The X-33 Advanced Technology Demonstrator is a half-scale prototype developed to test the key technologies needed for a full-scale single-stage reusable launch vehicle (RLV). The X-33 is a suborbital vehicle that will be launched vertically, and land horizontally. The goals of this research were to develop an alternate entry guidance scheme for the X-33 in parallel to the actual X-33 entry guidance algorithms, provide comparative and complementary study, and identify potential new ways to improve entry guidance performance. Toward these goals, the nominal entry trajectory is defined by a piecewise linear drag-acceleration-versus-energy profile, which is in turn obtained by the solution of a semi-analytical parameter optimization problem. The closed-loop guidance is accomplished by tracking the nominal drag profile with primarily bank-angle modulation on-board. The bank-angle is commanded by a single full-envelope nonlinear trajectory control law. Near the end of the entry flight, the guidance logic is switched to heading control in order to meet strict conditions at the terminal area energy management interface. Two methods, one on ground-track control and the other on heading control, were proposed and examined for this phase of entry guidance where lateral control is emphasized. Trajectory dispersion studies were performed to evaluate the effectiveness of the entry guidance algorithms against a number of uncertainties including those in propulsion system, atmospheric properties, winds, aerodynamics, and propellant loading. Finally, a new trajectory-regulation method is introduced at the end as a promising precision entry guidance method. The guidance principle is very different and preliminary application in X-33 entry guidance simulation showed high precision that is difficult to achieve by existing methods.


    Access

    Access via TIB

    Check availability in my library


    Export, share and cite



    Title :

    Entry Guidance for the Reusable Launch Vehicle


    Contributors:
    Lu, Ping (author)

    Publication date :

    1999-01-01


    Type of media :

    Report


    Type of material :

    No indication


    Language :

    English







    Predictor-corrector entry guidance for reusable launch vehicles

    Chowdhry, Rajiv / Zimmermann, Curtis / Youssef, Hussein et al. | AIAA | 2001


    Entry Guidance and Trajectory Control for Reusable Launch Vehicles

    Lu, P. / American Institute of Aeronautics and Astronautics | British Library Conference Proceedings | 1996