CartesianOrbit.getE() returns NaN on hyperbolic orbits
The getE() method is declared for all orbit types and should always
return a meaningful value.
Cartesian orbits should support hyperbolic orbits.
The getE() implementation only supports elliptic orbits and returns NaN when used on hyperbolic orbits
(from redmine: issue id 336, created on 2017-05-03, closed on 2017-07-27)