- Page 1: Post Flight Analysis — Final Repo
- Page 5 and 6: Table of ContentsPreface . . . . .
- Page 8 and 9: 6.8 Sources and References . . . .
- Page 10 and 11: 11 Telescope Readout Subsystem (TRE
- Page 12 and 13: 14 Data Collection, Processing & An
- Page 14 and 15: xiv March 2007 Table of Contents
- Page 16 and 17: Figure 3-4. The GP-B dewar—one of
- Page 18 and 19: Figure 8-5. The Seasons of GP-B . .
- Page 20 and 21: Figure 11-20. Pointing angle differ
- Page 22 and 23: Figure 14-9. In the Anomaly Room, t
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- Page 26 and 27: Table 13-3. GP-B payload magnetomet
- Page 28 and 29: xxviiiMarch 2007
- Page 30 and 31: 2 March 2007 Chapter 1 — Executiv
- Page 32 and 33: facility, it was necessary to recas
- Page 34 and 35: spacetime around with them as they
- Page 36 and 37: After years of work and the inventi
- Page 38 and 39: axis of a gyroscope rotor changes i
- Page 40 and 41: Figure 1-8. Clockwise, from top lef
- Page 42 and 43: “management experiment.” This w
- Page 44 and 45: Attitude-Control Gyroscopes. Two pa
- Page 46 and 47: Any significant deviation from “g
- Page 48 and 49: established, ranging from Level 1 (
- Page 50 and 51: 1.14 The Broader Legacy of GP-BAt l
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24 March 2007 Chapter 2 — Overvie
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Figure 2-1. GP-B Historical Time Li
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Applied Physics Laboratory, of the
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William Fairbank once remarked: “
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In Einstein’s view, space and tim
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y a mere 1.1 inches. You can see th
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Figure 2-10. Schematic diagram of t
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Figure 2-12. Final assembly of the
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Sun Shield. The sun shield is a lon
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2.1.8 The Broader Legacy of GP-BWhe
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2.3 Spacecraft SeparationThe Solar
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Flight Anomalies.) Furthermore, a d
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Table 2-2. Weekly summary of IOC ac
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2.4.3.2 Guide Star AcquisitionAbout
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A second mass trim operation had be
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On Friday, 2 July 2004, the spin ra
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Low temperature bakeout was first p
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2.5.1.3 Lockheed Martin Team Phase-
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Monthly Highlights of the GP-B Scie
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2.6.1 Overview of the Calibration P
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Weekly Highlights of the GP-B Final
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66 March 2007 Chapter 3 — Accompl
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It was in this pristine, near-zero
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Each quartz rotor is coated with a
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Figure 3-3. Functional diagram of a
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Based on data from the on-board tel
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Ideally, the telescope should have
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Figure 3-9. Schematic diagram of st
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used. The star trackers are essenti
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Result: By using the porous plug, w
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Solution: Create a tetrahedral lapp
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Constraint 2: The exhaust tube must
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Result: The on-orbit gyroscope spin
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spacecraft's subsystems for the dur
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Constraint 3: Keep the spacecraft p
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Technology Category Specific Implem
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96 March 2007 Chapter 4 — GP-B On
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Any significant deviation from “g
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packages, one for each Ping load an
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In addition to these software packa
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Table 4-6. Features & benefits of W
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This software added considerable ef
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It is said that “an experiment is
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Table 4-10. Significant Events/Sour
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Figure 4-5. Pictorial depiction of
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Figure 4-7. Eta-Average Error Assoc
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4.4.4.2 OD Using SLR DataFigure 4-9
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4.4.5 ConclusionsFigure 4-11. Compa
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Overall, the storage issues did not
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Table 4-11. ITF equipment listEQUIP
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124 March 2007 Chapter 5 — Managi
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5.2 Overview of GP-B Anomalies in O
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Figure 5-1. Anomaly Review Team Org
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5.3.3.1 Anomaly Investigation and R
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5.3.5 Anomaly Identification and Re
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5.4.3 Risk Management ApproachThe r
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Table 5-1. Summary of Open GP-B ris
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138 March 2007 Chapter 5 — Managi
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140 March 2007 Chapter 6 — The GP
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3. Payload Integration, Testing and
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Figure 6-1. Clockwise from top left
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MSFC conducted an in-house Phase A
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It is important to note that from t
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6.3.1 Incremental PrototypingThe pe
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alignment, and act as an accelerome
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Figure 6-9. The Lockheed Martin GP-
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Furthermore, a fourth electronic sy
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positive thermal connections betwee
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astrophysics/cosmology. Many of the
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Figure 6-10. MSFC Program Managers/
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As described in Chapter 2, the flig
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6.7 Some Observations on the Manage
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168 March 2007 Chapter 6 — The GP
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170 March 2007 Chapter 7 — Attitu
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7.1.2 Vehicle ATC ModesThere are es
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The output of the pressure transduc
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Figure 7-3. Science Telescope Compo
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Figure 7-5. Pitch and Yaw Pointing
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Figure 7-7. Magnitude of the roll r
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Changing the method by which the gy
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7.3.3 Drag-Free Control SystemFigur
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7.3.3.1 DFS - PerformanceThe GP-B d
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Figure 7-15. Mass flow effects of a
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7.5.2 Successful recovery from mult
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If the vehicle control system were
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accomplish this, the ARPs are mount
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7.5.6.1 South Atlantic AnomalyProto
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Figure 7-23. Effects on telescope p
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200 March 2007 Chapter 7 — Attitu
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202 March 2007 Chapter 8 — Other
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Figure 8-2. Block Diagram of CDH co
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8.1.1.4 WATCH DOG TIMERFigure 8-4.
