UAH Archives, Special Collections, and Digital Initiatives

Browse Items (4 total)

  • spc_horn_000065_000085.pdf
  • spc_horn_000065_000085.pdf

    The summary notes, "In 1960, research work was begun to develop new guidance concepts for the Saturn space vehicles. [...] This paper presents the basics of the Iterative Guidance Law developed for Saturn launch vehicles to meet these new requirements of space age guidance. The development of the Iterative Guidance Law and the results and ideas presented in this paper are due primarily to Mr. Helmut J. Horn and his associates in the Dynamics Analysis and Flight Mechanics Division of the Aero-Astrodynamics Laboratory." Marked "Research Review, OK" in the upper right corner of the first page. The document includes corrections and additions to the text in red pencil.
  • spc_horn_000001_000064.pdf

    From the abstract: "This report discusses the iterative guidance mode and its application to three-dimensional upper stage vacuum flight. It is an inertial or closed system mode in that the only inputs required after liftoff are available from the onboard navigation system. That is, the iterative scheme computes steering commands as a function of the state and of the vehicle - velocity, position, longitudinal acceleration, and gravitational acceleration - and the desired cutoff conditions. The guidance commands are updated each guidance cycle, using the updated state of the vehicle. The iterative guidance scheme is a path adaptive guidance scheme in that it will retain its optimization properties under all expected types and magnitudes of vehicle perturbations without any loss in accuracy at liftoff."
  • spc_horn_000087.pdf

    From the summary: "Both [guidance] schemes steer toward a specified end point. The MIT scheme uses thrust to cancel out the effective gravity, a nonlinear term, which may be inefficient in certain cases. The MSFC scheme is more closely connected with calculus of variations and optimization theory in a reasonable degree of approximation."