The James Webb Space Telescope
Jonathan P. Gardner NASA’s Goddard Space Flight Center http://jwst.nasa.gov
Space Science Reviews, 2006, 123/4, 485 1
James Webb Space Telescope Integrated Science Instrument Module (ISIM)
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6.6m Telescope Successor to Hubble & Spitzer. Demonstrator of deployed optics. 4 instruments: 0.6 to 28.5 μm Passively cooled to < 50 K.
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Named for 2nd NASA Administrator
Secondary Mirror
Spacecraft Bus
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Primary Mirror
5 Layer Sunshield
Complementary to GMT, ALMA, WFIRST, etc NASA + ESA + CSA: 14 countries Lead: Goddard Space Flight Center Prime: Northrop Grumman Operations: STScI Senior Project Scientist: Nobel Laureate John Mather 2
Long Fairing 17m
Upper stage
Ariane V launch Kourou, French Guiana
H155 Core stage
Video
P230 Solid Propellant booster Stowed Configuration
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Video
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Wavefront Sensing and Control OTE Deployment / First Light (Image Mosaic)
SM Focus Sweep Segment Identification
NIRCam First Light
After Segment-Image Array
Commissioning
Segment Search
After Global Alignment
Segment-Image Array DHS (20 edges)
Global Alignment After Image Stacking
Image Stacking
After Coarse Phasing
Coarse Phasing (DHS) Single Field Fine Phasing Pupil Imaging
After SF Fine Phasing
Multi-Field Fine Phasing Wavefront Monitoring & Maintenance
JWST
Fine Phasing on JWST Testbed Telescope Clearly (repeatedly) Demonstrates Coherent Image Addition
116 nm rms
• Double Pass Phase Retrieval Estimate - ~0.95 Strehl ratio - (single pass at 1550 nm on TBT - Flight requirement is >0.8 Strehl @ 2micron •
Stacked Point Spread Function (left) contains random small tip/tilt and piston errors (Before)
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Phased PSF clearly indicates coherent addition and success of closed loop fine phasing (After)
• 1/6 scale test-bed Telescope
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Near-Infrared Camera
Lockheed Martin industrial partner
University of Arizona PI: Marcia Rieke Teledyne HgCdTe detectors
• Simultaneous observing at two wavelengths over 2.3’ x 4.6’ FOV.
Long Wavelength Detectors
Short Wavelength Detectors
Pick-off Mirror
• 7 Broad-band filters over 0.6 < λ < 5.0 m • Additional medium and narrow-band filters
Dichroic
• Filter wheels include wavefront sensing hardware. Filter Wheels
• Coronagraphy NIRCam 8
Near-Infrared Camera
Go Girl Scouts
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Near-Infrared Spectrograph
ESA instrument EADS Astrium prime contractor
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Multi-Object Spectroscopy
GSFC providing microshutters and detectors
– Micro-shutter array – 3.4’ x 3.4’ FOV.
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IFU, 3’’ x 3’’ R=1000 & R=3000
Video
– 3 gratings cover 1.0 < λ < 5.0 μm
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R=100 Prism – 0.6 < λ < 5.0 μm
Flight NIRSpec Micro-Shutters: 730 x 342 array of 203 x 463 mas pixels Flight Microshutters Integrated into Instrument 10
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European consortium George Rieke, US Science Lead Gillian Wright, EC Science Lead
Mid-Infrared Instrument
JPL providing detectors, cooling, management
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Broad-band Imaging
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5 < λ < 27 μm 1.4’ x 1.9’ FOV
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R=3000 IFU
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5 < λ < 28.5 μm 3” x 3” FOV
ETU First Light •
R = 100 Slit –
Flight MIRI at GSFC
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5 < λ < 10 μm
Coronagraphy Cryocooler to 7K
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MIRI Installation into ISIM
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Flight Fine Guidance Sensor Near-Infrared Imager and Slitless Spectrograph
Com Dev industrial partner
CSA contribution
Broad-band guider (0.6 – 5 microns) Science imagery:
