  The design of an invariant tracking control law for the kinematic car driving
on a sphere is discussed. Using a Lie group framework a left-invariant
description on SO(3) is derived. Basic geometric considerations allow a direct
comparison of the model with the usual planar case. Exploiting the Lie group
structure an invariant tracking error is defined and a feedback is designed.
Finally, one possible design of an invariant asymptotic observer is sketched.
