Chart: 1 Adaptive Reconnaissance Golay-3 Optical Satellite (ARGOS) Prof David W. Miller Chart: 2 ARGOS Overview ISS Moon Frictionless Air Bearing RWA Surrogate Ground Station M.I.T. Angular Resolution at λ=550 nm: 0.35 arcsec Wavelength Regime: 400-700 nm FOR (Field-of-Regard): 120° (full cone) FOV (Field-of-View)-min: 3 x 3 arcmin SNR 100 (Min) Pointing Accuracy: +/- 10 arcsec Autonomous Operation: > 1 hour Angular Resolution at λ=550 nm: 0.35 arcsec Wavelength Regime: 400-700 nm FOR (Field-of-Regard): 120° (full cone) FOV (Field-of-View)-min: 3 x 3 arcmin SNR 100 (Min) Pointing Accuracy: +/- 10 arcsec Autonomous Operation: > 1 hour Wireless COMM Station First field operation in May Goal : Demonstrate the feasibility of Interferometry technology Goal : Demonstrate the feasibility of Interferometry technology Chart: 3 Full Structure Chart: 4 Sub-Aperture Manufacturing TAKAHASHI 8-inch High Precision (RMS WF errors 1/20 λ) Telescope Final Design Designed optimized achromatic doublet to convert a focal telescope to afocal with Magnification m=10 ?FK51/BaK2 –? CTE 5.3 –0.0027 RMS Error –Some sensitivity to thermal shock –-Manufacturable tolerances ?FK51/BaK2 –? CTE 5.3 –0.0027 RMS Error –Some sensitivity to thermal shock –-Manufacturable tolerances FK51 BaK2 Chart: 5 Relay Optics Design 1. Sub Aperture 2. Collimator 3. FSM+ODL 4. Pyramidal Mirror 5. Beam Combiner 6. CCD 1 2 3 4 5 6 The Advantages of Two Mirror Design the cost, the controller complexity, less reflectance loss, smaller possible misalignment errors, compactness The Advantages of Two Mirror Design the cost, the controller complexity, less reflectance loss, smaller possible misalignment errors, compactness Chart: 6 Allowable Structural Misalignments B= FSM rotation A B 45-B 45-A+B = 45- B 2B=A B= 0.5 *A *10 = 5 A. In reality, a factor of 6.4 works well up to 0.01 degree Telescope Tilt [Deg] [arcsec] FSM Comp [Deg] Max 0.034 degree FSM OPD [mm] Strehl Ratio Aberrated SR restored 0.0001 0.36 -0.00064 0 0.687 0.982 0.001 3.6 -0.0064 0 0.016 0.979 0.005 18 -0.032 0 0.192 0.907 0.01 36 -0.064 0 0.064 0.604 0.01 36 -0.064 0.0002 0.189 0.859 Magnification m=10 Chart: 7 Passive/Active Actuators 1 2 3 4 5 6 FSM+ODL ? Angular Range +/- 600 μrad ? Angular Res. +/- 0.05 μrad ? Linear Range 12 μm ? Linear Res. 0.2 nm FSM+ODL ? Angular Range +/- 600 μrad ? Angular Res. +/- 0.05 μrad ? Linear Range 12 μm ? Linear Res. 0.2 nm FSM MOUNT ?Angular Range +/- 7° ? Angular Res. +/- 0.0008° (14 μrad) ? Linear Range 1 cm ? Linear Res. 1 μm FSM MOUNT ?Angular Range +/- 7° ? Angular Res. +/- 0.0008° (14 μrad) ? Linear Range 1 cm ? Linear Res. 1 μm 7° 600 μrad 0.05 μrad FSM 14 μrad Mount Pyramid Errors w/o FSM Correction SR = 0.444 Pyramid Errors w/ FSM Correction SR = 0.960 Pyramidal Mirror Pyramidal mount Chart: 8 Attitude Control System (ACS) Sensor 2: Viewfinder Sensor 2: Viewfinder ACS Actuator: Reaction Wheel ACS Actuator: Reaction Wheel Body rate Body rotation Wheel speed + τ e Q dQ Sensor 3: Rate Gyro Sensor 3: Rate Gyro Sensor 1: Electronic Compass Sensor 1: Electronic Compass Active Balancing System Active Balancing System Chart: 9 Structures Design Chart: 10 Sparse-aperture Optics/Control System (SOCS) Framework PSF PSF X Analyze Optics Performance Requirements X Analyze Optics Performance Requirements Y Determine Array Configuration Y Determine Array Configuration Z Determine Tolerable Beam Combining Errors Z Determine Tolerable Beam Combining