MISSION PLAN - PDS Small Bodies Node

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Coma images will be acquired primarily during the Far Encounter subphase of the mission. Images obtained during this subphase will have resolutions of 31 to 3000 km per pixel. Seven filters will be used at each science imaging episode and will be sent down at the designated communication times. Approximately 210 images (30 per filter, which allows No of pixels (1-D) 1E+5 1E+4 1E+3 1E+2 1E+1 1E+0 28.7 26.1 23.4 coma nucleus Image Resolution (km/pixel) 20.8 1E-1 -24 -22 -20 -18 -16 -14 -12 -10 -8 -6 18.2 Time From Encounter (hours) 15.6 13.0 10.4 Assume ~ 100,000 km radius coma and ~2 km radius nucleus 7.8 b. Near Encounter 1000 5.9 5.2 4.6 Image Resolution (km/pixel) 3.9 3.3 2.6 2.0 1.3 0.7 0.009 No of pixels (1-D) Assume ~2 km radius nucleus 100 10 nucleus 1 0 -300 -270 -240 -210 -180 -150 -120 -90 -60 -30 0 Time From Encounter (minutes) No of pixels (1-D) Image Resolution (m/pixel) 87 66 44 23 8.8 23 44 66 87 500 400 Assume ~2 km radius nucleus phase 300 200 100 nucleus pixels 0 -5 -4 -3 -2 -1 0 1 2 3 4 5 Time From Encounter (minutes) 180 150 120 90 60 30 0 Phase Angle (deg) c. Close Encounter Figure 6.2-1 Wild-2 Encounter Comet Profile 74
image summing on the ground to correct for spacecraft stability during imaging) will be acquired twice per week until E-7 d. At E-7 d, this level of imaging increases to 1 set per day. This schedule offers the opportunity to develop full color movies of the evolving coma and make any corrections to the comet dust flux model. From E-100d to E-1d, the size of the coma images will vary from several pixels to virtually filling the camera FOV. The detailed strategy for compression and windowing for science images will be image dependent and described in image request files, but based on a data rate capability of 500 bps (science allocation) and the telemetry schedule provided in Figure 6.1-2, STARDUST is expected to be able to transmit more than 40 full-frame image equivalents at 2:1 compression. This would far exceed the nominal imaging requirement. The images taken during the first part of the encounter phase may be used to assess the comet activity level. If deemed unsafe for the spacecraft, a large deflection maneuver (several hundred to 1000 km) may be incorporated in the TCM planned at E-2 d. At E-1 d, within the Near Encounter subphase, the coma image is assumed to fill the camera field-of-view and, the nucleus becomes discernible (fraction of a pixel). Viewing of the coma near the nucleus for finer details now becomes possible. These images are expected to have resolutions ranging from 7 to 31 km/pixel. Imaging continues through to E-12 h. From E-12 h to E-5 h, there is no specific plan to acquire additional images so as to permit preparation and execution of the final pre-encounter TCM (E-6 h), if needed. Any additional images taken during this period may contribute to the final targeting and to risk avoidance. 6.2.2.2 Nucleus Images Near-continuous imaging and real-time transmission of imaging data are planned from E- 5 hours to E-5 min, within the Close Encounter Subphase. Assuming 8 images per set and 2:1 compression, Table 6.2-1 summarizes the image size that can be transmitted during these individual periods as a function of bits per pixel and number of sets. Table 6.2-1 Allowable Near Encounter Image Size Number of Sets Number of Images Image Size (pixels) 12 bits per pixel Image Size (pixels) 8 bits per pixel 1 8 751 x 751 920 x 920 2 16 531 x 531 651 x 651 3 24 434 x 434 531 x 531 4 36 376 x 376 460 x 460 Two spacecraft functions that allow the nucleus images to remain in the camera field-ofview are initiated during this period of time. A one degree-of-freedom imaging mirror allows image motion compensation and protects the camera optics from the cometary dust hazard. Centroiding of the comet image is used in conjunction with the imaging 75
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STARDUST MISSION PLAN February 1, 1
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STARDUST MISSION PLAN Edward A. Hir
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Table of Contents Table of Contents
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10.1.1 Spacecraft Attitude History
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Figure 6.2-1.a Wild-2 Encounter Com
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Table 10.1-3 Spacecraft Attitude Pr
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kg km L L/O Kilogram Kilometer Laun
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Change Log Change Letter Date Affec
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1.0 Introduction 1.1 Purpose The pu
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2.0 Mission Overview 2.1 Mission Ob
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Fairing STARDUST Second Stage Star3
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propulsive maneuvers. To avoid pote
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The STARDUST camera is necessary to
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of-view is smaller, as described in
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Backshell Avionics Deck Parachute C
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Earth Gravity Assist 01/15/01 Earth
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Cruise 2 (Earth-Wild-2) ISP Collect
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2.3.2 Launch Period Strategy 2.3.2.
