const EM = (mu  = 0.01215, Rp  = 6371E3, Rs  = 1.737E6, r12 = 384403e3, m1  = 5.972e24)
const SE = (mu  = 0.01215, Rp  = 6371E3, Rs  = 1.737E6, r12 = 384403e3, m1  = 5.972e24)
# When a system is added the function "createSystem(sys::System,G=6.673e-11::Float64)"
# has to be updated and a new struct created
