Engineering topics

Brown, J. W.

Publications and source records attributed to Brown, J. W..

25 records · Page 2

NASA NTRS1976

Shuttle remote manipulator system workstation - Man-machine engineering

A major subsystem aboard the Shuttle Orbiter, the Remote Manipulator System (RMS) provides the capability to deploy and retrieve free-flying satellites, support attached payload operations, and aid in crewmember rescue from a disabled vehicle should the requirement arise. The Remote Manipulator System consists of 15.3-m (50 ft) articulated booms, end effectors, operator workstation, and closed circuit video, power and control subsystems. The manipulator booms (or arms) and end effectors are located in the Orbiter payload bay and operated from inside the cabin by one crewmember. This paper is primarily concerned with the design and development of the RMS operator's workstation, the man-machine engineering features and interfaces, and man-in-the-loop simulations and testing results obtained to date by the National Aeronautics and Space Administration (NASA).

Brown, J. W.↗

NASA NTRS1974

Reduced gravity fecal collector seat and urinal

A waste collection system for use in a reduced gravity including a seat having an opening centrally located with a pair of opposed depressed valleys on opposite sides of said opening for accommodating the ischial tuberosities of a user. The seat has contoured surfaces for providing support of the user's body and includes a prominent ridge towards the rear, which provides forward-aft positioning cue to the user. A curved recess is provided adjacent the forward portion of the seat for accommodating a tubular urinal having an enlarged open mouth.

Brown, J. W.↗

NASA NTRS1974

Measurements of the cosmic-ray Be/B ratio and the age of cosmic rays

The ratio Be/B depends on whether the confinement time of cosmic rays in the Galaxy is long or short compared to the radioactive half-life of Be-10. We report observations of this ratio which were obtained with a dE/dx-Cerenkov detector launched into a polar orbit on OGO-6 as part of the Caltech Solar and Galactic Cosmic Ray Experiment. Be/B ratios were determined for various rigidity thresholds up to 15 GV. We find no statistically significant rigidity dependence of the ratio, which is 0.41 plus or minus 0.02 when averaged over all observed cutoffs. Additional calculations suggest that if the present fragmentation parameters are correct, then the lifetime of cosmic rays in the Galaxy is less then 10 m.y.

Brown, J. W.↗

NASA NTRS1974

The elemental abundance ratios of interstellar secondary and primary cosmic rays

We report new observations of abundances in the charge range (Z) between 2 and 10, which were obtained with a dE/dx-Cerenkov detector launched into a polar orbit on OGO-6 as part of the Caltech Solar and Galactic Cosmic Ray Experiment. Integral rigidity spectra of all the elements observed have shapes similar to that of the helium spectrum in the rigidity range of 2 to 14 GV, approaching a power law with exponent -1.6 above 8 GV. Calculations of interstellar propagation assuming a steady-state model and including the presence of interstellar helium and the effects of solar modulation predict a variation with rigidity of ratios such as Be-O and B/O, which is not observed. The data can be explained by assuming a rigidity-dependent confinement of cosmic rays within the Galaxy.

Brown, J. W.↗

NASA NTRS1973

A satellite measurement of cosmic-ray abundances and spectra in the charge range 2 less than or equal to 7 less than or equal to 10

The composition of the nuclear component of the cosmic radiation was studied to yield information concerning the source, propagation, and confinement of cosmic rays within the galaxy. The first comprehensive satellite measurement is presented of cosmic-ray composition and spectra in the charge range 2 equal to or less than Z equal to or less than 10 using the geomagnetic field as a rigidity analyzer through the entire range of vertical cutoffs. The results indicate that the spectra of all the elements in the observed range are similar, and thus that various ratios of elemental abundances are nearly independent of rigidity over the range 2 equal to or less than P equal to or less than 15 GV. Calculations of the propagation of cosmic rays through the interstellar and interplanetary media predict that there should be a variation with rigidity of ratios of various elements, because of the charge-dependent effects of ionization of the interstellar gas by the cosmic rays. The absence of this variation can be explained by assuming a rigidity-dependent confinement of the cosmic rays in the galaxy.

Brown, J. W.↗

NASA NTRS1972

High-energy electron spikes at high latitudes.

Observation of over 750 spikes of precipitating electrons with E greater than or equal to 425 keV aboard the low-altitude polar orbiter Ogo 4 between July 30 and Dec. 31, 1967. The spikes may be divided into three distinct populations, depending on whether they occur at latitudes below, at, or above the local limit of trapping. These spikes are designated type 1, 2, and 3, respectively. Type 3 spikes occur in a narrow latitude band about 3 deg wide, centered at invariant latitude Lambda approximately equal to 78 deg at 1000 MLT (magnetic local time) and 68 deg at 2000 MLT. Type 3 spikes appear to be associated with spikes observed near the magnetopause and the neutral sheet. Type 2 spikes also occur in a latitude band about 3 deg wide, centered at about 71 deg at 1000 MLT and 67 deg at 2200 MLG. Type 2 spikes appear to be related to island fluxes in the neutral sheet, although they occur on closed field lines and may persist for many hours. Type 1 spikes occur in a wider band of latitudes, from about 62 deg to 68 deg near midnight and 66 deg to 68 deg near noon. Although they are observed on closed field lines, type 1 spikes do not persist for periods longer than about 1 hour, and it is concluded that they are produced by strong pitch-angle scattering from the stably trapped population.

Brown, J. W.↗

NASA NTRS1972

High energy electron spikes at high latitudes

Over 750 spikes of precipitating electrons with E or = 425 KeV were observed aboard the low altitude polar orbiter OGO-D between 30 July 1967 and 31 December 1967. The spikes may be divided into three distinct populations, depending on whether they occur at latitudes below, at, or above the local limit of trapping.

Brown, J. W.↗