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Table 2.3-2 Baseline Mission Parame
Page 41 and 42: Table 2.3-2 Baseline Mission Parame
Page 43 and 44: *B plane angle (deg) -41.051 -40.96
Page 45 and 46: 2.3.2.2 ∆V Budget The total ∆V
Page 47 and 48: Accumulation of Radiation with Time
Page 49: Table 2.3-4 STARDUST Alternate-2 Mi
Page 52 and 53: calculations will require more deta
Page 54 and 55: 10 17 10 16 10 15 10 14 10 13 Fluen
Page 56 and 57: 8 10 flare, no shielding 6 10 4 10
Page 58 and 59: The orbit of comet Wild-2 was drast
Page 60 and 61: • Dust density = Nucleus density
Page 62 and 63: 2.4.4 Interstellar Dust Science Pla
Page 64 and 65: Launch Initial Acquisition TCM-1 Ac
Page 66 and 67: Stage II ignition t=277.5 s h=66.4
Page 68 and 69: Special ‘coming-off-theperiscope
Page 70 and 71: phases are very similar to the stan
Page 72 and 73: presented in tables contained in Ap
Page 74 and 75: Figure 4.2-4.b. Beta Meteoriod Impa
Page 76 and 77: 180 Off-SEP & ORBIT normal angle (d
Page 78 and 79: 2/6 launch Events Attitude 74 days
Page 80 and 81: yaw, while continuing to meet solar
Page 82 and 83: Time Image Description images pixel
Page 84 and 85: (EGA-60d to +30d) TCM 4 (EGA-60 d)
Page 86 and 87: 6.0 Wild-2 Encounter Phase (E-100 t
Page 88 and 89: the installation of the HGA. The su
Page 90 and 91: Date Sept-03 Oct-03 Nov-03 Dec-03 J
Page 94 and 95: mirror via a simple one dimension t
Page 96 and 97: The cross track error corresponds t
Page 98 and 99: 14 12 10 24 km 3 sigma distance 1 s
Page 100 and 101: All 34-m HEF except selective 70-m
Page 102 and 103: SRC Entry / Descent Atmospheric Ent
Page 104 and 105: Two TCM’s are planned within this
Page 106 and 107: It is important to note that, other
Page 108 and 109: 8.0 Planetary Protection The object
Page 110 and 111: Earth-Probe Range Sun-Earth-Probe A
Page 112 and 113: 9.1 Mission Data Set (cont) 14.00 E
Page 114 and 115: 14.00 MOON-PROBE RANGE Launch Phase
Page 116 and 117: 180.00 SUN-EARTH-PROBE ANGLE EGA Ph
Page 118 and 119: 180.00 SUN-PROBE-MOON ANGLE EGA Pha
Page 120 and 121: 180.00 SUN- WILD-2 -PROBE ANGLE Enc
Page 122 and 123: Cone & Clock Angles of Wild-2 Cone
Page 124 and 125: 180 Cone & Clock Angles of Sun 180
Page 126 and 127: 9.4 Wild-2 Encounter Data Set (cont
Page 128 and 129: 16.00 MOON-PROBE RANGE Return Phase
Page 130 and 131: 10.0 Appendix B: Unbalanced Attitud
Page 132 and 133: spacecraft attitude when the spacec
Page 134 and 135: Time From Launch Off-sun Angle (deg
Page 136 and 137: Acceleration (1E-11 km/s/s) 12 10 8
Page 138 and 139: +z, yaw +y, pitch +x, roll Figure 1
Page 140 and 141: ** vectors evaluated at the time of
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Rgt Ascen (deg) [eme'2000] 360 300
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Table 10.2-6 Communications Schedul
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Table 10.2-6 Communications Schedul
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031228 19180 0 031229 19180 0 03123
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TRAJECTORY CORRECTION MANEUVERS EVE
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2453509.10737773 50518. 143437. 229
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50204. 3437. 2189.12 outb SEP = 3 d
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Table 12-1 ISP #1 Collection Period
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Table 12-2 ISP #2 Collection Period
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Table 12-4 ISP #2 Spacecraft Attitu
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Table 12-5 CIDA #1 Collection Perio
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Table 12-6 CIDA #2 Collection Perio
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908.000 41.659 20.000 9.272 175.100
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Table 12-8 CIDA #1 Spacecraft Attit
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Table 12-9 CIDA #2 Spacecraft Attit
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Table 12-11 CIDA #3 Solar Conjuncti
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13.0 Appendix E: PRD Traceability M
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