Search NASA⌕ Search

Engineering topics

Miller, M. L.

Publications and source records attributed to Miller, M. L..

10 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1991

Mineralogy of an unusual Cr-rich inclusion in the Los Martinez (L6) chrondritic breccia

During the petrological study of the L6 chondritic breccia, Los Martinez, we discovered a large, highly unusual Cr-rich inclusion whose mineralogy appears to be unique in both terrestrial and extraterrestrial occurrences. We carried out electron microprobe, scanning electron microscopy, and transmission electron microscopy investigations of this inclusion in order to determine its composition and mineralogy in detail and to establish its origin and possible relationship to other Cr-rich objects in chondritic meteorites. Details of the chemical composition, origin, and thermal history are given.

Brearley, Adrian J.↗
NASA NTRS1989

Search for auroral belt E-parallel fields with high-velocity barium ion injections

In April 1984, four high-velocity shaped-charge Ba(+) injections were conducted from two sounding rockets at 770-975 km over northern Alaska under conditions of active auroral and magnetic disturbance. Spatial ionization (brightness) profiles of high-velocity Ba(+) clouds from photometric scans following each release were found to be consistent with the 28-sec theoretical time constant for Ba photoionization determined by Carlsten (1975). These observations therefore revealed no evidence of anomalous fast ionization predicted by the Alfven critical velocity hypothesis.

Heppner, J. P.↗
NASA NTRS1982

Thermospheric winds at high latitudes from chemical release observations

The considered investigation takes into account wind measurements conducted with the aid of 39 sounding rocket chemical release payloads. Attention is given to the geomagnetic dependence, winds and ion convection patterns, subauroral dayside measurements, evening auroral belt measurements, evening polar cap measurements, postmidnight polar cap measurements, midnight and early morning auroral belt measurements, late evening auroral belt measurements, and anomalous winds. The prevailing theme in presenting and interpreting the wind measurements between 160 and 320 km has been that the gross characteristics of the high-latitude wind system can be readily understood in terms of the pattern distribution of electric fields when the inertial properties of the neutral atmosphere and Coriolis forces are taken into account.

Heppner, J. P.↗
NASA NTRS1981

The CAMEO barium release - E/parallel/ fields over the polar cap

Four successive thermite barium releases at an altitude of 965 km over polar cap invariant latitudes 84 to 76 deg near magnetic midnight were conducted from the orbiting second stage of the vehicle that launched Nimbus 7; the releases were made as part of the CAMEO (Chemically Active Material Ejected in Orbit) program. This was the first opportunity to observe the behavior of conventional barium release when conducted at orbital velocity in the near-earth magnetic field. The principal unexpected characteristic in the release dynamics was the high, 1.4 to 2.6 km/s, initial Ba(+) expansion velocity relative to an expected velocity of 0.9 km/s. Attention is also given to neutral cloud expansion, initial ion cloud expansion, convective motion, and the characteristics of field-aligned motion. The possibility of measuring parallel electric fields over the polar cap by observing perturbations in the motion of the visible ions is assessed.

Heppner, J. P.↗