The Pioneer anomaly: seeking an explanation in newly recovered data

Abstract

The Pioneer 10 and 11 spacecraft yielded very accurate navigation in deep space that was, however, limited by a small, anomalous frequency drift of their carrier signals received by the radio-tracking stations of the NASA Deep Space Network (DSN). This drift signifies a discrepancy between the frequency of the Doppler signals observed by the DSN and that frequency modeled using modern-day deep space navigational codes. This discrepancy, evident in the data for both spacecraft, was interpreted as an approximately constant acceleration. This acceleration has become known as the Pioneer anomaly. The origin of this anomaly is yet unknown. Recent efforts to explain the effect included a search for independent confirmation, analyses of conventional mechanisms, even ideas rooted in new physics, and proposals for a dedicated mission. We assert that to determine the origin of the Pioneer anomaly, and especially before any discussion of new physics and (or) a dedicated mission can take place, one must analyze the entire set of radiometric Doppler data received from Pioneer 10 and 11. In this paper, we report on our efforts to recover and utilize the complete set of radio Doppler and telemetry records of the Pioneer 10 and 11 spacecraft. The collection of radio Doppler data for both missions is now complete; we are ready to begin its evaluation. We also make progress utilizing the recently recovered Pioneer telemetry data in the development of a complete engineering profile of the spacecraft. We present a strategy for studying the effect of on-board-generated small forces with this newly recovered information on the performance of thermal, electrical, power, communication, and other subsystems, in conjunction with the analysis of the entire set of the Pioneer Doppler data. We report on the preparations for the upcoming analysis of the newly recovered data with the ultimate goal of determining the origin of the Pioneer anomaly. Finally, we discuss implications of our ongoing research of the Pioneer anomaly for other missions, most notably for New Horizons, NASA's recently launched mission to Pluto. PACS Nos.: 95.10.Ce, 95.10.Eg, 95.30.Sf, 95.55.Pe Résumé : Les sondes spatiales Pioneer 10/11 ont fourni des données très précises de navigation dans l'espace qui étaient, cependant, limitées par un petit déplacement anomal de fréquence de leurs ondes porteuses détectées par le Réseau Spatial de la NASA (DSN). Ce déplacement de fréquence signifie un déaccord entre la fréquence des signaux Doppler détectés par le DSN et les calculs de cette fréquence à l'aide des modèles informatisés les plus à jour pour les voyages spatiaux. Cette difference apparaît sur les signaux des deux sondes et a été interprétée comme correspondant à une accélération constante. Cette

Kinematical Conformal Cosmology: Fundamental Parameters from Astrophysical Observations

“…Moreover, the signal analysis performed so far [23,26] indicates an almost constant value of the anomalous acceleration or frequency shift reported above (temporal and space variation of a P within 10%), over a range of heliocentric distances ∼20-70 AU, and possibly at even closer distances 10 AU. The Pioneer phenomenology corresponds exactly to the simplest experiment we might conceive to check the validity of our model.…”

“…However, experimental evidence has recently accumulated regarding a possible local region of blueshift, related to the so-called Pioneer anomaly [21][22][23][24][25][26][27][28][29][30][31]. This is a small anomalous frequency drift, actually a blueshift, which was observed analyzing the navigational data from the Pioneer 10/11 spacecraft, received from distances between 20 and 70 astronomical units from the sun, while exploring the outer solar system.…”

“…These discoveries have prompted an extended reanalysis of all the historical navigational data from these space missions, which is currently underway [25][26][27][28]32], in order to determine additional characteristics of the anomaly, such as its precise direction, the possible temporal evolution, and its dependence on heliocentric distance. Future-dedicated missions are also being planned [33][34][35] to test directly this puzzling phenomenon.…”

Gravitational anomalies in the solar system?

“…In view of the lingering inability of finding satisfactory explanations to the PA in terms of both standard and unconventional physics over the years, a comprehensive new investigation of the anomalous behavior of the two probes was launched since mid of 2006 after the recovery of the much-extended set of radio-metric Doppler data for both spacecraft in conjunction with the newly available complete record of their telemetry files and a large archive of original project documentation. [229][230][231][232] The fruits of such hard and heroic efforts were not long in coming. Indeed, by analyzing the new data, conviction that suitably designed thermal models could likely explain the PA 219,[232][233][234][235][236][237][238][239] began to make its way.…”

Extended phase space thermodynamics and P–V criticality: Brans–Dicke–Born–Infeld vs. Einstein–Born–Infeld-dilaton black holes

“…(2) and (36)], one finds that although both Lagrangians lead to the Maxwell-dilaton Lagrangian for the weak nonlinearity strength (β → ∞), only the new Lagrangian [Eq. (36)] is the correct and consistent one with a conformal transformation.…”