The Integrated Science Instrument Module Ground Test

The Integrated Science Instrument ModuleGround Test

Matt GreenhouseISIM Project ScientistNASA Goddard Space Flight Center23 July 2010

ISIM is the science instrument payload of the JWST

23 July 2010

The ISIM system consists of:– Four science instruments– Nine instrument support systems:

- Optical metering structure system- Electrical Harness System- Harness Radiator System- ISIM electronics compartment (IEC)- ISIM Remote Services Unit (IRSU)- Cryogenic Thermal Control System- ISIM Command and Data Handling System

(ICDH)- Flight Software System- Operations Scripts System

ISIM is one of three elements that together make up the JWST space vehicle

– Approximately 1.4 metric tons, ~20% of JWST by mass or cost

2Presentation to STScI Calibration Workshop: Approved for public release; distribution

unlimited.

The ISIM system completed CDR during March 2009 All science instrument ETU test programs have been completed

– All instrument ETUs have been delivered Flight model integration is underway on all instruments and supporting systems

NIRSpec Development Model NIRCam Engineering Test Unit

FGS Engineering Model MIRI Verification Model

23 July 2010 3Presentation to STScI Calibration Workshop: Approved for public release; distribution

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Making sure it all works ….

Science instruments and each of their 9 supporting systems are individually flight qualified prior to delivery to ISIM I&T

Ground testing at the ISIM element level is designed to (no order):– Verify instrument alignment with the ISIM structure– Verify instrument compatibility with the: harness system, ICDH, IRSU, FSW, & OSS– Verify design performance wrt EMI/EMC– Verify instrument compatibility with the FGS– Verify SI-to-SI compatibility for parallel mode dark calibration– Characterize thermal performance for model validation– Characterize ISIM performance stability for model validation– Correlate instrument performance in ISIM to instrument-level test results– Verify workmanship for flight environment– Measure mass properties

Approximately 200 requirements to be verified at ISIM assembly level ISIM is subsequently delivered to observatory-level I&T as a flight qualified

element


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ISIM is one of three element-level test programs

GSFC SSDIF

NG M8, M4 TVNG M8

NG M8

NG M8

GSFC SSDIF

ISIM I&T

Spacecraft Panel I&T

OTEI&T

Sunshield I&T

OTE Structure I&T

GSFC SSDIF, JSC 32

OTE/ISIM I&T

Cryo Optics Test

Spacecraft Element I&T

Facility

N/A

I&T ResponsibilityExecution

NASANGSTITTESA / Arianespace

CSG S5C, S5B, BAF, ZL3NG M8, LATF, M4 Vibe

Complete Observatory I&T

Launch Site I&T

LV Integ

Launch

NG M8

NG R8

Sunshield Pathfinders (EPF/IVA)

Observatory EM Test Bed (EMTB)

NG M8

OTE PathfinderStructure

JSC 32GSFC SSDIF

Pathfinder Optics Integration

Pathfinder Cryo Optics Test

NG M3

Propulsion Module I&T


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6Use or disclosure of data contained on this page is subject to the restriction(s) on the title page of this document.

The ISIM element test article (sans ICHD)

7Use or disclosure of data contained on this page is subject to the restriction(s) on the title page of this document.

ISIM Test Verification Flow

Receive Flight ISIM Electronics Compartment Structure with Backbone Harness

FLT IEC Integration(FLT E-box)

Receive Flight ISIM Structure

System Functional Test

Integrate: HAS,CHA, HR, Harness, SIs

IEC Sine & Random Vibe Test

IEC Mass Properties

DeintegrateFor Vib andMass Props ISIM Mass

Properties

Cryo Thermal Vacuum Test w/TMS and OSIM

EMI/EMCTest

Acoustics Test(ISIM & IEC)

Sine Vibe Test(ISIM Only)

Cryo Thermal Vacuum Test w/TMS and OSIM

Alignment Metrology

INS-20xxx

INS-20xxx

TST-20600 TST-20700

TST-20900 TST-21000

TST-21000

TST-20400 TST-20800 TST-21100 TST-20900

TST-21200

Clean, Inspect,Pack & Ship

TST-21300INS-21301

OTE Cryo VacAt JSC

TST-30000OTE Integration& Test Program

dI rI

dI

rI

rI – Re-Integrate ISIM and IECdI – De-Integrate ISIM and IEC

ISIM Gravity Release Test

TST-20910

ISIM will be tested at ~35 K in the GSFC SES chamber using a cryogenic telescope simulator (OSIM)

SES chamber(27 x 40 ft)

