Friday, May 5, 2006
The Pioneer Anomaly:
New Data and New Investigation
NASA Jet Propulsion Laboratory
The Pioneer 10/11 spacecraft yielded the most precise navigation in deep space to date. However, their radiometric tracking data received from the distances between 20-70 astronomical units from the Sun has consistently indicated the presence of a small, anomalous, Doppler frequency drift. The drift is a blue shift, uniformly changing with a rate of ~6 x 10-9 Hz/s and can be interpreted as a constant sunward acceleration of each particular spacecraft of aP = (8.74 ± 1.33) x10-8 cm/s2 . This signal has become known as the Pioneer anomaly; the nature of this anomaly remains unexplained. We will discuss the details of this recent investigation focusing on effects both external to and internal to the spacecraft, as well as those due to modeling and computational techniques. We will summarize our current knowledge of the conditions led to observation of the anomalous acceleration on the Pioneer spacecraft. We review some of the mechanisms proposed to explain the anomaly and show their inability to account for the magnitude and observed behavior of the discovered anomaly. We discuss the current state of the efforts to retrieve the entire data sets of the Pioneer 10 and 11 radiometric Doppler data. We also report on the availability of recently recovered telemetry files that may be used to reconstruct the engineering history of both spacecraft using original project documentation and newly developed software tools. We discuss possible ways to further investigate the discovered effect using these telemetry files in conjunction with the analysis of the much extended Pioneer Doppler data and will emphasize the significance of the new analysis for understanding the Pioneer anomaly.
Refreshments at 4:00 PM. Seminar begins at 4:10 PM.
Building 8 (Science Bldg.) - Room 241
For further information, please call (909) 869-4014