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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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At least 109 records · Page 6
All sourcesNASA NTRSDOE OSTI
NASA NTRS2021

New Tools for Tour Design: Swiss Cheese Plot, Invariant Funnel, and Resonant Encounter Map

We define a new set of tools for tour design introduced in previous work: the”Swiss Cheese Plot,” ”Invariant Funnel,” and ”Resonant Encounter Map.” These tools promise to be useful in designing, analyzing, and navigating low-energy trajectories through multi-body systems. We review and clarify methods for generating the swiss cheese plot and invariant funnels in the Circular Restricted Three-Body Problem. We introduce the resonant encounter map as a graphical representation of the three-body design space, similar to the pork-chop plot for the two-body problem. We also discuss some interesting characteristics of the resonant encounter map and its connection to the invariant manifolds of periodic libration orbit

Close, Sigrid↗
NASA NTRS2003

Cassini tour navigation strategy

The Cassini-Huygens spacecraft was launched on October 15, 1997 as a joint NASA/ESA mission to explore Saturn. After a 7 year cruise the spacecraft will enter orbit around Saturn on 1 July 2004 for a 4 year investigation of the Saturnian system. The Cassini Navigation Team is responsible for designing the reference trajectory and conducting operations to realize this design. This paper describes the strategy for achieving project requirements, the characteristics of the Cassini navigation challenge, and the underlying assumptions.

Saturn↗
NASA NTRS1972

Definition phase study of the grand tour missions

The research to define an energetic particle experiment for the OPTGT-MJS missions is reported. The studies reported include: (1) the use of silicon dectectors for low energy, low flux level measurements in the presence of RTG radiation and trapped electrons, (2) high energy proton damage of lithium-drifted and surface barrier silicon detectors, (3) the gas Cerenkov counter, (4) systems for detection of trapped high-energy protons in the presence of trapped electrons, and (5) reliability and redundancy.

Simpson, J. A.↗
NASA NTRS1972

Outer planet Grand Tour missions photometry/polarimetry experiment critical components study

Work performed during this effort was limited to two primary areas of technical concern: optical design optimization, and sensor selection. An optical system concept was established, and various system components were evaluated through experimental test sequences. Photodetectors were investigated for the applicability in meeting OPGT requirements as constrained by the photometry/polarimetry team directives. The most promising (gallium arsenide PMT) was further experimentally tested to ascertain its behavior with respect to anticipated environmental conditions. Results of testing and summary of the preceding tradeoff study effort are presented.

Pellicori, S. F.↗
NASA NTRS1972

Power source considerations for Grand Tour missions.

At the present time, there exists no known power source that will satisfy the power, weight, lifetime, and other stringent requirements of an extended outer-planet mission. Exploratory studies indicate the need for a solar-independent power source capable of supplying approximately 500 W of power over mission lifetimes of up to 12 years. The only known power source which can possibly meet these requirements, in the 1975 to 1979 time period, is a radioisotope thermoelectric generator (RTG). In 1969 a program began to develop a long-life, plutonium-fueled radioisotope thermoelectric power system. Aspects of spacecraft configuration are discussed together with power source requirements, RTG/spacecraft integration, operational details, and problems of safety.

Merrill, O. S.↗
NASA NTRS1972

Definition phase of Grand Tour missions/radio science investigations study for outer planets missions

Scientific instrumentation for satellite communication and radio tracking systems in the outer planet exploration mission is discussed. Mission planning considers observations of planetary and satellite-masses, -atmospheres, -magnetic fields, -surfaces, -gravitational fields, solar wind composition, planetary radio emissions, and tests of general relativity in time delay and ray bending experiments.

Tyler, G. L.↗
NASA NTRS1974

Outer planets Grand Tour ultraviolet spectroscopy experiment

The principal objective is presented of the UV observations, with emphasis placed on hydrogen and helium. Calculations are given for airglow and occultation. Mission requirements and trajectories are also reported for future observations.

Donahue, T. M.↗
NASA NTRS1973

The Jupiter orbiter satellite tour mission

Consideration of the problem of exploring the Jupiter-Galilean satellite system by a spacecraft in orbit about the planet. A simple patched conic algorithm is developed which identifies Jupiter orbiter trajectories that utilize gravity assist flybys of the Galilean satellites. A detailed reference mission is designed against specific science criteria for satellite exploration to demonstrate the possible science return of utilizing close satellite encounters. A navigation strategy is developed, including both planet and satellite relative orbit determination and a maneuver analysis; spacecraft delivery statistics are determined in the barycentric Jupiter-Galilean satellite coordinate system and mapped to the satellite target planes to determine feasibility. A simple maneuver sequence is employed which yields acceptable velocity requirements.

Beckman, J. C.↗
NASA NTRS1989

Jupiter - First stop on Voyager's grand tour

The findings concerning Jupiter that were made by the Voyager missions are briefly reviewed. The ring and three new moons around Jupiter, the live volcanoes on Io, and atmospheric phenomena on Jupiter which were observed by Voyager 1 are described. The discoveries regarding Callisto and Europa made by Voyager 2 are briefly summarized.

Morrison, David↗
NASA NTRS1990

Object-oriented requirements analysis: A quick tour

Of all the approaches to software development, an object-oriented approach appears to be both the most beneficial and the most popular. The description of the object-oriented approach is presented in the form of the view graphs.

Berard, Edward V.↗
NASA NTRS1993

The grandest tour - Voyager

The Voyager mission based on two spacecraft, Voyager 1 and Voyager 2, launched on September 5, 1977 and August 20 1977, respectively, is reviewed. The mission was designed to take advantage of a rare geometric arrangement of Jupiter, Saturn, Uranus, and Neptune that occurs only once every 176 years. Particular attention is given to data on Jupiter's ring and moons, the discovery of active volcanoes on Io, Jovian magnetism, Saturn's atmosphere, Titan and other moons, Uranus and Miranda, Uranian moons and rings, Triton's atmosphere.

Murrill, Mary B.↗