Guidance and C ontrol for the H igh S peed F light Demonstration P hase II

The High -Speed Flight Demonstration Phas e II is a flight experiment program to investigate the transonic aerodynamic characteristics of a winged re -entry vehicle. A vehicle based on a scaled HOPE -X configuration is lifted by a stratospheric balloon to an altitude of 20 -30 km, is released and acc elerates to transonic speed in free -fall. To acquire useful aerodynamic data, the guidance and control system must maintain vehicle's Mach number at a constant value while varying its angle of attack quasi -statically. After data acquisition is completed, t he vehicle must be guided to an appropriate recovery point and attain suitable recovery parameters. The G&C system was designed and evaluated based on simulation analysis, and performed satisfactorily in flight, meeting all specified design requirements . Nomenclature ay = sideway acceleration az = normal acceleration CD = drag coefficient CL = lift coefficient m C � = stability derivative