A gas turbine engine system includes an electric starter motor which utilizes a partially hollow or cupped shaped rotor. Space is provided inside the rotor to fit the required clutch, bearings, and drive shaft. A rotor shaft drives the input shaft through the clutch. The clutch is mounted within a clutch cavity formed within an annular housing portion of the housing. The annular housing portion is at least partially conical and preferably extends at least partially within a hollow rotor mounted to the rotor shaft. A short package is provided due to the telescoped architecture while retaining the maximum length for electromagnetics.