Talk detail

Participant	Modenini, Dario
Institution	University of Bologna - Via Fontanelle 40 - Forlì - - Italy

Session	SG1	Accepted	Yes	Order	3	Time	14:50
Talk	Oral abstract	Title	Pioneer 10 & 11 trajectories show no discrepancy with Newton-Einstein’s laws of gravity
Co-authors	Paolo Tortora
Abstract	We discuss orbital solutions for Pioneer 10 and 11 spacecraft obtained using extended Doppler data sets covering several years of interplanetary cruises. The data processing was carried out using NASA/JPL’s Orbit Determination Program (ODP) available at the University of Bologna thanks to a NASA/ASI bilateral agreement. Satisfactory orbital solutions are obtained when adding an ad-hoc developed model for estimating the thermal dissipation force as a source of non-gravitational acceleration affecting spacecraft dynamics, without the need for other accelerations of unknown origin to be solved-for. The development of the spacecraft thermal model, its integration into the ODP and the several orbital solutions obtained will be presented. All results lead to the conclusion that the trajectories followed by Pioneer probes are fully compatible with Newton-Einstein gravity law, as long as all non-gravitational accelerations are correctly accounted for.