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Results for “ORBITING SATELLITE”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1963

SATELLITE ORBITAL DATA

Satellite orbital data for explorer i, vii, viii, ix and vanguard ii and iii - orbital elements

EXPLORER VII SATELLITE↗
NASA NTRS1966

Satellite orbital data

Satellite orbital element tables derived from field reduced photographic observations

SATELLITE ORBIT↗
NASA NTRS1989

Sampling characteristics of satellite orbits

The irregular space-time sampling of any finite region by an orbiting satellite raises difficult questions as to which frequencies and wavenumbers can be determined and which will alias into others. Conventional sampling theorems must be extended to account for both irregular data distributions and observational noise - the sampling irregularity making the system much more susceptible to noise than in regularly sampled cases. The problem is formulated here in terms of least-squares and applied to spacecraft in 10-day and 17-day repeating orbits. The 'diamond-pattern' laid down spatially in such repeating orbits means that either repeat period adequately samples the spatial variables, but the slow overall temporal coverage in the 17-day pattern leads to much greater uncertainty than in the shorter repeat cycle. The result is not definitive and it is not concluded that a 10-day orbit repeat is the most appropriate one. A major conclusion, however, is that different orbital choices have potentially quite different sampling characteristics which need to be analyzed in terms of the spectral characteristics of the moving sea surface.

Wunsch, Carl↗
NASA NTRS1963

THE SPHEROIDAL METHOD FOR SATELLITE ORBITS

Artificial satellite orbit calculation of an oblate planet, by using approximation for planets gravitational potential which leads to spheroidal method

GRAVITATIONAL POTENTIAL↗
NASA NTRS1973

The tidal loss of satellite-orbiting objects and its implications for the lunar surface

The solar system is composed of numerous bodies orbiting the sun, and numerous satellites orbiting planets. However, no objects greater than a kilometer in diameter are known to orbit satellites. Theoretical arguments are used to show that most objects orbiting satellites ultimately would be destroyed by tidal interactions. This may explain why such objects have not been observed. These arguments are applied to objects orbiting the moon. The ages and sizes of most of the circular mare basins are compatible with the lifetimes and crater sizes expected for impacts by objects caught in decaying lunar orbits. The morphology of a few circular mare basins (Crisium, Serenitatis, and possibly Imbrium) indicates that they could have been formed by such impacts. Thus, the lunar surface may provide a record of impacts due to objects caught in tidally decaying lunar orbits.

Reid, M. J.↗
NASA NTRS1995

Relay Satellite Orbit Selection Considerations for Future Robotics Missions to Explore Venus

Discusses orbit design trades relevant to use of a Venus orbiting relay satellite supporting a variety of potential Venus robotic mission types. The emphasis is on the impact of mission tele- communications requirements on selection of a relay satellite orbit and its characteristics that can benefit or hinder mission performance for the potential robotic missions now under consideration.

Venus↗
NASA NTRS1989

Method of resolving radio phase ambiguity in satellite orbit determination

For satellite orbit determination, the most accurate observable available today is microwave radio phase, which can be differenced between observing stations and between satellites to cancel both transmitter- and receiver-related errors. For maximum accuracy, the integer cycle ambiguities of the doubly differenced observations must be resolved. To perform this ambiguity resolution, a bootstrapping strategy is proposed. This strategy requires the tracking stations to have a wide ranging progression of spacings. By conventional 'integrated Doppler' processing of the observations from the most widely spaced stations, the orbits are determined well enough to permit resolution of the ambiguities for the most closely spaced stations. The resolution of these ambiguities reduces the uncertainty of the orbit determination enough to enable ambiguity resolution for more widely spaced stations, which further reduces the orbital uncertainty. In a test of this strategy with six tracking stations, both the formal and the true errors of determining Global Positioning System satellite orbits were reduced by a factor of 2.

Councelman, Charles C., III↗
DOE OSTI2016

FROM ORDER TO CHAOS IN EARTH SATELLITE ORBITS

We consider Earth satellite orbits in the range of semimajor axes where the perturbing effects of Earth’s oblateness and lunisolar gravity are of comparable order. This range covers the medium-Earth orbits (MEO) of the Global Navigation Satellite Systems and the geosynchronous orbits (GEO) of the communication satellites. We recall a secular and quadrupolar model, based on the Milankovitch vector formulation of perturbation theory, which governs the long-term orbital evolution subject to the predominant gravitational interactions. We study the global dynamics of this two-and-a-half degrees-of-freedom Hamiltonian system by means of the fast Lyapunov indicator (FLI), used in a statistical sense. Specifically, we characterize the degree of chaoticity of the action space using angle-averaged normalized FLI maps, thereby overcoming the angle dependencies of the conventional stability maps. Emphasis is placed upon the phase-space structures near secular resonances, which are of primary importance to the space debris community. We confirm and quantify the transition from order to chaos in MEO, stemming from the critical inclinations and find that highly inclined GEO orbits are particularly unstable. Despite their reputed normality, Earth satellite orbits can possess an extraordinarily rich spectrum of dynamical behaviors and, from a mathematical perspective, have all the complications that make them very interesting candidates for testing the modern tools of chaos theory.

79 ASTRONOMY AND ASTROPHYSICS↗