The James Webb Space Telescope! Dean C. Hines (STScI) George Sonneborn (GSFC) John Stansberry (STScI) JWST Town Hall 45 th Meeting of the Division for Planetary Sciences October 10, 2013
JWST Imaging Modes! Mode Imaging Aperture Mask Interferometry Coronography Instrument Wavelength (microns) Pixel Scale (arcsec) Full-Array* Field of View NIRCam* 0.6 2.3 0.032 2.2 x 2.2 NIRCam* 2.4 5.0 0.065 2.2 x 2.2 NIRISS 0.9 5.0 0.065 2.2 x 2.2 MIRI* 5.0 28 0.11 1.23 x 1.88 NIRISS 3.8 4.8 0.065 ------ NIRCam 0.6 2.3 0.032 20 x 20 NIRCam 2.4 5.0 0.065 20 x 20 MIRI 10.65 0.11 24 x 24 MIRI 11.4 0.11 24 x 24 MIRI 15.5 0.11 24 x 24 MIRI 23 0.11 30 x 30 10/10/2013 JWST Town Hall DPS 45 DCH - 2
JWST Spectroscopy Modes! Mode Slitless Spectroscopy Instrument Wavelength (microns) Resolving Power (λ/δλ) Field of View NIRISS 1.0 2.5 150 2.2 x 2.2 NIRISS 0.6 2.5 700 single object NIRCam 2.4 5.0 2000 2.2 x 2.2 Multi-Object Spectroscopy NIRSpec 0.6 5.0 100, 1000, 2700 3.4 x 3.4 with 250k 0.2 x 0.5 microshutters Single Slit Spectroscopy Integral Field Spectroscopy NIRSpec 0.6 5.0 100, 1000, 2700 slit widths 0.4 x 3.8 0.2 x 3.3 1.6 x 1.6 MIRI 5.0 ~14.0 ~100 at 7.5 microns 0.6 x 5.5 slit NIRSpec 0.6 5.0 100, 1000, 2700 3.0 x 3.0 MIRI 5.0 7.7 3500 3.0 x 3.9 MIRI 7.7 11.9 2800 3.5 x 4.4 MIRI 11.9 18.3 2700 5.2 x 6.2 MIRI 18.3 28.8 2200 6.7 x 7.7 10/10/2013 JWST Town Hall DPS 45 DCH - 3
James Webb Space Telescope Project Status! JWST is making great progress and remains on schedule and budget for a 2018 launch." All four science instruments are now at GSFC."
Integrated Science Instrument Module (ISIM)!
Near-Infrared Imager & Slitless Spectrograph (NIRISS) Fine Guidance Sensor (FGS)!
Near-Infrared Camera (NIRCam)!
Near-Infrared Spectrograph (NIRSpec)!
Mid-Infrared Instrument (MIRI)!
James Webb Space Telescope Project Status! JWST is making great progress and remains on schedule and budget for a 2018 launch." All four science instruments are now at GSFC." New HgCdTe detector arrays are being built, correcting a major flaw in the pixel architecture. Fifteen new focal plane arrays will be installed in the three near-ir instruments before the 3rd cryo test." FGS/NIRISS and MIRI are mounted in the ISIM structure and are in the midst of the first of three cryo-vacuum tests of the instrument system. The two later cryo tests will have all four instruments."
MIRI, FGS & NIRISS Installed in ISIM!
James Webb Space Telescope Project Status! JWST is making great progress and remains on schedule and budget for a 2018 launch." All four science instruments are now at GSFC." New HgCdTe detector arrays are being built, correcting a major flaw in the pixel architecture. Fifteen new focal plane arrays will be installed in the three near-ir instruments before the 3rd cryo test." FGS/NIRISS and MIRI are mounted in the ISIM structure and are in the midst of the first of three cryo-vacuum tests of the instrument system. The two later cryo tests will have all four instruments." Fifteen of 18 primary mirror assemblies are complete with their flight actuators, delivered to GSFC, and ready for assembly on the optical structure."
Cryo-Vac Testing Flight Segments!
JWST Primary Mirrors! All mirror segments have been pollished and cryo-tested 15 completed mirrors have been delivered to Goddard 10/10/2013 JWST Town Hall DPS 45 DCH - 14
James Webb Space Telescope Project Status! JWST is making great progress and remains on schedule and budget for a 2018 launch." All four science instruments are now at GSFC." FGS/NIRISS and MIRI are mounted in the ISIM structure and are in the midst of the first of three cryo-vacuum tests of the instrument system. The two later cryo tests will have all four instruments." New HgCdTe detector arrays are being built, correcting a major flaw in the pixel architecture. Fifteen new focal plane arrays will be installed in the three near-ir instruments before the 3rd cryo test." Fifteen of 18 primary mirror assemblies are complete with their flight actuators, delivered to GSFC, and ready for assembly on the optical structure." The spacecraft critical design review, the final design step for the JWST observatory flight system, will take place in Dec 2013."
