The dish antenna would be pointed towards the sun. The RTG would then be perpendicular to the spacecraft sun axis. This same configuration applies to the Ulysses and Voyager spacecraft. If the impact of "heat" from the sun and the re-radiation of said "heat", plus heat generated from the radioisotopic generator, are the source of this thrust, then wouldn't all of it would be imbalanced, some coming at greater leverage and from larger areas than others, imparting an uncontrolled, erratic yaw on the vehicle?
If the impact of "heat" from the sun and the re-radiation of said "heat", plus heat generated from the radioisotopic generator, are the source of this thrust, then wouldn't all of it would be imbalanced, some coming at greater leverage and from larger areas than others, imparting an uncontrolled, erratic yaw on the vehicle? They are spin stabilized, so no, I don't think that yaw would occur until the control systems run out of fuel.