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Interferometer System Overview I I Interferometer System Overview - Gary Blackwood Interferometer Systems Manager October 14, 2003 A NASA Origins Mission TPF Interferometer Systems 23 July 2003 pg 1 Interferometer Sy sterns Will Deliver Structurally-Connected Interferometer concept for the minimum TPF science - FFI (d - .- Formation-F1y ng Interferometer concept for the full TPF science Technology results, end-to-end simulation, and model validation to demonstrate viability of How: concepts Architecture Team A NASA Origins DesignTeam Mission Technology Teams TPF Interferometer Systems 23 July 2003 pg 2 Interferometric Exo-Planet Detection Star is always on the dark fringe (null) Detected Planet crosses the fringes as the baseline rotates: optical energy signal modulation due to planet + + + + time or baseline rotation angle Dual Chopping Bracewell Nulling Architecture star planet zodi 0 A Chopping: a method for background suppression I antenna pattem on the sky Chopping enables fast modulation of signal time 'u Id) t) aJ F1 0F1 uI t) 3 Uk m 0E \;t: m Formation Flying Interferometer Strawman ~~~ 0 Dual-chopped Bracewell 0 Four Four apertures, 4.0 m diameter Collectors 0 +/- 45 degrees sky coverage 0 Array size: 70 to 150 m I\ 0 Delta-4 heavy, 22.4 m fairing 0 L2 Orbit 0 150 stars surveyed in 2 years FFI is sensitivity-limited Combiner TPF Interferometer Systems 23 July 2003 pg 7 Strawman Comparison . Structurally Connected j Formation Flying I- Interferometer Interferometer"., ,,,,, Science Ca pab ilitv ,i ,. I", 'Number of Stars i I- 56 150 Science io _I As - -" ----- XI I^ -x xx" I 14 Jy per -s( at 12 pm) -"14 *- E ng inee r i n g Ass um p t ion s SNR for Detection area 0.7-1.5 0.7-1.5 Array size (m) II "- I _I 70 to 150 i 36 Number of apedures ~ i 4 - 4 -" .2 "I egrees, from anti-sun x ^^I I_ 45 1- I I 5% 7% Collaboration with ESA TPF Book Design ESA - Darwin Objective - make common nulling architecture recommendation Figures of Merit: - Detection Sensitivity - Launch packaging - Fuelusage - Beam combiner complexity A NASA Origins - Leakage suppression - Array size Mission TPF Interferometer Systems 23 July 2003 pg 9 L I L TPF Interferometer Sv stems J 0 JPL I Industry participation University participation c] Gene Serabyn Cmiraa Mawgemen Chief Archiled Goddard Serge Dubovltrky III--.-------'I +L Beltrand Mennesscn ObseNslory Smlalim ken1 Ware Inlegraed Welmng Inslmerd Formslim Ccmfrol Testbed Mecharwcal Element$ GregM- Plan Rand Ddectim Testbed I Ben Man Wene 611Ahd Paul MacNeal - Stefan Mail" I opk4 Elementr Beam Con1rdEric Bloemhd Ted"0gs DumLo I Top Technical Concerns: Concems Prioritized by: - Gap (Seriousness) .)compare Reqt to SOA - Urgency + will it be a showstopper in 2006? - Trend + is anyone else working on it? Top Concerns Mitigated by: - System Engineering + Design Team c4 - Technology Development 9Technology Teams - Inheritance + Current, by 2006, by Phase C/D A NASA Origins Mission TPF Interferometer Systems 23 July 2003 pg 12 Interferometer Building Blocks: Categories for Concerns Performance star planet zodi 0 Requirements Structures I Metrology I I Formation Flying OR Large ion Structure I&T Technical Concerns (1 of 2) J~~ S I .- CORE COMMON z StarLight Nulling BeamTrain & Flight and Mission System U S Nulling Architecture Launch packaging of SCI and FFI ii+ a, Beam Combination C Interspacecraft communications -(d LL Internal Thermal Emissions - Sky coverage / thermal shield .-(d +L Spatial Filters v) packaging 2 Intensity Matching & I- Phase Control Integration and Performance Verification Instrument Controls L End-to-end flight system test Pointing control of compressed beam Overall system complexity Cry0 Delay Line path stability Detectors A NASA Retired Primarily by Technology Origins Cryocoolers Mission Retired Primarily by System Engineering I’ TPF Interferometer Systems 23 July 2003 pg 14 MTd 3a, m 2 ss E c, t: E rccE xa, 2 %a, 0 c,a, *r( c, Hc 2 e e xa, 0x 2 Eom rcc-sg u au c) 23 k;? oa, 0, 0E 41 e e e NOT on the Top Concerns List because Large IR optics NGST Relative linear metrology StarLight, SIM Absolute metrology Code R: Distributed Spacecraft SIM Technology program Detectors SIRTF, NGST Passive cooling NGST NGST Knowledge of on orbit disturbances and environment SIM, NGST, SIRTF, IPEX Microdynamic Disturbances A