LN2 Shroud

LHe shroud

ISIM

OSIM

Vibration Isolation Supports

OSIM Primary MirrorAlignment Diagnostic Module

Fold Mirror 3 Tip/TiltGimbal Assembly

LHe shroud installation and test completed July 09

23 July 2010 8Presentation to STScI Calibration Workshop: Approved for public release; distribution unlimited.

Major ground support equipment required for ISIM I&T

Primary ground support equipment:– Cryogenic Optical Telescope Simulator (OSIM)

- Simulates Optical Telescope Element (OTE) with high fidelity– OSIM Beam Analyzer– Space environment simulator LHe shroud

- Enables ISIM testing at operating temperature– Cryogenic photogrammetry system

- Enables metrology of ISIM structure at operating temperature– ISIM Test Platform (ITP)

- Simulates OTE mechanical interface at cryogenic operating temperature ISIM simulators provided to support SI-Level testing:

– Ambient science instrument mechanical interface fixture (ASMIF)- Simulates ISIM structure mechanical interface for each instrument with high fidelity

– Science instrument test sets (SITS)- Simulates ICDH for each instrument


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The ISIM structure has passed key verification tests for cryogenic dimensional reputability and distortion

Carbon-fiber/cyanate-ester composite material– Primary launch-load bearing structure (warm launch)– High precision optical requirements

Key dimensional requirements for thermal cycling (300 to 30 K) verified to > 25 micron precision– Repeatability: 80 microns– Distortion: 500 microns

Key tests to-go:– Cryogenic and ambient strength proof tests– Modal survey


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Key Thermal Performance Test Objectives

• Best-controlled opportunity for ISIM thermal testing– 460 mW total power allocation to cryogenic portion of ISIM– Very sensitive to workmanship

• Thermal test objectives:– Thermal model correlation and validation– Workmanship/performance of critical thermal elements (heat straps,

harnesses, MLI, contamination control heaters/algorithms, trim heaters, temp sensors

– SI stability during multi-instrument operation– Sensitivity of ISIM to backplane interface temperature– MIRI thermal performance, heat load measurement within heat shield– IEC thermal balance, thermal cycling, transient stability, steady state

surface and electronics box temperatures


ISIM enclosure and passive cryogenic radiators replaced by precision controlled cryo-pannels

Flight high purity aluminum heat strap assemblies


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Flight radiators integrated at OTIS assembly level Q meters used to verify thermal loads and flight heat strap performance MIRI cooling provided by GSE cryo-cooler compressor

IEC and Harness Radiator Flight Configuration


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The ISIM electronics compartment successfully addresses one of most difficult engineering challenges of the JWST

The IEC accommodates 11 warm electronics boxes that must reside on the cryogenic side of the sunshield close to the science instruments

Rejects ~220 W of power to space in a controlled beam pattern to achieve required observatory thermal balance and avoid thermal stray light– Radiator beam pattern verified in prototype test

Key test to-go: full thermal balance

Flight Shell Flight Baffle


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IEC & HR test shrouds simulate flight cryogenic environment with high fidelity

IEC~ 25 K Test Shroud

HR with flight harnesses

HR (~ 20 - 25 K) Shroudlined with black honeycomb

23 July 2010 15Presentation to STScI Calibration Workshop:

Approved for public release; distribution unlimited.

Flight cryogenic radiators are replaced by a surrogate thermal management system

IEC Two Shroud Assembly LN2 shroud surrounded by dedicated He shroud plumbed to the primary chamber He shroud.

Harness Radiator with –V1 Shroud

Surrogate Thermal Management System (STMS) • Comprised of actively

controlled panels to produce environment of flight TMS to ISIM (Region 1)

LN2 ShroudGHe Shroud

Vibration Isolation System

Optical Telescope Element Simulator (OSIM)


Approximately 150 optical requirements are verified or cross checked during ISIM element testing

• Only opportunity for testing integrated instrument suite with flight-like beam of flight-like image quality/wavefront

• Comprehensive optical performance test plan confirms alignment, image quality, wavefront sensing capability

OPRG1• Basic optical capabilities

OPRG2• Wavefront and focus requirements• Calibration requirements for the MIMF

wavefront sensing algorithm

OPRG3• Pupil shear and rotation requirements

OPRG4• Fields of view, vignetting, stray light• Absolute pointing of ISIM

OPRG5• Co-boresight stability vs temperture

OPRG6• Performance of NIRCam wavefront

sensing and control components


Science Instrument (SI) sensitivity verification

SI-level requirements cover every filter and mode of the instrument

– Verified at instrument level as part of their qualification ahead of delivery to ISIM I&T- Component-level testing combined with models

Sensitivity models held under configuration control Spec values used for OTE parameters

Sensitivity benchmarks will be measured on SI internal sources during ISIM-element testing for correlation with SI-level test results