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of eclipses each day (approximately
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Figure 8-8. GSS1 Temperature Trends
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Figure 8-10. Forward Dewar Vacuum S
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The Gravity Probe B spacecraft has
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Figure 8-13. Forward -X Thruster Te
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gaFigure 8-15. Aft -X Thruster Temp
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Because there are only two SQUID br
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Because the specifications for SRE
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8.3.2 Critical Mission RequirementT
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Figure 8-19 is a plot of the power
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Battery Performance Summary:Figure
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Figure 8-23. Solar Array Temperatur
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8.3.10 ConclusionThe electrical pow
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8.4.1 TDRSS OperationsFigure 8-28.
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Figure 8-30. Xpndr-A STDN (green),
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Figure 8-32. Plot of TDRS AGC vs Te
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The FSW also met its subsystem leve
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Appendix E, Flight Software Applica
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Table 8-4. SCRs Addressed in On-orb
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The software and macro changes resu
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Figure 8-38 below is an excerpt fro
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Figure 8-40. A-side CCCA Single Bit
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Figure 8-43. A-side CCCA Single Bit
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When single MBEs did not result in
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256 March 2007 Chapter 9 — Gyro S
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9.1 GSS Hardware DescriptionFigure
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significantly reduces and thus pres
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9.1.11 Clock synchronizationThe aft
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Figure 9-8. Block diagram of the LQ
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direction (transverse to the space
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9.2.2.2 Spin-up SuspensionDuring sp
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Figure 9-16. Predicted and measured
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Figure 9-18. The GSS passes rotor c
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Figure 9-20. Representative drag-fr
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Table 9-1. GSS Science Mission Mode
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Table 9-3. GSW application source l
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The Design and Testing of the Gravi
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282 March 2007 Chapter 10 — SQUID
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ate uncertainty). Although we have
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All of the GP-B electronics have be
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10.3 Pre-Launch Ground-Based TestsW
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Figure 10-6. AC Magnetic Shielding
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Figure 10-8. Temperature Error of S
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Figure 10-10. Quiescent SQUID Noise
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Analog control loops on the electro
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The science support applications ru
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Table 10-7. SSW application source
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Table 10-7. SSW application source
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Table 10-7. SSW application source
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Table 10-7. SSW application source
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308 March 2007 Chapter 11 — Teles
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Figure 11-1. Block diagram of TRE a
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Additionally, the warm electronics
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Figure 11-3. CLL switch states duri
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Table 11-3. Dates and UTC times whe
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Figure 11-7. Low Gamma Angle Data S
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s N+w i= sign+w i++−+−w i−w i
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expression, which otherwise on a po
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Figure 11-14. Y axis, B side RMS po
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Figure 11-17. X axis, B side curren
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Figure 11-20. Pointing angle differ
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Figure 11-24. Scaled summed current
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Figure 11-26 through Figure 11-29 s
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334 March 2007 Chapter 12 — Cryog
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12.2 Temperature / pressure control
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control the space vehicle without t
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Figure 12-3. Helium flow rate predi
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helium at 1.8 K. It does not appear
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Figure 12-6. Flow meter and ATC flo
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were generally within a day or so o
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shields) and subsequent instability
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350 March 2007 Chapter 12 — Cryog
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352 March 2007 Chapter 13 — Other
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Figure 13-2. ECU-operated heaters i
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13.1.3.1 Vatterfly Valve Operations
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13.1.3.7 Payload MagnetometersThe E
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Figure 13-11. ECU performance durin
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As we entered the second month of o
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During the last month of IOC, prepa
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Figure 13-19. ECU heater activity d
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Table 13-1. Proton monitor channel
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Figure 13-21. Proton Monitor data i
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In November, 2004 there was a large
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Figure 13-28 shows a correlation th
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13.3.1 About the MagnetometersFigur
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13.3.2 Other Applications for Paylo
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Figure 13-35. GPS Antennae Field of
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Figure 13-37. Master Antenna Switch
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Figure 13-39. Time difference betwe
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13.4.6 On-Orbit ResultsThe GPS comp
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and velocity values erroneously cal
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E. G. Lightsey, C. E. Cohen, B. W.