Errors [ Design/Build Sub-Aperture Telescope [ Design/Build Sub-Aperture Telescope \ Design Relay Optics \ Design Relay Optics _ Develop Wavefront Sensors,Controllers _ Develop Wavefront Sensors,Controllers ^ Design, Analyze, Build Structures ^ Design, Analyze, Build Structures Track WFE Budget θr θr EE EE SR SR ACS ACS SNR SNR FOV FOV MTF MTF L L D D # of Aperture # of Aperture Piston Piston Tilt/Tip Tilt/Tip Pupil mapping Pupil mapping # Reflection # Reflection Geometry Geometry # Control Channel # Control Channel Beam Combiner Beam Combiner A s s e m bly / A l ignment Errors A s s e m bly / A l ignment Errors RMS WF Error Budget Tree r Focal_1 Focal_1 M=d/D M=d/D FSM FSM FMs FMs ODLs ODLs Structure Vibration Structure Vibration ]Design CCD System ]Design CCD System Bea m Combini nng Errors Bea m Combini nng Errors Su b Aperture R M S W F E Su b Aperture R M S W F E Optical Co mpo n ents Errors Optical Co mpo n ents Errors Residual Optics Desig n W F E Residual Optics Desig n W F E Allowable misalignment Allowable misalignment Chart: 11 Determination of Array Configuration A (x,y) abs( )^2 S (x,y) Amplitude Spread Function Point Spread Function (PSF) P (ξ,ζ) Auto-correlation H (ξ,ζ) Complex Pupil Function Optical Transfer Function (OTF) Angular Resolution, Strehl Ratio Requirement Angular Resolution, Strehl Ratio Requirement Find suitable PSF, MTF Find suitable PSF, MTF Determine the corresponding L, D Determine the corresponding L, D Chart: 12 Impact of [L D] on Resolution Final Selection for the ARGOS testbed L=0.19185 m D=0.210 m (8 inch COTS telescope) Final Selection for the ARGOS testbed L=0.19185 m D=0.210 m (8 inch COTS telescope) Chart: 13 Phasing Error Analysis – Piston(OPD) Error I ∝ πD(1 + cos( r)) λ 2 J 1 (πD sin r / λ ) πD sin r / λ 2 e j2π ( L k r / λ ) cos( δ k ?θ ) e jφ k k =1 n ∑ 2 - Menneson’s Equation - simplified -4 -2 0 2 x 10 -6 0.5 1 -4 -2 0 2 x 10 -6 0.2 0.4 0.6 0.8 1 -4 -2 0 2 x 10 -6 0.2 0.4 0.6 0.8 1 -4 -2 0 2 x 10 -6 0.2 0.4 0.6 0.8 1 -4 -2 0 2 x 10 -6 0.2 0.4 0.6 0.8 1 1.2 -4 -2 0 2 x 10 -6 0.2 0.4 0.6 0.8 1 1.2 1.4 -4 -2 0 2 x 10 -6 0.2 0.4 0.6 0.8 1 1.2 -4 -2 0 2 x 10 -6 0.2 0.4 0.6 0.8 1 1.2 -4 -2 0 2 x 10 -6 0.2 0.4 0.6 0.8 1 1.2 -4 -2 0 2 x 10 -6 0.2 0.4 0.6 0.8 1 1.2 Golay w/o OPD Golay w/ OPD Monolithic I Array =3+2cos( 3cos(π/6+θ)2πLr/λ+φ 12 ) +2cos( 3cos(π/6?θ)2πLr/λ+φ 13 )+2cos( 3sin(θ)2πLr/λ+φ 23 ) +0.2λ -0.2λ λ/10 was suggested as maximum piston (OPD) error λ/10 was suggested as maximum piston (OPD) error Chart: 14 Phasing Error Requirement – Tilt / Pupil Mapping Error Pupil Mapping Error : Golden Rule of Beam Combining D/L (Entrance Pupil) =d/l (exit pupil) Max allowable = 12 μm Pupil Mapping Error : Golden Rule of Beam Combining D/L (Entrance Pupil) =d/l (exit pupil) Max allowable = 12 μm FEM Tilt Error Analysis predicts maximum allowable: 0.35 μrad=20 μ Deg FEM Tilt Error Analysis predicts maximum allowable: 0.35 μrad=20 μ Deg Chart: 15 Magnification vs Shear Error ? Sub-aperture magnification can be tuned to maximize allowable shear error (lateral pupil mapping error) thereby reducing control complexity. Chart: 16 ZEMAX, CODE-V ? Zemax is a professional ray tracing/optical design software ? Sequential, Nonsequential Ray Tracing ? Optimization of optics design ? PSF, MTF, Spot Diagram, Imaging Analysis ? Tolerancing and Sensitivity Analysis Chart: 17 Complete WF Error Budget Distortion 0.015 Field Curvature 0.020 Other abberations 0.013 