Engineering topics

Flury, W.

Publications and source records attributed to Flury, W..

3 records

NASA NTRS1993

Orbital debris - Status and possibilities for control

The severity and significance for the future use of space of the continued deposition of orbital debris into the near-earth environment is examined, and approaches to controlling the growing orbital debris population are discussed. Three categories of options are considered: those requiring minimal impact on operations, those requiring changes in hardware or operations, and those requiring technology development. The necessary role of the international community is these efforts is emphasized.

Mcknight, D.↗

NASA NTRS1976

Lunar farside gravity - An assessment of satellite to satellite tracking techniques and gravity gradiometry

The estimation of local gravity anomalies represented by point masses using gravity gradiometer and satellite to satellite tracking data is discussed. A simulation analysis has been performed to study the recovery of local gravity anomalies from both rotating single axis gravity gradiometer and satellite to satellite tracking measurements. A Lunar Polar Orbiter mission concept is adopted for the orbits and data links. The sensitivity of the gravity determination to data noise, mass point spatial distribution (model errors), unmodelled gravity (gravity anomalies outside the area of interest), and orbit errors is studied. Figure of merit for the comparison is the rms error of radial acceleration.

Ananda, M.↗

NASA NTRS1975

Accurate integration of geostationary orbits with Burdet's focal elements

The theory of Burdet's focal elements (1969) is outlined. The differential equations are presented, and the initial value problem is described together with the transformation to rectangular coordinates and classical elements. The focal elements are well defined for zero eccentricity and inclination and can be adopted for the computation of elliptic, parabolic, and hyperbolic motion. For the numerical integration of near-geostationary orbits, a comparison of the efficiency is made between focal elements, Kustaanheimo-Stiefel (1971) theory, and rectangular coordinates. For this class of orbits, a higher accuracy has been obtained by integrating elements than integrating rectangular coordinates.

Flury, W.↗