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Figure 13-45. A Bottom View of the
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Figure 13-48. The GMA configuration
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Table 13-10. Summary for Helium Gas
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398 March 2007 Chapter 14 — Data
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a relatively slow data rate, so we
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Figure 14-4. NASA ground stations a
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electronic components to recover fr
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By a process of elimination, the GP
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A special room in the GP-B Mission
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Starting on 3 December 1725, Bradle
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seemed that aberration of starlight
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14.1.6 Telescope Dither—Correlati
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14.1.6.3 The Telescope Dither Patte
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amplifications. Thus, in addition t
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14.2.2 Independent Data Analysis Te
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monthly time scales. Though only sh
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424 March 2007 Chapter 15 — Preli
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Figure 15-2. A diagram of the GP-B
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15.4 The Two Surprises and Their Im
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Near Zeroes.) The exception that we
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Figure 15-8. A slide from the GP-B
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Figure 15-9. A poster on the effect
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electrostatic patches, located at o
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Last summer (2006), Mac Keiser devi
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440 March 2007 Chapter 15 — Preli
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442 March 2007 Chapter 16 — Lesso
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16.1.1.3 Flight science downlink da
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Description of the GP-B experience:
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Lessons:1. Perform all tests with a
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Description of the GP-B experience:
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Figure 16-1. Six interacting transl
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16.1.3.2 Training and certification
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Description of the GP-B experience:
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Below is an edited summary of six a
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460 March 2007 Chapter 16 — Lesso
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462 March 2007 Appendix A — Gravi
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Apogee altitude659.1 km (409.6 mile
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466 March 2007 Chapter B — Spacec
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Gravity Probe B — Post Flight Ana
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470 March 2007 Appendix C — Weekl
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16 April 2004—Vehicle is Prepared
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The electrical power system is full
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4 JUNE 2004—MISSION UPDATE: DAY 4
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SQUIDs to detect their rotation spe
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17 JULY 2004—MISSION UPDATE: DAY
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indicate that we have reduced the t
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C.4 Science Mission Phase: 8/27/04
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• GP-B also has an independent da
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free suspension parameters to de-tu
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We have received inquiries about a
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One of the effects of geomagnetic s
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egan transmitting, one-by-one, stat
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28 JANUARY 2005—GRAVITY PROBE B M
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magnetic pole. This event triggered
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8 APRIL 2005—GRAVITY PROBE B MISS
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On Tuesday afternoon (19-April), GP
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Norway or through the NASA space ne
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Dewar Temperature: 1.82 kelvin, hol
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visitors on a tour of the GP-B faci
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test, we are planning on running fi
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contractor at the Goddard Space Fli
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On Wednesday, we visited the star H
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Gyro Suspension System (GSS): All 4
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The helium in the dewar has now sur
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the all the spacecraft status data.
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522 March 2007 Appendix D — Summa
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Figure D-2 below shows the distribu
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DateSeveritySubtypeTitle Descriptio
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DateSeverity24 26-Apr-04 Obs F Nois
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DateSeverity40 11-May-04 Obs T Dwel
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DateSeveritySubtypeTitle Descriptio
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DateSeverity68 16-Jun-04 Medium Dec
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DateSeverity84 13-Jul-04 Obs F Slig
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DateSeveritySubtypeTitle Descriptio
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DateSeverity116 26-Sep-04 Obs F SG3
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DateSeverity132 20-Dec-04 Obs F Unc
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DateSeverity149 5-Mar-05 Obs T Few
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DateSeverity169 04-Jun-05 Obs F MBE
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DateSeverity191 04-Oct-05 Obs A GSS
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550 March 2007 Appendix E — Fligh
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ReqIDLevel 1CSCDMP DataMgmtProcessi
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ReqIDLevel 1CSCLevel2 CSC Level 3 C
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ReqIDLevel 1CSCLevel2 CSC Level 3 C
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ReqIDLevel 1CSCLevel2 CSC Level 3 C
- Page 588 and 589:
ReqIDLevel 1CSCSRM Solid StateRecor
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ReqIDLevel 1CSCLevel2 CSC Level 3 C
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ReqIDLevel 1CSCLevel2 CSC Level 3 C
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ReqIDLevel 1CSCSRP SafemodeResponse
- Page 596 and 597:
ReqIDLevel 1CSCGUP GSS Processing g
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570 March 2007 Appendix F — Acron
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AcronymDefinitionAcronymDefinitionB
- Page 602 and 603:
AcronymDefinitionAcronymDefinitionD
- Page 604 and 605:
AcronymDefinitionAcronymDefinitionF
- Page 606 and 607:
AcronymDefinitionIRUInertial Refere
- Page 608 and 609:
AcronymDefinitionAcronymDefinitionM
- Page 610 and 611:
AcronymPMPMAPMCPMEPMETPMSPMSUPNPoPO
- Page 612 and 613:
AcronymSCMOSCMTSCNSCPASCPMSCRSCSASC
- Page 614 and 615:
AcronymDefinitionAcronymDefinitionT
- Page 616:
588 March 2007 Appendix F — Acron