TPF-I SWG Report - Exoplanet Exploration Program - NASA

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C HAPTER 5 5.3.2 Combiner Spacecraft On the beamcombiner spacecraft, the beam is first compressed from approximately 150 mm in diameter to 30 mm in diameter, and it passes through a multistage delay line. Following the delay line, it enters the adaptive nuller where the phase and amplitude are adjusted across the spectral band. After the adaptive nuller it enters a switch, which allows selection of T1–T2, T3–T4 or T1–T3, T2–T4 beam combination. Then it enters the nuller itself, at which point the fringe tracking light is separated from the science beams. After nulling and interfering the beams at the appropriate phases, the science light enters a single spatial mode fiber, and then it is dispersed spectrally before striking the science detector. Numerous beam train systems exist to maintain and adjust the alignment and the collector spacecraft phase of the beams. These will be discussed below. Cold Sunshade Deployment Booms Stray Light Baffle Payload Cryo Radiator Cryogenic Nulling Beam Combiner Five Layer Sunshade Body-Fixed Solar Arrays Warm Sunshade Deployment Booms 15.3 m Thruster Modules Spacecraft Bus Gimballed High Gain Antenna Figure 5-4. Combiner Spacecraft 102
<strong>TPF</strong>-I F L I G H T B ASELINE D ESIGN 5.3.3 Telescope Assembly The telescope design is a three-mirror anastigmat design using conic sections: the primary is an ellipse; the secondary is a hyperbola; and the tertiary is an ellipse. After reflection from the secondary, the beam passes through a hole in the center of the primary and is folded into a plane beneath the primary. The primary mirror has a diameter of 4.0 m, and the secondary has a diameter of 0.3 m, giving an obscuration ratio of ~0.023, excluding spiders and mounts. An offset field angle used in previous designs was eliminated to reduce the number of differences between the left and right sets of collector telescopes. The new design was also required to have a very uniform wavefront performance across the field of view. This is to ensure that as the telescope drifts in space, the Strehl ratio remains the same, so that the coupling onto the single mode fiber at the end of the beamtrain does not vary. This ensures that the null depth will remain constant during the observation. It was not considered desirable to continuously operate the DM to compensate for these small wavefront changes. A mirror placed between the tertiary and the DM acts as a field of regard (FOR) mirror; it tilts to bring light from a chosen star into the main beam path and maintains that alignment continuously during observations. Figure 5-5. Beam transits between spacecraft are made as nearly as possible across diameters. The beam layout ensures that no angle changes as the formation expands. The layout also gives maximum shading from the sunshields; each mirror looks across the width of the spacecraft. 5.3.4 Beam Train Optics Beneath the primary mirror, the beam strikes a fold mirror that tilts to bring the starlight into the main beam path. Next it strikes the third mirror of the three-mirror telescope and the FOR dichroic mirror. Behind this dichroic mirror are an alignment beam launcher and a metrology beam retro-reflector. Next, the beam strikes the DM, which corrects static wavefront errors. This pair of mirrors (the DM and the FOR) is controlled from the output of sensors placed behind the WFS/FGS dichroic, next in line, which separates out some light from the star for pointing and wavefront sensing. Next the beam is recollimated and transmitted to the top of the spacecraft. An active pointing mirror relays it to the next spacecraft. 103
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JPL Publication 07-1 Terrestrial Pl
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Abstract Over the past two years, t
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Acknowledgements Twenty-two represe
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Table of Contents 1 Introduction...
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4.8.3 Post-Nulling Calibration.....
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6.4.5 Double Fourier Interferometry
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I NTRODUCTION 1 Introduction Over 2
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I NTRODUCTION et al. 2004), and res
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I NTRODUCTION Standard Interferomet
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I NTRODUCTION 1.4 References Angel,
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C HAPTER 2 0.7 to 1.5 AU scaled by
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C HAPTER 2 Table 2-2. Illustrative
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C HAPTER 2 Classical interferometry
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C HAPTER 2 trivial in the absence o
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C HAPTER 2 Figure 2-3. Simulated mi
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C HAPTER 2 would be in atmospheres
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C HAPTER 2 Figure 2-6. The mid-infr
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C HAPTER 2 Lines of constant stella
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C HAPTER 2 presence of zodiacal clo
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C HAPTER 2 S EZ 2π ∫ θ max ∫
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C HAPTER 2 Figure 2-11. Observation
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C HAPTER 2 Figure 2-12. Models of t
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C HAPTER 2 Beichman, C. A., Fridlun
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C HAPTER 2 2.7.4 Suitable Targets E
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C HAPTER 2 Reach, W. T., Franz, B.
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C HAPTER 3 3.1.1 Darwin/TPF-I Prope
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C HAPTER 3 clouds or an OB associat
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C HAPTER 3 Figure 3-3. Three possib
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C HAPTER 3 the circumstellar disk,
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C HAPTER 3 Figure 3-6. (Left panel)
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C HAPTER 3 Continuum interferometry
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Page 68 and 69: C HAPTER 3 3.3 Conclusions Darwin/T
Page 70 and 71: C HAPTER 3 Nguyen, H. T., Kallivaya
Page 73 and 74: D ESIGN AND A R C H I T E C T U R E
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Page 114 and 115: C HAPTER 5 Heavy launch vehicle. Th
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Page 128 and 129: C HAPTER 5 Figure 5-15. TPF-I Fligh
Page 130 and 131: C HAPTER 5 secondary mirror along t
Page 132 and 133: C HAPTER 5 a) c) b) d) IWA = 43 mas
Page 134 and 135: C HAPTER 5 planets found. Figure 5-
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Page 138 and 139: C HAPTER 5 5.8.4 Angular Resolution
Page 140 and 141: C HAPTER 5 Table 5-3. Angular Resol
Page 142 and 143: C HAPTER 5 The optimization works b
Page 145 and 146: T E C H N O L O G Y R OADMAP FOR TP
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T E C H N O L O G Y R OADMAP FOR TP
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F UTURE D EVELOPMENTS 7 Preparatory
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F UTURE D EVELOPMENTS • To comple
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F UTURE D EVELOPMENTS Table 7-1. Pr
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D ISCUSSION AND C ONCLUSION 8 Discu
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Appendices 167
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T E C H N O L O G Y A DVISORY C O M
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F L I G H T S YSTEM C ONFIGURATION
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F L I G H T S YSTEM C ONFIGURATION
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A PPENDIX C 2. Identical FACS fligh
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A PPENDIX C 2. Recall that the coef
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A PPENDIX C Once the formation has
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A PPENDIX C Figure C-3. Example of
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A PPENDIX C Figure C-4. FAST Flight
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A PPENDIX C The “true” time of
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A PPENDIX C References Cohen, S., a
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A PPENDIX D DC DCB DM DM DOCS DOD D
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A PPENDIX D NaCl NAR NASA NASTRAN N
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A PPENDIX E Appendix E TPF-I Review
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A PPENDIX F Alice Quillen, Universi
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A PPENDIX F Figure 3-1 - Original f
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TPF-I SWG Report - Exoplanet Exploration Program - NASA

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