Theoretical studies of the solar wind phenomenon.
Solar wind phenomenon, discussing angular momentum loss to sun, fluctuations at earth orbit and wind conditions at terminus and regions unvisited by spacecraft
Parker, E. N.↗
SEARCH · Engineering Papers
Results for “Angular Momentum”
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.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Interplanetary gas. XVI.
Quiet solar wind model with magnetic field numerically calculated, obtaining coronal electron densities and angular momentum near earth
Brandt, J. C.↗
Conservation laws and Liapounov stability of the free rotation of a rigid body.
Conservation laws and Liapunov stability of free rotation of rigid body about principal axes derived from kinetic energy and angular momentum
Vinti, J. P.↗
Physical conditions in the primitive solar nebula.
Primitive solar nebula physical model considered under angular momentum conservation in collapsing fragment
Cameron, A. G. W.↗
Theory of phase transitions in solid hydrogen.
Order-disorder transitions in solid hydrogen, discussing model to explain molecular rotation angular momentum operator fluctuations
Flax, L.↗
Systems analysis research
Equations of lunar motion, measurement of solar angular momentum, probability of electricity propulsion system failure, and smoothing of sequentially correlated processes
Source record↗
Rotational properties of neutron star models
Rotational properties of neutron star models for Crab Nebula energy source, using expressions for angular momentum and rotational kinetic energy
Cameron, A. G. W.↗
General relativistic rotational properties of stellar models
General relativistic expressions for angular momentum and rotational kinetic energy of slowly rotating stars
Cohen, J. M.↗
Interplanetary gas. XV - Nonradial plasma motions from the orientations of ionic comet tails
Type I comet tails orientations dispersion attributed to nonradial plasma waves and discontinuities in interplanetary gas, calculating solar angular momentum loss rate
Brandt, J. C.↗
Nonlinear resonant attitude motions in gravity- stabilized gyrostat satellites
Gravity stabilized gyrostat satellites internal angular momentum effect on nonlinear resonant attitude motions
Crespo Da Silva, M. R. M.↗
Low-thrust, minimum-fuel, orbital transfers
Low thrust minimum fuel space vehicle transfer from initial circular orbit to coplanar elliptic orbit of given energy and angular momentum
Brusch, R. G.↗
Inelastic transition densities
Inelastic scattering transition densities in single particle operator reduced matrix elements between initial and final nuclear states for nucleon angular momentum calculations
Braley, R. C.↗
The rotating Einstein-Rosen bridge
Angular momentum of rotating Einstein-Rosen bridge, comparing neutron star models
Cohen, J. M.↗
Stellar and solar rotation
The angular momentum of stars and its distribution within the stars are discussed. Observed surface velocities dependent on a variety of factors are examined, including age, mass, spectral type, and binarism. The rotation and surface velocity of the sun are also considered.
Ostriker, J. P.↗
Effect of environmental torques on short-term attitude prediction for a rolling-wheel spacecraft in a sun-synchronous orbit
A numerical evaluation and an analysis of the effects of environmental disturbance torques on the attitude of a hexagonal cylinder rolling wheel spacecraft were performed. The resulting perturbations caused by five such torques were found to be very small and exhibited linearity such that linearized equations of motion yielded accurate results over short periods and the separate perturbations contributed by each torque were additive in the sense of superposition. Linearity of the torque perturbations was not affected by moderate system design changes and persisted for torque-to-angular momentum ratios up to 100 times the nominal expected value. As these conditions include many possible applications, similar linear behavior might be anticipated for other rolling-wheel spacecraft.
Hodge, W. F.↗
Attitude stability of spinning flexible spacecraft
The stability of spinning flexible satellites in a force-free environment was analyzed. The satellite was modeled as a rigid core having attached to it a flexible appendage idealized as a collection of particles (point masses) interconnected by springs. Both Liapunov and Routh-Hurwitz stability procedures are used. In the former, the Hamiltonian of the system, constrained through the angular momentum integral so as to admit complete damping, is used as a testing function. Equations of motion are written using the hybrid coordinate formulation, which readily accepts a modal coordinate transformation ultimately allowing truncation to a level amenable to literal stability analysis. Closed form stability criteria are generated for the first mode of a restricted appendage model lying in a plane containing the system center of mass and orthogonal to the spin axis. The effects of spin on flexible bodies are discussed by considering a very elementary particle model. Control of passively unstable spacecraft is briefly considered.
Likins, P. W.↗
D autoionization states of He and ionic H
Positions of the lowest 1,3De autoionization states of He and H(-) below the n = 2 level of the He(+) and H were calculated variationally, using Feshbach's Q-operator formalism. The trial wave function is of the Hylleraas-type with appropriate angular momentum factors. The widths and the shifts of the states have also been calculated. The shifts are found to be positive for all the states calculated here. The results with 112 terms for most states are lower than any previously calculated. The calculated lowest autoionization states of the He and H(-) (relative to the ground states of He and H respectively) are 59.902 eV and 10.1185 eV, in good agreement with the observed values of 59.9 eV and 10.13 + or 0.015 eV.
Bhatia, A. K.↗
Comparison of satellite theories
The accuracy of five mathematical models in computing a nominal orbit for the Vanguard 2 satellite by using a position velocity vector is considered. Either numerical integration or analytical theories are used in all models as well as the same force model that corresponds to a potential with the zonal harmonics to order four. The amounts of spread in the values of the total energy and the z-component of the angular momentum for a set of times are considered as measures of accuracy.
Hertz, H. G.↗