Abstract: Based on the norminal trajectory of aeroassisted orbital transfer,the paper gives a new navigation scheme for the space vehicle:Nayigation hardware/Equations of Motion(EM),GPS/EM,INS/EM are studied for the vehicle to determine the navigation information during aeroassisted orbital transfer.High supersonic aerodynamic calculation formulasare introduced to deduce the equations of filter and observation for the hybrid navigation system.The numerical results show that the navigation precision of GPS(or INS)/EM are much higher than that of single EM.GPS,or INS.The GPS(or INS)/EM has more redundance thlan the GPS(or INS).