Search for a Standard Explanation of the Pioneer Anomaly

The data from Pioneer 10 and 11 shows an anomalous, constant, Doppler frequency drift that can be interpreted as an acceleration directed towards the Sun of aP = (8.74 ± 1.33) × 10-8 cm / s 2. Although one can consider a new physical origin for the anomaly, one must first investigate the contributions of the prime candidates, which are systematics generated on board. Here we expand upon previous analyses of thermal systematics. We demonstrate that thermal models put forth so far are not supported by the analyzed data. Possible ways to further investigate the nature of the anomaly are proposed.