Flight FGS
– Slitless spectroscopic imagery (grism) ‐ R ~ 150, 0.8 – 2.25 microns optimized for Ly alpha galaxy surveys ‐ R ~ 500, 0.7 – 2.5 microns optimized for exoplanet transit spectroscopy
– Sparse aperture interferometric imaging (7 aperture NRM) 3.8, 4.3, and 4.8 microns
Field of view: 2.3 x 2.3 arc minutes Angular resolution (1 pixel): 68 mas Detector type: HgCdTe, 2048 x 2048 pixel format, 3 detectors 14
FGS Delivery
JWST.ISIM.AUG.MSR
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Video
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Operations
• STScI has been designated as Science Operations Center
JWST at L2
Astronomer
Ka
S
• GO, Treasury and GTO programs similar to HST
STScI
TAC
DSN 17
JWST’s Flight Mirror Status
JWST
Flight mirrors arriving at GSFC
JWST
All mirrors are gold-coated
Gold Coatings Exceed Requirements Measured PM Run Reflectance (Visible / Near IR spectrometer 6 degree AOI) 99.5 99 98.5 Reflectance (%)
98 97.5 97 96.5 96 95.5 95 94.5 94 800
1000
1200
1400
1600
1800
2000
2200
2400
Wavelength (nm) A1
A2
A3
A4
A5
A6
B2
B3
B5
B6
B7
B8
C1
C2
C3
C4
C5
C6
C7
PM Average
Reqt
JWST Mirror Fabrication Raw Be billet (two mirrors)
JWST Mirrors made of beryllium Lightweight and stable at 40 K Brush-Wellman Primary segment Secondary
Tertiary
Machined & lightweighted by Axsys 92% material is removed
Mirrors polished at Tinsley Segment cryo-figure: 20 nm
Ambient Surface Figure JWST
Cryo Surface Figure
Flight Mirror Status • All flight primary mirrors completed w/gold coating Acceptance
testing completed
Video
Flight Mirror A4 in acceptance vibe • Mirror segments are now being
Mirror Segments Complete: - Cryogenic optical test (post-vibe) meets WFE requirement.
built up with actuators on the back for installation onto backplane. • Flight mirror fabrication program completed in 2011 JWST/Clampin/Observatory Status
JWST
Video
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JWST Secondary Mirror
Flight Secondary Delivered to GSFC JWST
Tertiary Mirror coated with gold!
JWST
Aft-Optics System
Predicted Image Quality: 2 μm & 4 μm
JWST
Predicted Image Quality: 0.7 μm & 1 μm
JWST
ISIM Flight Structure Completed
Structure in SES after Cryoset Test Complete
JWST_ISIM.June.MPR/34
OSIM/ISIM: The Show has Begun
Webbcam
Live update every 60 seconds http://www.jwst.nasa.gov/webcam.html.
Webbcam
Live update every 60 seconds http://www.jwst.nasa.gov/webcam.html.
Pathfinder Center Section Bonding Complete
JWST
Wings complete
JWST
1/3rd Scale Sunshield
JWST
Sunshield Status Status as of: 03/31/12
PROJECT: JWST
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Nexolve/NGAS making good progress on template work
Template Layer 5 “cup down” under 3X loading JWST.ISIM.APR.MSR
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Sunshield Deployment Testing
Observatory level cryo-vacuum testing will occur at the Johnson Space Center in Houston
JSC Chamber A
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Want to Learn More about JWST?
2007 Conference Proceedings Available on Amazon Gardner et al. 2006, Space Science Reviews, 123/4, 485 http://jwst.nasa.gov/scientists.html
White Papers: JWST in Decadal Survey Solar System Objects Dark Energy Transiting Planets Coronagraphy Planetary Systems Stellar Pops Star Formation Galaxy Assembly First Light Astrobiology Scientific Capabilities Observation Planning
Science White Papers http://www.stsci.edu/jwst/science/ 46
Workshop on “Frontier Science Opportunities with JWST” • • • • • •
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June 6-8, 2011 STScI Baltimore, Maryland, USA www.stsci.edu Webcast and charts: https://webcast.stsci.edu/webcas t/searchresults.xhtml?searchtype =20&eventid=147&sortmode=1 See white paper for summary: http://www.stsci.edu/jwst/science
jwst.nasa.gov
Latest News Project Milestones updated monthly
Social Media www.stsci.edu/jwst
Astronomy Software Tools ETC, PSF, APT
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The James Webb Space Telescope
Jonathan P. Gardner NASA’s Goddard Space Flight Center http://jwst.nasa.gov
Space Science Reviews, 2006, 123/4, 485 49
