Will any of this research help with the 'Pioneer Effect' problem?

Joined: 9 Feb 05
Posts: 29
Credit: 761,523
RAC: 0
Topic 192720

Will any of this research help with the 'Pioneer Effect' problem?


The effect is seen in radio Doppler and ranging data, yielding information on the velocity and distance of the spacecraft.

When all known forces acting on the spacecraft are taken into consideration, a very small but unexplained force remains. It causes a constant sunward acceleration of (8.74 ± 1.33) × 10−10 m/s2 for both spacecraft.

Data from the Galileo and Ulysses spacecraft indicate a similar effect, although for various reasons (such as their relative proximity to the Sun) firm conclusions cannot be drawn from these sources.

These spacecraft are all partially or fully spin-stabilised; the effect is harder to measure accurately with three-axis stabilised craft such as the Voyagers.

The effect is so small that it could be a statistical anomaly caused by differences in the way data was collected over the lifetime of the probes.

Numerous changes were made over this period, including changes in the receiving instruments, reception sites, data recording systems and recording formats.

The Pioneer Explorer Collaboration is expecting to address this concern around June 2007. They are currently re-outputting all of the Pioneer data from the spacecraft's entire recorded flight time into a single common format.

Using this data it should be possible to determine if the acceleration is directed Earthward, suggesting data collection artifacts, or Sunward, suggesting a real effect that requires explanation.