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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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Orbit determination of the Lunar Prospector spacecraft performed at the Jet Propulsion Laboratory was conducted as part of the lunar gravity experiment.
An experimental system, called GPS-like tracking, was used to track TDRS and GPS satellites simultaneously from a small (3 station) ground network. Comparison with the operational precise orbit indicates that GLT determined the TDRS orbit to within 25 m.
This paper presents an algorithm to autonomously determine the orbit of a spacecraft around a small solar system object (such as an asteroid) using a wide field-of-view camera and a precomputed model of the object.
Results of orbit determination for the TOPEX/Poseidon(T/P)mission using Global Positioning Satellites(GPS)during Anti-Spoofing (A-S) activities are presented in this paper.
The trajectory of the Ulysses spacecraft carries it over the South polar region of the Sun in mid-1994, albeit at a great distance from the Sun itself. During this time the South Solar latitude of Ulysses' orbit reaches a maximum value of 80.2 degrees, and the geocentric declination reaches a magnitude of over 75 degrees. As a result, a number of unique and interesting events occur, not the least of which being that Ulysses never sets over the Canberra tracking station of the DSN for more than two months. A less obvious aspect of the Sun-spacecraft-Earth geometry during this time is the return of solar-induced nutation to the spin-stabilized Ulysses spacecraft, and the consequent use of active nutation control. Both of these events have significant implications for theory and practice of Ulysses' orbit determination during this period, which is the subject of the proposed paper.
The NASA James Webb Space Telescope (JWST) mission successfully launched on December 25, 2021, at 12:20 UTC. This paper details several novel challenges encountered in the orbit determination (OD) of JWST during the launch and early orbit. The first OD solution used only 6.5 hours of tracking data, much less than the 24 hours of data usually required for libration orbiters on an outbound trajectory. In addition, the observatory area exposed to solar radiation pressure changed through a series of sunshield deployments while concurrent momentum unloads and attitude telemetry outages occurred. This paper covers how the Flight Dynamics Team (FDT) prepared for these challenges, how these challenges were handled on-orbit, and the performance of the resulting OD solutions.
The NASA James Webb Space Telescope (JWST) mission successfully launched on December 25, 2021, at 12:20 UTC. This paper details several novel challenges encountered in the orbit determination (OD) of JWST during the launch and early orbit. The first OD solution used only 6.5 hours of tracking data, much less than the 24 hours of data usually required for libration orbiters on an outbound trajectory. In addition, the observatory area exposed to solar radiation pressure changed through a series of sunshield deployments while concurrent momentum unloads and attitude telemetry outages occurred. This paper covers how the Flight Dynamics Team (FDT) prepared for these challenges, how these challenges were handled on-orbit, and the performance of the resulting OD solutions.
Determination of the solar parallax with microwave absorption line techniques
Proton-proton spin decoupling method for the determination of nuclear magnetic chemical shifts
Determination of rare-earth elemental abundances in meteorites
Instrumentation design for experiment to determine absolute electron densities in ionosphere
Determination of the emissivity of materials
Determination and survey of periodic trojan orbits in the restricted problem of three bodies
Determination of radiation configuration factors
Spectrophotometric determination of microgram quantities of water
Determination of pressure vessel strengths as influenced by notches of various radii
Sodium vapor pressure determination
Composition determination of microgram quantities of oxides of platinum