– POM contamination monitored with witness plates and NIRSpec spectroscopy on OSIM continuum sources


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JWST-RQMT-835: ISIM-153JWST Sensitivity: SN=10 in < 10,000s

Instrument

l (mm)

l/DlContinuum

Flux Density(nJy)

UnresolvedLine Flux

(10-21Wm-2)

NIRCam 2 4 11

FGS-TF 3.5 100 126

NIRSpec 3 100 132

NIRSpec 2 1000 0.52*

MIRI 10 5 700

MIRI 21 4.2 8700

MIRI 9.2 2400 10

MIRI 22.5 1200 560

* SN = 10 in < 100,000 s

Each of two cryogenic test cycles require ~20 weekswith ~ 6 weeks used for cool-down and warm-up


Learn more at: www.jwst.nasa.gov

Watch the ISIM being built at: www.jwst.nasa.gov/webcam.html

Read about JWST science mission objectives at: http://www.jwst.nasa.gov/science.html

Collaborate on JWST science investigations:http://www.stsci.edu/institute/conference/jwst2011


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ISIM Instrument characteristics wallet card

Instrument Channel/Mode Wavelength (microns)

Typical Spectral Resolution (l/Dl) FOV

Angular Resolution (arc sec)

Number of Sensor Chip

Arrays

Mega Pixels Detector Type / Format NIR=18 um pixels MIR=25 um pixels

Detector Temp (K)

Shortwave 0.6 - 2.3 4,10,100 2.2' x 2.2' each of 2 modules 0.032 / pixel 8 34 HgCdTe / 2048 x 2048 40Longwave 2.4 - 5.0 4,10,100 2.2' x 2.2' each of 2 modules 0.065 / pixel 2 8 HgCdTe / 2048 x 2048 40

1.0 - 5.0 1000

0.6 - 5.0 100see FOV

IFU 0.7 - 5.0 2700 3 x 3 arc-sec 0.10 slice widthImager 5 - 27 4-6 1.9' x 1.4' 0.11 / pixel 1 1 Si:As / 1024 x 1024 7Low Res Slit 5 - 11 100 5" x 0.6" see FOV 1 1 Si:As / 1024 x 1024 7

4.87 - 7.76 3000 3.7" x 3.7" 0.18 slice widthMed Res IFU 7.45 - 11.87 3000 4.7" x 4.5" 0.28 slice width 1 1 Si:As / 1024 x 1024 7

11.47 - 18.24 3000 6.2" x 6.1" 0.39 slice width17.54 - 28.82 2250 7.1" x 7.7" 0.65 slice width

FGS-TF 1.6 - 2.5, 3.2 - 4.9 100 2.2' x 2.2' 0.065 / pixel 1 4 HgCdTe / 2048 x 2048 40FGS-Guider 0.8 - 5.0 0.7 2.3' x 2.3' each of 2 modules 0.068 / pixel 2 8 HgCdTe / 2048 x 2048 40

Total ISIM 66

Wavelength (microns)

Instrument/Mode Bandwidth (l/Dl)

SNR Maximum Wall Clock Time (s)

2 NIRCam 4 10 10,000 11.40 0.11 NA3.5 FGS-TF 100 10 10,000 126.00 1.26 NA3 NIRSpec/Low Res 100 10 10,000 132.00 1.32 NA2 NIRSpec/ Med Res NA 10 100,000 NA NA 0.57

10 MIRI/ Broadband 5 10 10,000 700.00 7.00 NA21 MIRI/Broadband 4.2 10 10,000 8700.00 87.00 NA9.2 MIRI/Spectrometer 2400 10 10,000 NA NA 1022.5 MIRI/Spectrtometer 1200 10 10,000 NA NA 56.00

Instrument Mass: Region 1/2 Volume Observation Power Uncompressed Data Volume Flight Item PDR CDR Flt Delivery

(kg) R1 (m3) Region 2 (W) (Gbits / day) NIRCam Oct-04 May-06 Mar-10NIRCam 161 / 46 ~0.3 52 334 NIRSpec Dec-05 Oct-08 Nov-09NIRSpec 220 / 44 ~3.5 40 232 MIRI OBA Mar-05 Dec-06 Feb-10MIRI 102 / 33 ~2.5 37 96 MIRI Cryo-Cooler Feb-08 Dec-08 Jan-11FGS 92 / 21 ~0.6 51 68 FGS-Guider May-05 Mar-07 Mau 10Total SI 575 / 144 180 FGS-TF May-05 Mar-08 May-10

Total ISIM 1065 / 340 200 ISIM Oct-06 Nov-08 Sep-11SI/ISIM 0.54 / 0.42 0.90 NA

ISIM Fast Facts

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Schedule (ISIM Rev-F)