NASA Origins IPEX Mission SIRTF TPF Interferometer Systems 23 July 2003 pg 16 Achromatic Nulling Testbed Kevd Intended Result: 4~10~~WL Null, 20% bv\i - Stable white ight null with 50% IR White Light Null vs. OPD bandwidth 7-12 pm Laser Null, 10 pm Two Detector Nulling Polarizer and 50um Pinhole 10000000 1000000 100000 10000 1000 100 10 1 0 500 I000 1500 2000 2500 3000 3500 4000 4500 Sample No. T'PF Interferometer Systems 23 July 2003 pg 17 Planet Detection Testbed J~~ 4-beam demonstration of dual-chopped Bracewell 0 - Planet extraction ( planeustar contrast), at 10 um - null depth - null stability - Amplitude and phase control (0.4%, 4 nm) Functiona diagram of TPF nuller A NA! Origir Missil I rr inrerreromerer aysrems L3 July LUU5 Nulling and Planet Detection JlpL A NASA Origins Mission TPF Interferometer Systems 23 July 2003 pg 19 Core Interferometer Technology J~~ S 10.- v) Mid-Infrared Spatial Filters Cryogenic Delay Line Adaptive Nuller Deformable A NASA Origins Mission TPF Interferometer Systems 23 July 2003 pg 20 Cryogenic Structures Technology J~L St ruct urally-Con nected Interferometer Testbed A NASA Origins Mission TPF Interferometer Systems 23 July 2003 pg 21 Formation Flying Technology c 1 A- Formation Control Testbed 1 Formation Sensor Testbed MIT SPHERES A NASA Origins Mission TPF Interferometer Systems 23 July 2003 pg 22 Next Steps Architecture - Update concerns - Ensure testbed plan effectiveness - Nulling architecture recommendation with ESA - Science capability assessment ( Design Team - Next level of design - Engineering Capability assessment Technology - Deliver results per plan - Meet interim milestones A NASA Origins Mission TPF Interferometer Systems 23 July 2003 pg 23 Summarv Interferometer Systems Will Deliver Structurally-Connected Interferometer concept for the minimum TPF science Formation-Flying Interferometer concept for the full TPF science I- P Architecture Trades Concerns Identification / Mgmt b' 0 Design Team 0 A NASA Technology Development Origins Mission TPF Interferometer Systems 23 July 2003 pg 24 I - A NASA Origins Mission TPF Interferometer Systems 23 July 2003 pg 25 TOP Concerns: Core Interferometry JP L c .-0 v) Category Primary Concern TPF Requirement .-v) 2 z Starlight Nulling Nulling architecture Survey 30- 150 stars for terrestrial planets US Beamtrain ii c, Beam combination 4 or 6 beams, null 6.5- 17pm ca -(d [L - Internal thermal emissions .-a << 100 photons/sec c,L v) 9 ~~~ tj Spatial Filters 70% throughput in single mode, 6.5-17m I- c4 Intensity matching 0.2% Phase control 1nm (all frequencies) ~ & Instrument Pointing control accuracy of 50 mas b Controls compressed beam Cryogenic delay line closed loop 0.1 nm at 40K stability A NASA 0rig i n s Mission Detectors Cryocoolers 30mW at 6K TPF Interferometer Systems 23 July 2003 pg 26 Common Concerns Category Primary TPF Requirement Concern Flight & Mission Launch packaging of Self imposed System structure, formation flight systems Interspacecraft Continuous reliable high data communications rate 4 Mbitdsec Sky coverage At least +/- 45 deg ~~~ Integration and End to end flight system Ability to verify multi- Performance test collector distributed flight system Verification E Overall system Acceptable risk A NASA complexity Origins Mission I’ TPF Interferometer Systems 23 July 2003 pg 27 Top Concerns: Formation-Flying JPL Category Primary Concerns TPF Requirements Formation-F1 ying Long-term system robustness 5- 10 years System Performance of fine formation control 1 cm range, 20 arcsec bearing accuracy Algorithm functionality in deep space 5 s/c autonomous sensing collision avoidance performance Course acquisition sensor 50 cm, 1 deg, 4n; sterarian FOV with no calibration maneuvers c4 Formation Flying RF interference from thermal shield Low multipath effects on RF range Accommodation measurements Inter spacecraft stray light << 100 photons/sec A NASA Origins Mission TPF Interferometer Systems 23 July 2003 pg 28 Top Concerns: Connected Structure ApL Category Primary TPF Concern Requirement ~~ Precision Stability of long lnm, 36m, 40K Cryogenic Cryogenic structure Deployed Cry0 hinge and latch stability < 100m Structure Structural modeling tools Confident prediction of performance & b A NASA Origins Mission I’ TPF Interferometer Systems 23 July2003 pg29 .
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