Optical Design Errors (Residual Design Error) 0.028 Fabrication + alignment 0.015 Thermal 0.01 Collimator 0.0009 Subtelescope w/ Collimator 0.017 Fabrication 0.015 Thermal 0.01 Alignment 0.010 Primary 0.021 Fabrication 0.015 Thermal 0.01 Alignment 0.010 Secondary 0.017 Beam Combiner Manufacturing Error 0.027 Piston(Phase) Error 0.028 Tilt/Tip Error 0.016 Pupil Mapping Error 0.015 Magnification Error 0.015 Sensor Error 0.010 Actuator Error 0.01 Beam Combining Error 0.041 Inter-subtelescope alignment 0.015 Pointing/Focus 0.01 Assembly Deformation 0.01 FSM ODL FM @ BC Fold Mirrors Alignment 0.01 Assembly/Alignment 0.029 Thermal Deformation 0.02 Jitter/Drift (Image) 0.015 Jitter/Drift (Pupil) 0.015 Gravity Release Error 0.010 Environmental Error 0.0309 Total Wavefront Error 0.0727 (total RMS) < 0.075 Strehl Ratio = 2 (2 / ) e πσ λ? ,σ= RMS Wavefront error. Chart: 18 Optical Cost Models ? Investigate economical viability of modular optics given performance constraints ? Focus on monolithic Cassegrain telescopes versus Golay-3 design ? Use real data and experience from ARGOS δk Lk B Dk lk b dk sub-telescope plane (input p up il) combiner plane (exit pupil) foca l p la ne (image pupil) object k-th aperture beam combiner relay optics Chart: 19 Literature Search for Cost Models Kahan, Targrove, “Cost modeling of large spaceborne optical systems”, SPIE, Kona, 1998 Humphries, Reddish, Walshaw,”Cost scaling laws and their origin: design strategy for an optical array telescope”, IAU, 1984 Meinel, “Cost-scaling laws applicable to very large optical telescopes”, SPIE, 1979 Meinel’s law: 2.58 0.37 [M$] (1980)SD=? Chart: 20 Small Amateur Telescopes 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 0 0.5 1 1.5 2 2.5 3 x 10 4 Telescope Diameter D [m] Telesco pe Purch a se Cost C [20 0 1 $ ] Telescope Cost CER (Aperture): C=28917*D 2.76 ? Priced various amateur telescopes –DHQ f/5 – DHQ f/4.5 – D Truss f/5 – Obsession f/4.5 – Celestron G-f/10 ? Fit power law ? Exponent surprisingly similar to Meinel’s Law 2.76 28917CD= Chart: 21 Professional Telescope OTA cost 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 0 0.5 1 1.5 2 2.5 3 3.5 4 x 10 5 Aperture Diameter D [m] OTA Cost [2 001 $ ] Ritchey-Chretien Classical Cassegrain Company: Optical Guidance Systems (http:www.opticalguidancesystems.com) CERs for Ritchey-Chretien Classical Cassegrain Remarkable Result: virtually identical power law across completely different product lines. 2.80 376000 RC CD=? 2.75 322840 CC CD=? Chart: 22 ACS Mass and Cost ? Reaction wheel mass scales w/ momentum capacity ? Reaction wheels dominate ACS mass ? ACS cost is function of mass ? Scale using ARGOS ACS mass and cost ? Inertia depends on sub-aperture masses and geometry ? Assumed 1.5 deg/sec slew rate 0 10 20 30 40 50 60 70 0 2 4 6 8 10 12 14 Mass [Kg] Momentum Capacity [Nms] Ball, Honeywell, and Ithaco RWAs [Kg = 2.49 Nms 0.41 ]] Kg = 2.49Nms 0.41 0.8 $ ACS o ACS cKg= Chart: 23 Sub-System Cost Tables Chart: 24 Sub-System Cost Tables Chart: 25 Sub-System Cost Tables Chart: 26 Labor Cost Table Sub-System Yearly Rate Spring Summer Fall Spring Total Total Recurring Passive Optics Soon-Jo Chung $70,000 200 200 200 200 800 $61,833 $15,458 Janaki Wickrema $50,000 260 0 260 130 650 $35,885 $7,177 Erik Iglesias $50,000 260 360 260 130 1010 $55,760 $7,177 David Ngo $50,000 260 360 260 130 1010 $55,760 $7,177 Active Optics Soon-Jo Chung $70,000 150 160 150 150 610 $47,148 $11,594 