I think it is an interesting paper. First, it derives from basic principles equations of the thermal recoil force. This is not usually in heat transfer textbooks, as those are more concerned about energy exchange than about momentum. We also derive the infamous factor of 2/3 for a Lambertian (diffuse) surface.
More notably, we make a direct connection between the thermal power of heat sources and the recoil force. The thermal power of heat sources within a spacecraft is usually known very well, and may also be telemetered. So, if a simple formalism exists that gives the recoil force as a function of thermal power, we have a very meaningful way to connect telemetry and trajectory analysis. This is indeed what my “homebrew” orbit determination code does, using Pioneer telemetry and Doppler data together.
No results yet… the paper uses simulated Pioneer 10 data, precisely to avoid jumping to a premature conclusion. We can jump to conclusions once we’re done analyzing all the data using methods that include what’s in this paper… until then, we have to keep an open mind.