TPF-C Technology Plan - Exoplanet Exploration Program - NASA

More documents

Recommendations

Info

Chapter 7 7.3 Error Budgets 7.3.1 Dynamic and Static Error Budgets Scope Current work is focused on adding new modeling capabilities and validating those capabilities in testbeds. Required models not presently in hand include: models of coating non-uniformities across large optics, stray-light and scattered light models validated at 1 × 10 -11 fractional scattered energy, and wave-front sensing and control models that demonstrate the ability to identify speckles at the 1 × 10 -11 level. Presently, there are no models of coating non-uniformities related to large-scale anisotropies in the deposition process. These effects might limit the useful optical bandwidth. Stray light models treat forward-scattered light as being uniformly shifted in phase relative to the nonscattered beam. This approximation must be validated or superseded by new models. Stray-light (multiply-reflected from baffles, edges, etc.) is calculated using standard stray-light software, but the accuracy of the calculations at the 1 × 10 -11 level has never been validated. Model validation for these new models and for existing ones (see below) is of the utmost importance. The HCIT is used to verify/validate the models that are used to predict requirements. These include diffraction, stray-light, scattered-light, polarization, mask performance, and pointing. In contradistinction, the planned subsystem testbeds, namely the sunshield, primary-mirror stability, secondary tower, and pointing-control testbeds, are used to verify that dynamic requirements can be met. Unlike HCIT they do not verify models that are used to predict the fundamental engineering requirements. The schedule for the dynamic and static error budgets is given in Table 7-1. State of the Art TRL N/A Static error budget terms are based on near-field propagation models, mask non-uniformity models, polarization ray-trace, and bidirectional reflectance distribution function based particulate-scattering models. The near-field propagation is calculated over the full bandwidth (500-800 nm) and includes the power spectral density (PSD) profiles for surface phase and amplitude. Mask design models evaluate complex transmission errors arising from design limitation and manufacturing errors, leading to derived requirements on substrate transmission PSD, lithographic/e-beam accuracy, and material dispersion. Ideal coronagraph mask performance is based on Fourier-plane (image/pupil conjugate) computations that have a noise floor better than contrast = 1 × 10 -13 . Polarization ray-traces are used to determine crosspolarization level, the effectiveness of coating designs, and tolerances on those designs. Scatter models assume that forward-scattered radiation dominates back-scattered radiation and is coherent with the specular beam. At present there is no wavefront sensing and control model per se. Instead, a WFSC performance limit is assumed, consistent with results obtained in the HCIT testbed extrapolated to a more stable environment. 108
Plan for Technology Development Dynamic error budget terms (jitter and thermal terms) are calculated using linear ray-trace aberration and beam-walk sensitivity matrices combined with the Fourier-plane coronagraph performance model. This model is used to evaluate the contrast leakage related to Zernike aberrations. These models lead to optical surface and structural stability requirements, from which thermal stability, structural damping and isolation are derived by the integrated modeling team. Table 7-1. Dynamic and Static Error Budget Schedule Planned Completion Date Planned Activities Performance Targets Pre-Phase A Sensitivity matrix validation using HCIT Verification to 10-20% of contrast sensitivity Near-field diffraction modeling and mask imperfection modeling Develop full static error budget that describes the contrast in an initial state and the contrast after WFSC using a pair of DMs in a Michelson configuration Inclusions of wavelength dependent design parameters, random mask errors, and systematic errors Ability to model individual static WFE contributions at the 10 -12 contrast level Phase A Phase B Validation of static WFE budget using HCIT Iterative refinement of error budget in conjunction with end-to-end modeling activities Validation of dynamic error budget using other testbeds 109