8 HgCdTe / 2048 x 20482

Unresolved Line Flux

(10-21 W m-2)

Long Slits (5) 1.0 - 5.0 100, 1000, 2700200 x 3500 mas x 3, 400 x 4000 mas, 100 x 2000 mas

K ey Instrument Charac teristics (as of Mar 06)

NIRCam

NIRSpec

203 x 463 mas clear shutter aperture, 267 x 528 mas pitch, 4 x 171 x 365 shutter array format, 9.7 sq arcmin mulit-object targetable solid angle

Multi-Object Spec

Greenhouse: Update: March 08

J WST Sensitivity (JWST-RQMT-000634 Rev-M Baseline)

Resource Allocations (as of May 07)

MIRI

Continuum Flux Density

(nJy)

Continuum Flux Density

(10-33 W m -2 Hz-1)

max ISIM = 458 (NIRCam prime, NIRSpec parallel cal 24% utilization


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NIRCam will provide the deepest near-infrared images ever and will identify primeval galaxy targets for the NIRSpec

Developed by the University of Arizona with Lockheed Martin ATC– Operating wavelength: 0.6 – 5.0 microns – Spectral resolution: 4, 10, 100– Field of view: 2.2 x 4.4 arc minutes– Angular resolution (1 pixel): 32 mas < 2.3 microns, 65 mas > 2.4 microns– Detector type: HgCdTe, 2048 x 2048 pixel format, 10 detectors, 40 K passive cooling– Refractive optics, Beryllium structure

Supports OTE wavefront sensing

Coronagraph Elements

Dichroic Beamsplitter

Collimator Triplet Subassembly

First Fold Mirror Subassembly

Shortwave Filter Wheel Assembly Elements

Shortwave Triplet Subassembly

Shortwave Fold Mirror

Pupil Imaging Lens

Shortwave Focal Plane Housing Fold Mirror

Longwave Focal Plane Housing Fold Mirror

Longwave Triplet Subassembly

Longwave Filter Wheel Assembly Elements

Pick-off Mirror Subassembly


The NIRSpec will aquire spectra of up to 100 galaxies in a single exposure

Developed by the European Space Technology Center (ESTEC) with Astrium GmbH and Goddard Space Flight Ctr

– Operating wavelength: 0.6 – 5.0 microns– Spectral resolution: 100, 1000, 3000– Field of view: 3.4 x 3.4 arc minutes

- Aperture control: programmable micro-shutters, 250,000 pixels

- Angular resolution: shutter open area 203 x 463 mas, pitch 267 x 528 mas

– Detector type: HgCdTe, 2048 x 2048 pixel format, 2 detectors, 37 K passive cooling

– Reflective optics, SiC structure and optics

MIcro-shutterArray

(f/12.5) Collimator

Prism/GratingWheel

CameraDetector

Array(f/5.67)

Telescope Focus (f/20)

Foreoptics

FilterWheel

Pick-off Mirror(s)

3.6’

3.4’

Detector Array

Fixed Slits and

IFU Aperture


Aperture control: 250, 000 programmable micro-shuttersSystem at TRL-8 and delivered to ESA June 2010

Human Hair 90 um Dia.

203 x 463 mas shutter pixel clear aperture, 267 x 528 mas pitch, 4 x 171 x 365 array


The MIRI instrument will detect key discriminators that distinguish the earliest state of galaxy evolution from more evolved objects

Developed by a European Consortium and JPL– Operating wavelength: 5 - 29 microns– Spectral resolution: 5, 100, 2000– Field of view: 1.9 x 1.4 arc minutes broad-band imagery

- R100 spectroscopy 5 x 0.2 arc sec slit- R2000 spectroscopy 3.5 x 3.5 and 7 x 7 arc sec integral field units

– Detector type: Si:As, 1024 x 1024 pixel format, 3 detectors, 7 K cryo-cooler– Reflective optics, Aluminum structure and optics

Optical Assembly Structural/Thermal Model


Developed by the Canadian Space Agency with ComDev– Operating wavelength: 0.8 – 4.8 microns– Spectral resolution: Broad-band guider and R=100 science imagery– Field of view: 2.3 x 2.3 arc minutes

- R=100 imagery with Fabry-Perot tunable filter and coronagraph– Angular resolution (1 pixel): 68 mas– Detector type: HgCdTe, 2048 x 2048 pixel format, 3 detectors – Reflective optics, Aluminum structure and optics

The FGS provides imagery for telescope pointing control & imaging spectroscopy to reveal primeval galaxies and extra-solar planets


The Integrated Science Instrument Module Ground Test

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isim element level

isim test verification

instrument alignment

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