Abran Alaniz $50,000 260 360 260 130 1010 $55,760 $7,177 Praxedis Flores III $50,000 260 0 260 130 650 $35,885 $7,177 ACS Carl Blaurock $70,000 0 0 78 78 156 $12,058 $6,029 Ayanna Samuels $50,000 260 0 260 130 650 $35,885 $7,177 Susan Kim $50,000 260 0 260 130 650 $35,885 $7,177 Paul Wooster $50,000 260 0 260 130 650 $35,885 $7,177 Structures Marc dos Santos $50,000 260 0 260 130 650 $35,885 $7,177 David LoBosco $50,000 260 0 260 130 650 $35,885 $7,177 PAS Raymond Sedwick $70,000 104 96 104 104 408 $31,535 $8,038 Soon-Jo Chung $70,000 0 0 0 104 104 $8,038 $8,038 Carolina Tortora $50,000 260 0 260 130 650 $35,885 $7,177 Christopher Rakowski $50,000 260 360 260 130 1010 $55,760 $7,177 Dustin Berkovitz $50,000 260 360 260 130 1010 $55,760 $7,177 SOC John Keesee $90,000 104 96 104 104 408 $40,545 $10,335 Eric Coulter $50,000 260 0 260 130 650 $35,885 $7,177 Daniel Kwon/Lisa Girerd $50,000 260 0 260 130 650 $35,885 $7,177 Management Paul Bauer $70,000 104 96 104 104 408 $31,535 $8,038 David Miller $90,000 104 48 104 104 360 $35,775 $10,335 Raymond Sedwick $70,000 26 0 26 26 78 $6,029 $2,010 John Keesee $90,000 26 0 26 26 78 $7,751 $2,584 Total $919,903 $190,115 ARGOSHours EB/OHD Wrap 2.12 Student $50,000 Staff $70,000 Management $90,000 Chart: 27 Labor Cost Table Sub-System mult Total Recurring mult Total Recurring mult Total Recurring Passive Optics 1 $209,240 $36,990 0.3 $62,772 $11,096.88 1 $209,240 $36,990 Active Optics 1 $138,794 $25,948 0.3 $41,638 $7,784.38 1 $138,794 $25,948 ACS 1 $119,714 $27,560 1 $119,714 $27,560.00 1 $119,714 $27,560 Structures 1 $71,771 $14,354 0.6 $43,063 $8,612.50 1 $71,771 $14,354 PAS 1 $186,980 $37,608 1 $186,980 $37,607.92 1 $186,980 $37,608 SOC 1 $112,316 $24,689 1 $112,316 $24,689.17 1 $112,316 $24,689 Management 1 $81,090 $22,967 1 $81,090 $22,966.67 1 $81,090 $22,967 Total $919,903 $190,115 $647,572 $140,318 $919,903 $190,115 Sub-System mult Total Recurring mult Total Recurring mult Total Recurring Passive Optics 1.5 $313,859 $55,484 2 $418,479 $73,979 2.5 $523,099 $92,474 Active Optics 2 $277,588 $51,896 3 $416,381 $77,844 4 $555,175 $103,792 ACS 1 $119,714 $27,560 1 $119,714 $27,560 1 $119,714 $27,560 Structures 2 $143,542 $28,708 3 $215,313 $43,063 4 $287,083 $57,417 PAS 1 $186,980 $37,608 1 $186,980 $37,608 1 $186,980 $37,608 SOC 1 $112,316 $24,689 1 $112,316 $24,689 1 $112,316 $24,689 Management 1 $81,090 $22,967 1 $81,090 $22,967 1 $81,090 $22,967 Total $1,235,088 $248,912 $1,550,272 $307,709 $1,865,456 $366,506 ARGOS Monolith Golay-3 Golay-6 Golay-9 Golay-12 Chart: 28 Golay System Costs ?Optimum Golayis D eff -dependent ? Labor moves Golay benefits to larger D eff ? Golay’s sacrifice Encircled Energy EE=83.5% EE=26.4% EE=9.3% EE=3.6% EE=2.2% Chart: 29 Compact Golay-3 ? Reduces side-lobes, improves EE, improves fill factor (SNR) ? Sacrifices cost savings ? Adding bus & relay optics costs defines Golay-3 vs. monolith breakpoint * ARGOS L=1.2xD L=D (Golay) L=0.8xD * ARGOS Chart: 30 Compact Hex Arrays EE=62% EE=50% EE=40% EE=31% EE=23% Deff=0.42m Deff=0.64m Deff=1.79m Compact Golay-3 Compact Golay-6 Compact Golay-9 Compact Golay-12 Compact Hex MonolithGol a y - 3 Gol a y - 6 Gol a y - 9 Gol a y - 1 2 ?Larger D eff favors higher order Golays ? Golay-3 & Hex compact better than higher order Golays ? Compactness limited by sub- aperture interference ? Hex is not as cost-efficient at providing full uv-coverage as Golay Equal D eff (angular resolution)