Biophysical evaluation of the human vestibular system Semiannual status report
Analytical model of canalicular response to rotation in linear acceleration fields
Meiry, J. L.↗
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Biophysical evaluation of the human vestibular system Semiannual status report
Physical properties of labyrinthine fluids and semicircular canal response to angular and linear acceleration and thermal stimulation
Meiry, J. L.↗
Investigation of hypervelocity microparticles impact phenomena
Micrometeoroid linear accelerator for particle velocities up to 25 km/sec and thin film penetration studies
Roy, N. L.↗
Experimental studies of the eliciting mechanism of motion sickness
Linear acceleration movements as eliciting mechanism of motion sickness
Sjoeberg, A.↗
Cryogen acquisition in orbit
Orbital cryogen acquisition is a definite requirement for engine restart and/or propellant transfer on all major future missions. The most promising methods, especially for large scale vehicles, are acquisition by linear acceleration and acquisition by capillary systems. Intermittent acceleration and propellant settling requires some state-of-the-art extension since it has not been attempted on a large scale cryogen vehicle. Capillary acquisition systems offer the advantages of reusability, passiveness, low weight, and mission flexibility. The major disadvantage is that of an undeveloped technology. The method does not lend itself to verification through ground testing.
Hastings, L. J.↗
Experimental measurements of motion cue effects on STOL approach tasks
An experimental program to investigate the effects of motion cues on STOL approach is presented. The simulator used was the Six-Degrees-of-Freedom Motion Simulator (S.01) at Ames Research Center of NASA which has ?2.7 m travel longitudinally and laterally and ?2.5 m travel vertically. Three major experiments, characterized as tracking tasks, were conducted under fixed and moving base conditions: (1) A simulated IFR approach of the Augmentor Wing Jet STOL Research Aircraft (AWJSRA), (2) a simulated VFR task with the same aircraft, and (3) a single-axis task having only linear acceleration as the motion cue. Tracking performance was measured in terms of the variances of several motion variables, pilot vehicle describing functions, and pilot commentary.
Ringland, R. F.↗
Modulation of ring-laser mode coupling.
This paper develops an analytical, algebraic formalism that predicts effects induced in ring lasers by phase modulation, corresponding both to mode-decoupling mechanisms deliberately incorporated in the ring laser and to naturally occurring periodic or random angular or linear accelerations. The analysis is based on an approach that seems potentially convenient in the analysis of other systems that are physically stable but mathematically nonlinear.
Whitney, C.↗
Primary cosmic ray electrons above 10 GeV: Evidence for a spectral break
A balloon borne measurement of the cosmic ray electron spectrum from 10 to 200 GeV is reported in which two new techniques have been used to remove proton background contamination. First, the depth of the spectrometer was more than 25 radiation lengths, the equivalent of more than 2 mean free paths of material, enabling hadronically and electromagnetically induced cascades to be differentiated for a subset of the data. Second, electromagnetic cascade starting points were determined to within + or - 0.1 radiation lengths based upon a calibration with electrons from 5.4 to 18 GeV at the Stanford Linear Accelerator, greatly reducing the chances for a proton to simulate an electron. The resulting spectrum, when fitted with a power law, is quite steep, -3.2 + or - 0.1, but the chi-square fit is marginal. A significantly better fit is achieved assuming a transition region model in which the source spectral index is 2.7 with a break occurring at about 50 GeV.
Silverberg, R. F.↗
Cosmic ray electrons of E greater than 1 Gev - Some new measurements and interpretations.
In the summer of 1971 new measurements were made of the primary electron spectrum from 1 to 20 GeV with an electron spectrometer telescope at Fort Churchill. This telescope has been calibrated by using electrons and pions of 0.5 to 15 GeV at the Stanford Linear Accelerator in early 1971 and again in 1972. The calibration results suggest that the events observed are due to interactions of high-energy protons. The measured primary electron spectrum is uncomfortably close to that calculated for secondary electrons produced by the interaction of cosmic ray nuclei with interstellar hydrogen in the Galaxy, and therefore the question of the origin of the high-energy electrons is reopened. The problem of the age of cosmic ray electrons must also be reexamined if the measured spectrum is found to extend to still higher energies.
Webber, W. R.↗
Effects of aircraft design on STOL ride quality: A simulator study
To improve the ride quality in short takeoff aircraft, several means have been investigated. In general, these methods consist of placing sensors in the aircraft which sense aircraft motion, usually linear accelerations and angular rates. These signals are then used to deflect control surfaces which generate aerodynamic forces and moments which tend to minimize the motion which the passenger feels. One of the disadvantages of some of these systems is that they may tend to degrade the handling qualities or controllability of the airplane, making it more difficult or annoying for the pilot to fly. Rather than using active control systems to control ride quality, one might possibly design aircraft so that they are inherently pleasant to ride. The purpose of this study is to determine the relationship between characteristic aircraft motions and aircraft ride quality.
Jacobson, I. D.↗
Primary cosmic ray electrons above 10 GeV - Measurements using a thick detector
A balloon-borne measurement of the cosmic ray electron spectrum from 10 to 200 GeV is reported in which two new techniques have been used to remove proton background contamination. First, the depth of the spectrometer was more than 40 radiation lengths, the equivalent of more than 3 mean free paths of material, enabling hadronically and electromagnetically induced cascades to be differentiated for a subset of the data. Second, electromagnetic cascade starting points were determined to within plus or minus 0.1 radiation lengths on the basis of a calibration with electrons from 5.4 to 18 GeV at the Stanford Linear Accelerator, greatly reducing the chances for a proton to simulate an electron. The resulting spectrum, when fitted with a power law, is quite steep, -3.2 plus or minus 0.1, but the fit to a power law is marginal.