The Orbit & Deployment! 10/10/2013 JWST Town Hall DPS 45 DCH - 16
JWST Moving Target Tracking Status! JWST has the capability to observe moving targets with apparent rates up to 0.030 arcsec/second under fine guidance control" Includes Mars and beyond, but not all possible comets or near- Earth objects" May be possible to support slightly higher rates (0.060 arcsec/ sec?)" Non-linear Guide Star ephemeris uplinked, stored by observation scripts, and executed by Attitude Control Subsystem" Ephemeris defined by 5 th order Chebychev polynomial derived from JPL HORIZONS" The pointing performance in moving target control mode is expected to be excellent (<0.01, 1-σ), based on recent dynamicbody non-linear simulations." Moving target observations will be supported in first year of JWST observing." Cycle 1 Call for Proposals in 2017!
http://webbtelescope.org" http://www.stsci.edu/jwst/" http://www.stsci.edu/jwst/science/solar-system" http://jwstinput.wikidot.com/" 10/10/2013 JWST Town Hall DPS 45 DCH - 18
Blue font denotes milestones accomplished ahead of schedule, orange font denotes milestones accomplished late.
Milestone Performance Since the September 2011 replan JWST reports high- level milestones monthly to numerous stakeholders * Late milestones have been or are forecast to complete within the year. Shutdown related delayed milestones included in this tally
Planning for the Next UV-Opt-IR Space Telescope Julianne Dalcanton University of Washington
History 1995 Commissioned by AURA 1. Extend HST lifetime 2. Build JWST 3. Develop space interferometry 23+ year lead time between report & launch
Why This Exercise? 1995 2000 2018 2014 2020 2035
Why This Exercise? EXOPAG COPAG In the UVOIR, the goals and requirements are very similar One mission + Broad science = Large Community
Committee Chaired by Julianne Dalcanton & Sara Seager Broad mix of technologists and scientists AURA, NASA, & ESA observers Not exclusive. Drawing expertise broadly from community.
Committee Suzanne Aigraine Niel Brandt Charlie Conroy Julianne Dalcanton Lee Feinberg Suvi Gezari Olivier Guyon Walt Harris Chris Hirata John Mather Marc Postman Dave Redding David Schiminovich Sara Seager Phil Stahl Jason Tumlinson technologists scientists Observers: Heidi Hammel (AURA) Paul Hertz & Mike Garcia (NASA) Arvind Parmar (ESA)
Process Draw heavily from rich body of existing work (ATLAST, TPF-C, THEIA, EUVO) Outreach to community (one-on-one now, broader soon) Phone cons. Oh golly, the phone cons. Face-to-Face Meeting: Dec 2013, Spring 2014 Report: Summer 2014
Key Goals Compelling science theme that resonates universally (Congress, Public, etc) Compelling capabilities that engage the astrophysics community Feasible, fundable technology path
Emerging science themes Detecting & characterizing habitable exoplanets.
Exoplanets Drivers Large aperture - Issues: How large? Requires mature DRM. Launch vehicle? Superb mirror (10 s of picometer stability) - Issues: stable over what timescale & mode? Coronographic capability - Issues: Internal (hard requirements) vs external (inefficient, limited lifetime)
Emerging science themes Exoplanets The Universe in High-Definition HDST: High-Definition Space Telescope
Size scales 1 pc 5 pc ~200 pc HDST: Resolving 100 pc star forming regions everywhere in the universe! 1 pc resolved out to 10-25 Mpc. ALMA: molecular gas on ~0.1-0.5 scales JWST: Heavily enshrouded stars BJWST: Emerging stars
General Astrophysics Drivers Large aperture: Throughput + Resolution UV (102 nm) through NIR (2.5 µm, non-cryo) - Issues: Coatings, Compatibility w/ Coronography Large FOV + Spectroscopic Multiplexing - Issues: Tradeoff between cost of more complex instruments vs efficiency gains
Additional Considerations Serviceable as means of risk reduction, possible lifetime extension If an internal coronograph is used, explore providing capabilities to allow starshade at later time.
Technological issues Mirror technology Reducing vibration UV Coatings Coronography Low read noise detectors Launch vehicle (<9.2m w/ existing)
Moving forward Improve science requirements, particularly those in support of coronography (help from EXOPAG?). Identify aperture thresholds, based on DRMs. Create technology development plan for investment in advance of 2020. Present viable joint exoplanet-astrophysics space mission to 2020 decadal review.
Help from EXOPAG SAGs? Refine coronography requirements on telescope stability (timescales, modes, etc) Improve understanding of interaction between coatings & coronography Develop efficient strategies for minimizing time needed for exoplanet characterization (i.e., preselection of targets, reducing number of repeat visits to confirm planet, etc). Prioritization of wavelength ranges for bandlimited coronography.
Help from COPAG? May request help with technology assessment.
Input welcome! Please talk to any committee member, at any time. Suzanne Aigraine Niel Brandt Charlie Conroy Julianne Dalcanton Lee Feinberg Suvi Gezari Olivier Guyon Walt Harris Chris Hirata John Mather Marc Postman Dave Redding David Schiminovich Sara Seager Phil Stahl Jason Tumlinson