List of Figures

View Image Figure 2.1:
Trajectories of Pioneer 10 and 11 during their primary missions in the solar system (from [126]). The time ticks shown along the trajectories and planetary orbits represent the distance traveled during each year.
View Image Figure 2.2:
Ecliptic pole view of the Pioneer 10 and Pioneer 11 trajectories during major parts of their extended missions. Pioneer 10 is traveling in a direction almost opposite to the galactic center, while Pioneer 11 is heading approximately in the shortest direction to the heliopause. The direction of the solar system’s motion in the galaxy is approximately towards the top. (From [27].)
View Image Figure 2.3:
A drawing of the Pioneer spacecraft. (From [292].)
View Image Figure 2.4:
Pioneer 10 and 11 internal equipment arrangement. (From [292].)
View Image Figure 2.5:
The SNAP-19 RTGs used on Pioneer 10 and 11 (from [350]). Note the enlarged fin structure. Dimensions are in inches (1” = 2.54 cm).
View Image Figure 2.6:
Overview of the Pioneer 10 and 11 electrical subsystem (from [292]).
View Image Figure 2.7:
Pioneer 10 power budget on July 25, 1981, taken as an example. Power readings that were obtained from spacecraft telemetry are indicated by the telemetry word in the form Cnnn. The discrepancy between generated power and power consumption is due to rounding errors and uncertainties in the nominal vs. actual power consumption of various subsystems.
View Image Figure 2.8:
An overview of the Pioneer 10 and 11 propulsion subsystem (from [292]).
View Image Figure 2.9:
Location of thermal sensors in the instrument compartment of the Pioneer 10 and 11 spacecraft (from [292]). Platform temperature sensors are mounted at locations 1 to 6. Some locations (i.e., end of RTG booms, propellant tank interior, etc.) not shown.
View Image Figure 2.10:
The Pioneer 10 and 11 thermal control louver system, as seen from the aft (–z) direction (from [292]).
View Image Figure 2.11:
Louver blade angle as a function of platform temperature (from [385]). Temperatures in ° F ([° C] = ([° F]–32) × 5/9).
View Image Figure 2.12:
Louver structure heat loss as a function of platform temperature (from [385]). Temperatures in ° F ([° C] = ([° F]–32) × 5/9).
View Image Figure 2.13:
Louver assembly performance (from [385]). Temperatures in ° F ([° C] = ([° F]–32) × 5/9).
View Image Figure 2.14:
Changes in total RTG electrical output (in W) on board Pioneer 10 (left) and 11 (right), as computed using the missions’ on-board telemetry.
View Image Figure 2.15:
Propulsion tank pressure (in pounds per square inch absolute; 1 psia = 6.895 kPa) on board Pioneer 10. The three intervals studied in [27] are marked by roman numerals and separated by vertical lines.
View Image Figure 2.16:
On-board spin rate measurements (in rpm) for Pioneer 10 (left) and Pioneer 11 (right). The sun sensor used on Pioneer 10 for spin determination was temporarily disabled between November 1983 and July 1985, and was turned off in May 1986, resulting in a ‘frozen’ value being telemetered that no longer reflected the actual spin rate of the spacecraft. Continuing spot measurements of the spin rate were made using the Imaging Photo-Polarimeter (IPP) until 1993. The anomalous increase in Pioneer 11’s spin rate early in the mission was due to a failed spin thruster. Continuing increases in the spin rate were due to maneuvers; when the spacecraft was undisturbed, its spin rate slowly decreased, as seen in Figure 2.17.
View Image Figure 2.17:
Zoomed plots of the spin rate of Pioneer 11. On the left, the interval examined in [27] is shown; maneuvers are clearly visible, resulting in discrete jumps in the spin rate. The figure on the right focuses on the first half of 1987; the decrease in the spin rate when the spacecraft was undisturbed is clearly evident.
View Image Figure 2.18:
1 W radioisotope heater unit (RHU). From [292].
View Image Figure 2.19:
The emitted power (measured in dBm, converted to W) of the traveling wave tube transmitter throughout the mission, as measured by on-board telemetry. Left: Pioneer 10, which used TWT A (telemetry word C231). Right: Pioneer 11, initially using TWT A but switching to TWT B (telemetry word C214) early in its mission.
View Image Figure 2.20:
Platform temperatures (left) and RTG fin root temperatures (right) on board Pioneer 10. Temperatures in ° F ([° C] = ([° F]–32) × 5/9).
View Image Figure 2.21:
Platform temperatures (left) and RTG fin root temperatures (right) on board Pioneer 11. Temperatures in ° F ([° C] = ([° F]–32) × 5/9).
View Image Figure 3.1:
DSN facilities planned to be used by the Pioneer project in 1972 [334]. DSIF stands for Deep Space Instrumentation Facility, GCF is the abbreviation for Ground Communications Facility, while SFOF stands for the Space Flight Operations Facility.
View Image Figure 3.2:
DSN performance estimate throughout the primary missions of Pioneer 10 and 11. Adapted from [339].
View Image Figure 3.3:
The Doppler extraction process. Adapted from [374].
