Obliquity evolution of the minor satellites of Pluto and Charon

•A damped mass-spring model within an N-body simulation is to study spin and obliquity evolution of spinning non-round bodies in circumbinary orbit to study obliquity evolution of Pluto and Charon’s minor satellites.•A tidally evolving Styx exhibits intermittent obliquity variations and episodes of tumbling.•During a previous epoch where Charon migrated away from Pluto, the minor satellites could have been trapped in orbital mean motion inclination resonances and associated spin resonances. An outward migrating Charon induces large variations in Nix and Styx’s obliquities.•As the minor satellites are near mean motion resonances, this mechanism could have lifted the obliquities of all four minor satellites.•The high obliquities need not be primordial if the minor satellites were at one time captured into mean motion resonances.