Evaluation of potential changes to the Space Shuttle Orbiter's Flight Control System to increase directional control during post landing rollout
By: Linda J. Ham
Contributors: Naval Postgraduate School (U.S.) 
Publisher: Naval Postgraduate School; Available from National Technical Information Service
Published: 1997
Place of publication: Monterey, Calif; Springfield, Va
Language: eng
Number of pages: 113
Description: Space Shuttle Orbiter landings indicate both long term directional instability and the potential for pilot induced      oscillations during landing and rollout before nosewheel touchdown. The Orbiter's Flight Control System      requires improvements to increase directional control in the two points stance (after main gear touchdown with      the nose in the air). A number of modifications are proposed to improve directional control. This thesis      describes the control deficiency, potential improvements to the Flight Control System (FCS), and evaluates a      number of these improvements. The evaluation was performed by modeling the Orbiter's postlanding      lateral/directional control laws using a commercially available engineering software package known as      MATLAB 5.0. Directional control of the Orbiter was evaluated with and without the proposed modification to      obtain a comparison of control response. Initial evaluation of future Orbiter FCS modifications could be      performed using commercially available engineering software packages such as MATLAB; rather than costly      full-up Orbiter simulators. A low cost initial evaluation of changes may save NASA resources.
Notes: "September 1997."

Thesis advisor(s): Terrence W. Wilcutt, Richard M. Howard.

Thesis (M.S. in Astronautical Engineering) Naval Postgraduate School, September 1997.

Includes bibliographical references (p. 111)

Approved for public release; distribution unlimited.

Also available online.

Mode of access: World Wide Web.

System requirements: Adobe Acrobat reader.

NASA author.

dk/dk cc:9116 04/17/98.