Options for a nondedicated mission to test the Pioneer anomaly

TL;DR

This paper explores how existing or planned space missions could be adapted to test the Pioneer anomaly, aiming to verify its existence and nature without dedicated missions.

Contribution

It proposes two feasible mission concepts that can verify the Pioneer anomaly and distinguish between different theoretical explanations.

Findings

Both mission concepts can verify the anomaly within 10% accuracy.

The concepts can differentiate between a central force, signal blueshift, and drag-like force.

System and trajectory modifications do not compromise primary mission objectives.

Abstract

The Doppler-tracking data of the Pioneer 10 and 11 spacecraft show an unmodelled constant acceleration in the direction of the inner Solar System. Serious efforts have been undertaken to find a conventional explanation for this effect, all without success at the time of writing. Hence the effect, commonly dubbed the Pioneer anomaly, is attracting considerable attention. Unfortunately, no other space mission has reached the long-term navigation accuracy to yield an independent test of the effect. To fill this gap we discuss strategies for an experimental verification of the anomaly via an upcoming space mission. Emphasis is put on two plausible scenarios: nondedicated concepts employing either a planetary exploration mission to the outer Solar System or a piggybacked micro-spacecraft to be launched from a mother spacecraft travelling to Saturn or Jupiter. The study analyses the impact of a Pioneer anomaly test on the system and trajectory design for these two paradigms. It is found that both paradigms are capable of verifying the Pioneer anomaly and determine its magnitude at 10% level. Moreover the concepts can discriminate between the most plausible classes of models of the anomaly, a central force, a blueshift of the radio signal and a drag-like force. The necessary adaptions of the system and mission design do not impair the planetary exploration goals of the missions.