Silverberg, R. F.↗
The shape of the primary cosmic ray electron spectrum above 10 GeV
A balloon borne measurement of the cosmic ray electron spectrum above 10 GeV is reported in which two new techniques have been used to remove proton background contamination. First, the depth of the spectrometer on one of the flights was more than 40 radiation lengths, enabling hadronically and electromagnetically induced cascades to be differentiated for a subset of the data. Second, electromagnetic cascade starting points were determined to within about 0.1 radiation lengths based upon a calibration with electrons from 5.4 to 18 GeV at the Stanford Linear Accelerator. The resulting spectrum, when fitted with a power law, is steep, but the fit is marginal. A significantly better fit is achieved by assuming a model in which the spectrum is steepening in the measured region.
Silverberg, R. F.↗
Individual differences in susceptibility to motion sickness among six Skylab astronauts
Motion sickness was studied in Skylab crewmen. By mission-day 8 (MD 8), astronauts were virtually free of motion sickness symptoms after rotation and linear acceleration tests. None of the Skylab-II astronauts (crewmen 1-3) was motion sick aloft, but astronaut 6 of the Skylab-III crew experienced motion sickness within an hour after transition into orbit. All three astronauts (4-6) of Skylab-III experienced motion sickness in the workshop, where astronaut 6 was most susceptible and astronaut 4 least susceptible. The higher susceptibility of SL-III crewmen in the workshop, as compared with SL-II crewmen, may be attributable to the fact that they were based in the command module (CM) less than one-third as long as were SL-II astronauts. I.e., the unnatural movements permitted in the open spaces of the workshop entrained more complex interactions of unusual vestibular and visual stimuli than did those in the CM. The observed reduced liability to kinetosis relative to earth may be due to absence of the gravity stimulus to the otolith organs.
Graybiel, A.↗
Measurements of selected psi /3684/ branching ratios from a study of secondary lepton pairs
The measurements considered were made at the electron-positron storage ring at the Stanford Linear Accelerator Center. The apparatus used consists of two identical spectrometers mounted in a collinear configuration about the beam-interaction region. The energies of secondary electrons or positrons are measured with good resolution in large NaI(Tl) total-absorption detectors. Data accumulated without gamma-ray converters were examined for electron-positron pairs. The data taken with gamma-ray converters in place and at center-of-mass energies within 1 MeV of the resonance energy were scanned for evidence of either charged particles or converted gamma rays accompanying the detected muon pairs.
Hilger, E.↗
Aircraft motion and passenger comfort data from scheduled commercial airline flights
Data concerning the ride quality of aircraft taken on board commercial airline flights was presented. Five types of data are included: (1) root mean square (RMS) values of linear acceleration, angular acceleration or angular velocities, along with passenger subjective evaluations, (2) power spectra for the motion in each of six degrees of freedom, (3) scattergrams showing the probability density of the rms accelerations in the vertical and transverse directions, (4) probability distributions of the motion, and (5) on board noise levels during takeoff, climb, cruise, and descent.
Gruesbeck, M. G.↗
Equipment
A discussion is presented on the problems encountered in designing and constructing a simulator to determine human vestibular response to a range of linear accelerations from 0 to 0.3 g's. Starting with a set of initial performance specifications, the designers combined an array of commercially available components into a system which, altough requiring further refinement before completion, shows considerable promise of fulfilling the initial requirements. The resulting system consists of a wheeled vehicle driven by a cable and drum arrangement, powered by a hydraulic-electric servo-valve. Technical design considerations are presented along with a discussion of the trade-offs between various component options. A description of the system characteristics as well as an analysis of preliminary test results and recommendations for future system improvements are included.
Source record↗
Low-G fluid transfer technology study
Technology gaps and system characteristics critical to cryogenic and noncryogenic in-orbit fluid transfer were identified. Four different supply systems were conceptually designed as space shuttle payloads. These were; (1) space tug supply - LH2, LO2, N2H4, He - linear acceleration for liquid acquisition with supply module and tug separated from shuttle, (2) tug supply using orbiter drag, (3) orbiter supply - N2O4,MMH,He, H2,O2 - surface tension screens, (4) multiple receivers supply 0 solar electric propulsion stage, Hg, diaphragm - HEAO B, HEe, paddle fluid rotation-satellite control section, N2H4, screens. It was found that screens had the best overall potential for low weight and simplicity, however, thermal problems with cryogenics still need final resolution.
Stark, J. A.↗
The YF-12 Gust Velocity Measuring System
A true gust velocity measuring system designed to alleviate complications resulting from airframe flexibility and from the high-speed, high-temperature environment of supersonic cruise aircraft was evaluated on a YF-12 airplane. The system uses fixed vanes on which airflow direction changes produce differential pressure variations that are measured. Airframe motions, obtained by postflight integration of recorded angular rate and linear acceleration data, are removed from the flow angle data. An example of turbulence data obtained at high-altitude, supersonic flight conditions is presented and compared with previous high-altitude turbulence measurements obtained with subsonic aircraft and with turbulence criteria contained in both military and civil design specifications for supersonic cruise vehicles. Results of these comparisons indicate that the YF-12 turbulence sample is representative of turbulence present in the supersonic cruise environment.
Ehernberger, J.↗