View Image Figure 3.4:
Block diagram of the DSN baseline configuration as used for radio Doppler tracking of the Pioneer 10 and 11 spacecraft. Adapted from [27101]. (IF stands for Intermediate Frequency.)
View Image Figure 3.5:
Typical tracking configuration for a Pioneer-class mission and corresponding data format flow [397].
View Image Figure 4.1:
Schematic overview of the radio navigation process. Adapted from [374].
View Image Figure 5.1:
Early unmodeled sunward accelerations of Pioneer 10 (from about 1981 to 1989) and Pioneer 11 (from 1977 to 1989). Adapted from [27], which contained this important footnote: “Since both the gravitational and radiation pressure forces become so large close to the Sun, the anomalous contribution close to the Sun in [this figure] is meant to represent only what anomaly can be gleaned from the data, not a measurement.”
View Image Figure 5.2:
Left: Two-way Doppler residuals (observed Doppler velocity minus model Doppler velocity) for Pioneer 10. On the vertical axis, 1 Hz is equal to 65 mm/s range change per second. Right: The best fit for the Pioneer 10 Doppler residuals with the anomalous acceleration taken out. After adding one more parameter to the model (a constant radial acceleration of aP = (8.74 ± 1.33) × 10− 10 m ∕s2) the residuals are distributed about zero Doppler velocity with a systematic variation ∼ 3.0 mm/s on a time scale of ∼ 3 months [27].
View Image Figure 6.1:
A drawing for the measurement concept chosen of the Deep Space Gravity Probe (from [106], drawing courtesy of Alexandre D. Szames). The formation-flying approach relies on actively controlled spacecraft and a set of passive test-masses. The main objective is to accurately determine the heliocentric motion of the test-mass by utilizing the 2-step tracking needed for common-mode noise rejection purposes. The trajectory of the spacecraft will be determined using standard methods of radiometric tracking, while the motion of the test mass relative to the spacecraft will be established by laser ranging technology. The test mass is at an environmentally quiet distance from the craft, ≥ 250 m. With occasional maneuvers to maintain formation, the concept establishes a flexible craft to test mass formation.
View Image Figure 7.1:
Results of Markwardt’s analysis [194] show Doppler residuals as a function of time of the best fit model. The top panel shows the residuals after setting a = 0 P, and demonstrates the linear increase with time. The top panel shows all of the data, including segments that were filtered out because of interference due to the solar corona (designated by a horizontal bar with “C”) or due to general noise (designated “N”). The bottom panel shows the filtered residuals, including the best fit value of the anomalous acceleration. The equivalent spacecraft velocity is also shown.
View Image Figure 7.2:
Results of Toth’s analysis [377]: a) best-fit residuals for Pioneer 10; b) best-fit residuals for Pioneer 10 with no anomalous acceleration term; c–d) same as a–b, for Pioneer 11.
View Image Figure 7.3:
Best-fit Pioneer 10 residuals using the ODYSSEY orbit determination program [179]. Left: residuals after a best-fit constant acceleration of − 10 2 aP = (8.40 ± 0.01) × 10 m ∕s. Right: reconstruction of the anomalous acceleration contribution.
View Image Figure 7.4:
The four possible different directions for the Pioneer anomaly: (1) toward the Sun, (2) toward the Earth, (3) along the velocity vector, and (4) along the spin axis. These directions would offer different signal modulations [260391] that could be detected in the new study.
View Image Figure 7.5:
Proposed directions (along the spin and antenna axes) from the Pioneer F spacecraft (to become Pioneer 10) toward the Earth [337].
View Image Figure 7.6:
The earlier part of the Pioneer 10 trajectory before Jupiter encounter, the part of the trajectory when antenna articulation was largest [337].
View Image Figure 7.7:
A geometric model (left) of the Pioneer spacecraft, used for finite element analysis, and a photograph (right) of Pioneer 10 prior to launch. The geometric model accurately incorporates details such as the Medium Gain Antenna (MGA), the Asteroid-Meteoroid Detector, and the star sensor shade. Note that in the geometric model, the RTGs are shown in the extended position; in the photograph, the RTGs are stowed. From [171172].
View Image Figure 7.8:
A “work-in-progress” temperature map of the outer surface of the Pioneer 10 spacecraft body, comparing temperatures calculated via a numerical finite element method vs. temperatures measured by platform temperature (PLT) sensors and telemetered. While agreement between calculated and telemetered temperatures is expected to improve as the model is being developed, discrepancies between these values illustrate the difficulties of creating a reliable temperature map using numerical methods. (From [171172]).
View Image Figure 7.9:
Heat generated by RTGs (red, approximately straight line, scale on left) and electrical equipment (green, scale on right) in Pioneer 10 over the lifetime of the spacecraft.
View Image Figure A.1:
Side view (above) and top view (below) of the high gain antenna, spacecraft body, and one RTG, with the boom length not to scale. Approximate measurements are in centimeters. For more accurate dimensions of the RTGs, consult Figure 2.5.
View Image Figure B.1:
Orbit Data Files.
View Image Figure C.1:
Sample Master Data Record.