Page 1 and 2:
JPL Publication 05-8 Technology Pla
Page 3:
TECHNOLOGY PLAN TERRESTRIAL PLANET
Page 6 and 7:
Recent Highlights Technical progres
Page 8 and 9:
Figure i-4. Deformable mirror deliv
Page 10 and 11:
Table of Contents Approvals........
Page 12 and 13:
7.5.2 Precision Hexapod............
Page 14 and 15:
Chapter 1 Figure 1-1. Artist's impr
Page 16 and 17:
Chapter 1 interferometry, continues
Page 18 and 19:
Chapter 1 Back end coronagraph opti
Page 20 and 21:
Chapter 1 Surrounding the whole tel
Page 22 and 23:
Chapter 1 Pol. BS fold/steering Mic
Page 24 and 25:
Chapter 1 1.6.5 Sunshield The teles
Page 26 and 27:
Chapter 1 expected architecture dow
Page 28 and 29:
Chapter 1 Table 1-3. TPF-C Technolo
Page 30 and 31:
Chapter 1 3B: Demonstrate, using th
Page 32 and 33:
Chapter 2 2 Error Budgets 2.1 Contr
Page 34 and 35:
Chapter 2 Error Budget Validation G
Page 36 and 37:
Chapter 2 Further, it is shown that
Page 38 and 39:
Chapter 2 Table 2-1. Requirement on
Page 40 and 41:
Chapter 3 3 Optics and Starlight Su
Page 42 and 43:
Chapter 3 are in progress with cont
Page 44 and 45:
Chapter 3 Figure 3-5. Coronagraph s
Page 46 and 47:
Chapter 3 (though not light-weight
Page 48 and 49:
Chapter 3 Table 3-3. ITT Metrology
Page 50 and 51:
Chapter 3 observations. The time it
Page 52 and 53:
Chapter 3 vacuum-compatible, low-po
Page 54 and 55:
Chapter 3 blank size. Westerhoff et
Page 56 and 57:
Chapter 3 configurations, performan
Page 58 and 59:
Chapter 3 Figure 3-10: Plots showin
Page 60 and 61:
Chapter 3 The wavefront quality of
Page 62 and 63:
Chapter 3 Figure 3-13. Optical layo
Page 64 and 65:
Chapter 3 algorithms have limitatio
Page 66 and 67:
Chapter 3 simulated star source is
Page 68 and 69:
Chapter 4 Figure 4-1. Overview of t
Page 70 and 71: Chapter 4 enclosures, and stable la
Page 72 and 73: Chapter 4 facilities from which dat
Page 74 and 75: Chapter 4 Figure 4-5. Microslip Tri
Page 76 and 77: Chapter 4 Figure 4-7. Calibration o
Page 78 and 79: Chapter 4 Figure 4-8. Comparison of
Page 80 and 81: Chapter 4 4.2 Subsystem and System
Page 82 and 83: Chapter 4 Figure 4-11. Schematic of
Page 84 and 85: Chapter 4 Figure 4-12. Fine guiding
Page 86 and 87: Chapter 4 (5) The Fine Steering Mir
Page 88 and 89: Chapter 4 Third, precise thermal co
Page 90 and 91: Chapter 4 giving confidence that fl
Page 92 and 93: Chapter 4 surface polish is nonethe
Page 94 and 95: Chapter 5 TPF-C is planning a suite
Page 96 and 97: Chapter 5 engineering judgment (i.e
Page 98 and 99: Chapter 5 categories, in reality ea
Page 100 and 101: Chapter 5 Table 5-3. Validation of
Page 102 and 103: Chapter 5 5.6.1 Modeling Methodolog
Page 104 and 105: Chapter 5 strength of computer simu
Page 106 and 107: Chapter 6 6 Instrument Technology a
Page 108 and 109: Chapter 6 Figure 6-1. Detailed conc
Page 110 and 111: Chapter 6 The first method is self-
Page 112 and 113: Chapter 6 super computers and is us
Page 114 and 115: Chapter 7 7 Plan for Technology Dev
Page 116 and 117: Chapter 7 Figure 7-1. TPF-C Technol
Page 118 and 119: Chapter 7 Improvements to the DM ov
Page 122 and 123: Chapter 7 7.4 Optics and Starlight
Page 124 and 125: Chapter 7 7.4.2 Apodizing Masks and
Page 126 and 127: Chapter 7 7.4.4 Wavefront Sensing a
Page 128 and 129: Chapter 7 7.4.6 Transmissive Optics
Page 130 and 131: Chapter 7 7.4.8 Scatterometer Scope
Page 132 and 133: Chapter 7 7.5 Structural, Thermal,
Page 134 and 135: Chapter 7 7.5.3 Precision Structura
Page 136 and 137: Chapter 7 model of TPF-C and should
Page 138 and 139: Chapter 7 7.5.6 Secondary Mirror To
Page 140 and 141: Chapter 7 7.5.8 Sub-scale EM Sunshi
Page 142 and 143: Chapter 7 7.6 Integrated Modeling a
Page 144 and 145: Chapter 7 7.7.3 Advanced Concepts:
Page 146 and 147: Chapter 8 134
Page 148 and 149: Appendices Appendix B: TPF-C Detail
Page 150 and 151: Appendices Appendix D: TPF-C Techno
Page 152 and 153: Appendices Appendix F: Acronym List
Page 154: Appendices RWA SAO SBIR SIM SM SMFA
show all

TPF-C Technology Plan - Exoplanet Exploration Program - NASA

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?