Centauri Dreams is following the Pioneer 10 story with great interest, and not just in terms of the anomalous effects that continue to keep this mission in the news. Ponder that Pioneer 10 was launched in 1972 and consider that even with the technologies of its day, the probe may still be able to communicate with Earth. We have learned so much in the interim about hardened electronics and autonomous self-repair that there is reason to believe probes to even remoter locations in the Kuiper Belt and beyond are feasible providing we can solve the propulsion conundrum.

The next attempt to contact the venerable spacecraft would occur in March, if it occurs at all, and you can hear more about it in an interview conducted by Planetary Radio. The guest is JPL senior research scientist John Anderson, who discusses the mission, its current communications challenges, and the possible reasons for what appears to be its deceleration as it moves away from the Sun.

Or is the effect really a deceleration? A new paper called “Pioneer Anomaly: What Can We Learn from LISA?” has just appeared on the arXiv site, making the case that there is a second explanation: an anomalous blueshift of the radio signal. Authors Denis Defrère (University of Liege) and Andreas Rathke (Institute for Theoretical Physics, University of Cologne) examine the effects such a blueshift might have on the upcoming Laser Interferometer Space Antenna (LISA) mission to detect gravitational waves.

It would be useful if LISA could be used to verify the Pioneer data; it appears to be the earliest spacecraft that could make such an attempt. But the authors’ conclusion is discouraging: the anomalous blueshift is always overwhelmed by one or another noise source in the LISA interferometer.

And if LISA cannot test the Pioneer Anomaly, what can? From the paper:

More promising – and probably mandatory if the Pioneer anomaly represents a force and not a blueshift – would be a test in the outer Solar system by radio-tracking of a deep space vehicle with very well known onboard systematics. Preferably this would be a dedicated mission to explore the anomaly although a planetary exploration spacecraft which has been designed with the secondary goal to test the Pioneer anomaly could already gain considerable insights. The analysis of the full archive of Pioneer 10 and 11 Doppler data, that is currently being initiated, might further help to identify mission scenarios that are especially suited for a test of the anomaly.

It’s too late for New Horizons, of course, but any followup Pluto/Kuiper Belt mission would have such an opportunity. On that score, see T. Bondo, R. Walker, A. Rathke et al., “Preliminary Design of an Advanced Mission to Pluto,” scheduled to appear in the proceedings of the 24th International Symposium on Space Technology and Science, Miyazaki, Japan, June 2004, and already available online (PDF warning).