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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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Plants in low gravity environment simulated by 2 rpm clinostat with horizontal axis, studying growth direction and respiratory metabolism
Prolonged recording from single vestibular units in frog during plane and space flight, significance and technique
Nonrotating, hydrostatic models of geochemically likely planets calculated using solar elemental abundances and equations of state for cold materials
Liquid sloshing at simulated low gravity in rigid cylindrical tank, noting analytical model and experimental results
Solar oblateness and Mercury perihelion advance, showing turbulent viscosity forces acting on photospheric meridional currents as possible distortion cause
Similarity parameters of gravity and pressure driven liquid discharge from propellant tanks obtained by dimensional analysis
Atmosphere of Mars studied using three models generated to show high, mean and low density compositions to account for gravitational and magnetic fields
Visual and gravitational factors in delay in perception of oculogravic illusion
Electron capture effects on gravitationally contracting iron stars of 1.4 and 2 solar masses
Gravitational torque effects and analysis for satellite design
Density wave theory and spiral gravitational field effects in migrating stars orbits and origins in Milky Way spiral arm, using Schmidt model
Lunar gravitational field effect on sun-earth exterior libration point location, examining placement on line passing through sun and earth-moon barycenter
Computer photokymographic recording of gravitational-inertial force environment effects on cardiovascular and respiratory systems on centrifuge
Simultaneous end-expiratory pressures, referred to midthoracic level, in the superior and abdominal venae cavae, pericardial space, and right and left heart, were recorded without thoracotomy in three anesthetized dogs during sudden changes from supine to vertical head-up or head-down body positions. Intrathoracic and dependent great vein pressures referred to midchest level (sixth thoracic vertebra) decreased and showed simple hydrostatic gradients in either vertical position. However, a discontinuity in the large vein hydrostatic gradient occurred just distal to the superior margin of the thorax in either body position and was resumed again above this level. It is concluded that, just as the cerebrospinal fluid and intraperitoneal pressures minimize the effects of gravitational and inertial forces on the cerebral and visceral circulations, the pericardial and pleural pressures have a similar role for the heart proper.
The problem was investigated of estimating the masses of Phobos and Deimos from Doppler and onboard optical measurements during the Viking extended mission. A Kalman filter was used to analyze the effects of gravitational uncertainties and nongravitational accelerations. These accelerations destroy the dynamical integrity of the orbit, and multibatch or limited memory filtering is preferred to single batch processing. Optical tracking is essential to improve the relative orbit geometry. The masses can be determined to about 10% and 25% respectively for Phobos and Deimos, assuming satellite densities of about 3 gr/cu cm.
Results of a sensitivity study on the proposed Lo-Lo (Twinsat) satellite-to-satellite tracking mission are described. The relative range-rate signal due to a local gravitational anomaly is investigated as a function of height and satellite separation. It is shown that the signal strength is weak and that an optimal combination of signal strength and resolution is achieved when the satellites are separated by 3 deg along-track. The signal does not resolve point masses closer than 5 deg apart when the satellites are at 300 km altitude. The influence of other factors on the system is evaluated, including the low frequency gravitation field effect on the orbit and the dependence of the noise of the data type on (electronic) integration time.
Experimental studies using a pulsed LED, Cerenkov source, and a 100 ps laser were made of various photomultipliers and discriminator combinations. In addition, a new type of neodymium-YAG frequency doubled laser was used as the basis for the development of a stable, short pulse, high repetition rate laser system. This laser was then used in conjunction with atomic clocks to study the effect of gravitational potential on elapsed time. Avenues to promote the development of international cooperation in the area of lunar laser ranging were also explored.
Barometric pressure, gas composition, toxicity, and thermal exchange of spacecraft cabin atmospheres are discussed. Effects of gravitation, acceleration, weightlessness, noise, and vibration on human behavior and performance during space flight are also described.