SEARCH · Search NASA
Results for “Path”
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.
Prediction of the dynamic environment of spacecraft components. Part 2 - Acoustic and structural path transmission through two models of a shroud-enclosed spacecraft Final report
Acoustic and structural path transmission through shroud enclosed spacecraft
Classical path A and B functions for line broadening of positive ions
A, a and B functions for electron broadening of positive ions with hyperbolic path
Pulse operated flow path selector valve assembly Final test report
Operational test and evaluation of pulse operated flow path selector valve assembly
Measurements of electronic mean free paths in argon plasmas
Measurements of electronic free paths in argon discharge using interaction between plasma electrons and slow wave on helix
Classical path broadening functions for a Debye shielded interaction
Procedure to replace electron correlation effects with Debye shielded interaction including classical path broadening functions for Stark effects
Flight determined acceleration and climb performance of an F-104G airplane for use in an optimum flight path computer program
Computer program for optimum flight path defined by flight test investigation of performance characteristics /excess thrust, fuel flow, and climb potential/ of F-104G aircraft
Phase and amplitude scintillations of microwave signals over an elevated atmospheric path
Phase and amplitude scintillations of microwave signals over elevated atmospheric path for obtaining atmospheric density profiles
A search for residual magnetism along a tornado path
Statistical analysis of electrical phenomena associated with tornado activity and search for residual magnetism in buildings near path of tornado
Diversity performance of the wide-band FSK system in a three-component two-path channel
Wideband FSK system involving direct and reflected path transmission, predicting diversity performance from mathematical model
Effects of atmospheric path on airborne multispectral sensors
Atmospheric path effects on spectral radiance intensity in remote airborne multispectral sensors
Flight path optimization with multiple time scales
Flight path optimization with multiple time scales, discussing decoupling of high order three dimensional aircraft flight problem into several low order problems
Automated flight path design for planetary flyby missions using advanced interactive graphics hardware/software
Computer graphic interactive flight path design program for planetary flyby missions
Unified classical path theories of pressure broadening.
Derivation of a unified classical path theory of pressure broadening, using only elementary concepts. It is shown that the theory of Smith, Cooper and Vidal (1969) is only correct at all frequencies to first order in the number density of perturbers.
A band model formulation for very nonuniform paths.
Anomalous behavior has been observed when molecular band-models incorporating the Curtis-Godson or similar approximations are applied to problems characterized by a large variation in temperature along the optical path. The nature of this misbehavior has been examined and a procedure has been developed for its suppression by the introduction of a less restrictive assumption in the derivation of the band model from the basic equation of transfer.
Perturbation guidance for minimum time flight paths of spacecraft.
The problem of transferring a rocket vehicle from a given circular orbit to a larger coplanar circular orbit in minimum time, using a constant low-thrust rocket engine, is considered. Parameters are chosen to correspond to a transfer from the earth's orbit in heliocentric space to the orbit of Mars. A path satisfying the first order necessary conditions of variational calculus is shown to be locally minimizing by application of a set of second order conditions. A physical explanation is offered to justify the retrothrust period occurring during the flight. A neighboring optimum feedback control law, based on estimated time-to-go, is applied to this problem. State variable and terminal constraint feedback gains are calculated while one of the second order conditions, involving the backward integration of a matrix Riccati equation, is being tested.
Laser range measurement for a satellite navigation scheme and mid-range path selection and obstacle avoidance
The functions of a laser rangefinder on board an autonomous Martian roving vehicle are discussed. The functions are: (1) navigation by means of a passive satellite and (2) mid-range path selection and obstacle avoidance. The feasibility of using a laser to make the necessary range measurements is explored and a preliminary design is presented. The two uses of the rangefinder dictate widely different operating parameters making it impossible to use the same system for both functions.
Point and path performance of light aircraft: A review and analysis
The literature on methods for predicting the performance of light aircraft is reviewed. The methods discussed in the review extend from the classical instantaneous maximum or minimum technique to techniques for generating mathematically optimum flight paths. Classical point performance techniques are shown to be adequate in many cases but their accuracies are compromised by the need to use simple lift, drag, and thrust relations in order to get closed form solutions. Also the investigation of the effect of changes in weight, altitude, configuration, etc. involves many essentially repetitive calculations. Accordingly, computer programs are provided which can fit arbitrary drag polars and power curves with very high precision and which can then use the resulting fits to compute the performance under the assumption that the aircraft is not accelerating.