Observing Solar System Objects with JWST Ed Nelan 2.COS - Updates on COS DevelopmentKen Sembach 3.NICMOS StatusTommy Wiklind Next TIPS Meeting will be held on 16 January 2003. 19 December 2002, 10am, Auditorium
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