1–20 von 20 Ergebnissen
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    Improving the numerical integration solution of satellite orbits in the presence of solar radiation pressure using modified back differences

    Lundberg, J. B. / Feulner, M. R. / Abusali, P. A. M. et al. | NTRS | 1991
    that the method of modified back differences can be implemented with only a small increase in execution time. ...

    Manned space flight - The effects of Shuttle perturbations on orbital trajectory

    Barrett, Charles P. / Propst, Carolyn A. | NTRS | 1991
    maneuvers. While a portion of these changes are due to dynamical mismodeling, the majority of the changes are due to dynamics that are unique to the ...

    Application of partial differential equation modeling of the control/structural dynamics of flexible spacecraft

    Taylor, Lawrence W., Jr. / Rajiyah, H. | NTRS | 1991
    Partial differential equations for modeling the structural dynamics and control systems of flexible spacecraft are applied here in order to ...

    Precise tracking of the Magellan and Pioneer Venus orbiters by same-beam interferometry

    Border, James S. / Folkner, William M. / Kahn, Robert D. et al. | NTRS | 1991
    Results of a demonstration of same-beam interferometry, the simultaneous tracking of two spacecraft in orbit about a distant planet by ...

    An estimate of the global minimum DV needed for earth-moon transfer

    Sweetser, Theodore H. | NTRS | 1991
    ends in a 100 km altitude circular polar lunar orbit. The analysis used involves calculations of Jacobi's integral in a circular restricted ...

    A method for the construction of a lunar transfer trajectory using ballistic capture

    Miller, James K. / Belbruno, Edward A. | NTRS | 1991
    of propellant are shown over classical methods of orbit transfer such as the Hohmann transfer method. The savings in Delta V required of the ...

    EXCALIBIR - A space experiment in orbital debris lethality

    Culp, Robert D. / Dickey, Michael R. | NTRS | 1991
    by untrackable orbital debris, to provide lethality data to the kinetic energy weapons community, and to aid in the testing of space and ...

    Thermal imbalance force modelling for a GPS satellite using the finite element method

    Vigue, Yvonne / Schutz, Bob E. | NTRS | 1991
    the thermal imbalance force. Although this force may not be responsible for all of the force mismodeling, conditions may work in combination ...

    Determination and prediction of Magellan's orbit

    Engelhardt, D. B. / Mcnamee, J. B. / Wong, S. K. et al. | NTRS | 1991
    are given for the first 146 days of mapping (through February 8, 1991, 60 percent of the first rotation of Venus). Orbit accuracy requirements ...

    Field of view location and formation flying for polar orbiting missions

    Scolese, Christopher / Folta, David / Bordi, Francesco | NTRS | 1991
    The problem of flying an earth observing mission using a group of observatories flying in formation, rather than a single observatory, is ...

    Effect of heat rate constraint on minimum-fuel synergetic plane change

    Mease, Kenneth D. / Utashima, Masayoshi | NTRS | 1991
    approximately by parametrizing the controls and solving the resulting nonlinear programming problem. By considering several different levels of heat ...

    Motion requirements for antennas in geostationary earth orbit

    Tentor, Lawrence B. / Cudney, Harley H. / Werntz, Paul | NTRS | 1991
    Design dependencies of antennas in geostationary earth orbits are evaluated, and the tradeoffs between the optical geoscientific goals and ...

    A method for computing instantaneous downtrack error from TDRS Doppler residuals

    Haas, Franklin M., Jr. | NTRS | 1991
    A simple method has been developed which calculates the instantaneous downtrack error in an orbiting vehicle's state vector from TDRS ...

    Spacecraft-spacecraft very long baseline interferometry for planetary approach navigation

    Edwards, Charles D., Jr. / Folkner, William M. / Border, James S. et al. | NTRS | 1991
    factors of 2-3 improvement in spacecraft targeting over conventional Doppler, range, and quasar-relative VLBI, along with reduced sensitivity to ...

    Architecting a mission plan for Lunar Observer

    Ridenoure, Rex W. | NTRS | 1991
    The present status of NASA's Lunar Observer study effort at JPL is discussed in the context of an ongoing 20-year series of studies focused ...

    Autonomous precision landing using terrain-following navigation

    Vaughan, R. M. / Gaskell, R. W. / Halamek, P. et al. | NTRS | 1991
    Terrain-following navigation studies that have been done over the past two years in the navigation system section at JPL are described. A ...

    Autonomous Mars ascent and orbit rendezvous for earth return missions

    Edwards, H. C. / Balmanno, W. F. / Cruz, Manuel I. et al. | NTRS | 1991
    The details of tha assessment of autonomous Mars ascent and orbit rendezvous for earth return missions are presented. Analyses addressing ...

    Free return trajectories for Mars missions

    Wolf, Aron A. | NTRS | 1991
    for generating contours. Sample contours are presented for the trajectories and are used to show the variations in trajectory parameters found ...

    Optimal cycling between cislunar and cismartian libration points with reusable nuclear electric transfer vehicles

    Sponaugle, Steven J. / Rishikof, Brian H. / Davis, Steven F. et al. | NTRS | 1991
    A cyclical Mars exploration scenario is described which combines the use of libration points in the earth-moon and sun-Mars systems with a ...

    Mars approach navigation using Doppler and range measurements to surface beacons and orbiting spacecraft

    Thurman, Sam W. / Estefan, Jeffrey A. | NTRS | 1991
    approach velocity magnitudes; Doppler data in particular were found to perform poorly in determining the downtrack (along the direction of flight ...