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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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On Feb. 15, 1992 the HITEN spacecraft was inserted into orbit about the Moon. HITEN was launched on 24 January 1990, by Japan's Institute for Space and Astronautic Science (ISAS) and traversed the Earth's geotail region survived two aerobraking passes in the Earth's atmosphere (March 1991), and visited the regions near the Earth-Moon.
This paper describes the JPL discovery of an integrated trajectory, and the tracking and orbit determination suuport provided by JPL's Deep Space Network and Multimission Navigation Team in support of the final targeting for lunar insertion.
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Hybrid quantum mechanical/molecular mechanical (QM/MM) methods allow simulations of chemical reactions in atomistic solvent and heterogeneous environments such as proteins. Herein, the nuclear–electronic orbital (NEO) QM/MM approach is introduced to enable the quantization of specified nuclei, typically protons, in the QM region using a method such as NEO-density functional theory (NEO-DFT). This approach includes proton delocalization, polarization, anharmonicity, and zero-point energy in geometry optimizations and dynamics. Expressions for the energies and analytical gradients associated with the NEO-QM/MM method, as well as the previously developed polarizable continuum model (NEO-PCM), are provided. Geometry optimizations of small organic molecules hydrogen bonded to water in either dielectric continuum solvent or explicit atomistic solvent illustrate that aqueous solvation can strengthen hydrogen-bonding interactions for the systems studied, as indicated by shorter intermolecular distances at the hydrogen-bond interface. We then performed a real-time direct dynamics simulation of a phenol molecule in explicit water using the NEO-QM/MM method. Furthermore, these developments and initial examples provide the foundation for future studies of nuclear–electronic quantum dynamics in complex chemical and biological environments.
Biological experiments and effects on two primates to determine versatility of design of orbiting primate spacecraft
Linear parameter combinations for lunar orbit determination
System analysis to determine orbital parameters influence on mission scientific objectives under engineering constraints, using value function
Orbital imagery for planetary exploration - radar, visual, ultraviolet, infrared and passive microwave imaging systems
Contingency procedures for lunar orbit and transearth injection in lunar mission
Time optimal rendezvous maneuver between neighboring elliptic orbits, discussing propulsive jet system with variable thrust
Periodic orbits in highly perturbed dynamical systems, studying characteristic curves of various families in galactic-type potential
System analysis to determine orbital parameters influence on mission scientific objectives under engineering constraints, using value function
Wind tunnel tests of downwash aerodynamic surface incidence angles on Saturn S-1C booster coupled to Grumman C-4 orbiter shuttle
Safety requirements and guidelines are listed for the sortie module, upper stage vehicle, and space station for the earth orbit operations of the space shuttle program. The requirements and guidelines are for vehicle design, safety devices, warning devices, operational procedures, and residual hazards.
Current NASA planning envisions an ambitious Jupiter tour mission which will arrive at the planet in the year, 1984. The objectives of this mission are to broaden our knowledge of the outer solar system and in particular to extend our understanding of the physical processes at work in the Jupiter and Galilean satellite environment. To achieve these goals, precise spacecraft navigation is a fundamental requirement inasmuch as very near encounters with the satellites are necessary both for the planned scientific investigations and to reduce fuel requirements necessary for orbital insertion about the planet. This paper, deals with problems of producing precise spacecraft state estimates relative to the Galilean satellites, with the aid of both earth-based radio and on-board video data.
The results of the analysis conducted on the telemetry data from the prelaunch, launch, and flight activation phases of LANDSAT-2 spacecraft are presented according to subsystems and interrelationships that exist between subsystems. Subsystem characteristics are included along with the flight evaluation results. Flight data are compared to baseline data established at the 20 C plateau during thermal vacuum testing of the spacecraft. Evaluation guidelines are derived from the specifications developed from the LANDSAT program objectives: (1) acquisition of multispectral images of the surface of the earth; and (2) use of the LANDSAT-2 receiving, frequency translating, and transmitting equipment as a relay system to gather data from fixed earth-based sensor platforms which are operated by individual investigators. Data are presented on the first 50 orbits of the spacecraft.