Page 1 JWST Project Status AAAC, October 12, 2005 John C. Mather JWST Senior Project Scientist NASA GSFC

Page 2 Topics Science summary Mission summary Technology status Test plan status Contamination and Stray Light plan

Top JWST Goal - Find the First Light after the Big Bang How and from what were galaxies assembled? What is the history of star birth, heavy element production, and the enrichment of the intergalactic material? How were giant black holes created and what is their role in the universe ? Three instruments to do this: NIRCam (NASA/CSA), NIRSpec (ESA), MIRI (ESA/consortium/NASA), plus FGS-TF (CSA)     as seen by COBE Galaxies, stars, planets, life Galaxy assembly ? ?

SWG Meeting, STScI, September JW 4 The Epoch of Reionization Redshift Wavelength Lyman Forest Absorption Black Gunn-Peterson trough Patchy Absorption z<z i z~z i z>z i. Neutral IGM

National Aeronautics and Space Administration Goddard Space Flight Center 5 JWST Science The Eagle Nebula as seen by HST The Eagle Nebula as seen in the infrared Birth of stars and protoplanetary systems Planetary systems and the origins of life Galaxies in the UDF End of the dark ages: first light and reionization The assembly of galaxies

National Aeronautics and Space Administration Goddard Space Flight Center 6  -   sec      mJy R=2000, 1-  100 sec Spectra obtained with the JWST MIRI on the nearest systems can provide detailed insights to the minerals in ring particles and the nature of giant planets Simulated Vega Observation

National Aeronautics and Space Administration Goddard Space Flight Center Model Picture

Page 8 JWST Observatory Architecture Secondary Mirror (SM) Deployable tripod for stiffness 6 DOF to assure telescope alignment Optical Telescope Element (OTE) Stable over total field-of-regard Beryllium (Be) optics with GFRP/Boron structure Performance verified on the ground Primary Mirror (PM) 18 (1.315 m) hex segments Simple semi-rigid WFS&C for phasing 6 degree of freedom rigid body Radius corrections Deployable chord fold for thermal uniformity Tower Isolates telescope from spacecraft dynamic noise ISIM NIRCam, NIRSpec, MIRI & FGS Enclosure for FPE Simple Kinematic interface Sunshield Passive cool ISIM/OTE to ~40K Limits momentum buildup Spacecraft Bus Isolates reaction wheel noise

Page 9 JWST Orbit about the Sun-Earth L2 and Launch Configuration

National Aeronautics and Space Administration Goddard Space Flight Center 10 Ball AMSD II Be Mirror in Optical Test

Page 11 Primary Mirror Segment Actuations Lightweighted Beryllium Mirror Substrate Actuator for radius of curvature adjustment Actuators for 6 degrees of freedom rigid body motion, independent of ROC control Actuator development unit Observatory optical quality (mid and high spatial frequency) is manufactured into segments

A NIRCam Imaging Module A dichroic allows simultaneous observing at two wavelengths. This module’s dual filter wheels include pupils for wavefront sensing.

National Aeronautics and Space Administration Goddard Space Flight Center 13 Detector Technology Development NICMOS 256x256 HgCdTe WFC3 1024x1024 JWST Proto-type 4Kx4K NICMOS and IRAC arrays have demonstrated the basic detector architecture but with lower performance and smaller formats. TRL 4 achieved Feb 2002 with JWST performance levels achieved TRL 5 achieved Feb 2003 with JWST size 2Kx2K devices, mosaicing Astronomical Image with prototype, Sept Flight detectors being manufactured

National Aeronautics and Space Administration Goddard Space Flight Center 14 NIRSpec: ESA & Astrium > 100 Objects Simultaneously 9 square arcminute FOV Implementation: –3.5’ Large FOV Imaging Spectrograph –4 x 175 x 384 element Micro-Shutter Array –2 x 2k x 2k Detector Array –Fixed slits and IFU for backup, contrast –SiC optical bench & optics

Page 15 NIRSpec Schematic Fore opticsCollimator Camera Micro-Shutter Array Grating/Prism Wheel Detector Array Filter Wheel Pick-off Optics

Page 16 SAT Recommendations and Response

Page 17 Technology Status All technologies to be ready for by Non-Advocate Review (NAR) Key technologies: –Mirrors - flight mirror blanks made and being machined; EDU being polished; operator error (due to an unexpected feature in the machine) at Axsys drilled hole in one blank, no effect on schedule –Detectors - TRL 5 achieved in 2003, all performance specifications met; some HgCdTe detectors disintegrated, apparently due to insufficient cleaning prior to bonding to BCS (Balanced Composite Substrate); new recipe verified by repeated thermal cycles –Microshutters - GSFC - recipe found for keeping shutters flat at room temperature and cold; on track with all needed tests –ASICs - all performance specifications met; final foundry run starting with revised masks –Cryocooler - will select contractor in January

Page 18 Baseline “Cup Down” Tower Configuration at JSC (Before) Most recent Tower Design shows an Inner Optical Tower supported by a Outer structure with Vibration Isolation at the midplane. Everything shown is in the 20K region (helium connections, etc. not shown) except clean room and lift fixture. Plan called for 33KW He cooldown capability, 12 KW steady state, major challenges for JSC JSC currently has 7 KW He capability Plan required 10 trucks of LN2/day during cooldown Large Risk on Cooldown Time Assumptions Clean room Interferometers, Sources, Null Lens and Alignment Equipment Are in Upper and Lower Pressure Tight Enclosure Inside of Shrouds where Cryo Cycle Needed to Fix Problems

Page 19 Telescope Cup Up Gravity offloaded and On Ambient Isolators Connected to Concrete) Auto-Collimating Flats (isolators above connected to hard points on top of chamber). Center of Curvature Null and Interferometer Accessible from top Focal Plane Interferometer and sources accessible from below JSC “Cup Up” Test Configuration Isolators moved outside of shroud/vacuum Telescope comes in deployed on tracks with minimal time in chamber before pump down

Page 20 Contamination Plan “Cup Up” test at JSC is not a major contaminant source Launch effects are major driver –Ariane meeting planned for this fall –Particle generation by sunshield rubbing during launch? We will be able to clean mirrors Need independent review of all models, assumptions, methods Detail required: cleaned mirrors have different particle size distributions and different BRDF shapes than before cleaning Goal is twofold: –Cost-effective particulate contamination plan –Consistency with SAT assumptions regarding sensitivity losses

Page 21 Summary All review committees endorse JWST plans Scientific descope recommended by SAT accepted and being implemented Cost control and risk reduction approach endorsed by SAT and IPAO reviews Replan in progress for new launch date and budget Technology progress excellent, will be ready for NAR