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Mizera, P. F.

Publications and source records attributed to Mizera, P. F..

12 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1986

A multiple-satellite observation of the high-latitude auroral activity on January 11, 1983

Akasofu and Tsurutani (1984) have observed very unusual auroral activity on January 10-11, 1983. They employed visible line scan imagery from the Defense Meteorological Satellite Program (DMSP) F6 satellite to monitor auroral activity over the northern (winter) polar region. Magnetometer data from the ISEE 3 and IMP 8 spacecraft were used to monitor the interplanetary magnetic field (IMF) orientation. A number of auroral features which occurred in coincidence with changes in the IMF orientation were noted. The present paper is mainly concerned with the specific occurrence of a broad transpolar are later on January 11, 1983. During this occurrence, the IMF B(z) and B(y) components were positive and stable in time. This report has the objective to use a fortunate orbital configuration of three low-altitude polar orbiting spacecraft to probe the distribution of precipitating plasma responsible for the arc.

Gorney, D. J.↗
NASA NTRS1985

Aerospace spacecraft-charging guidelines document

A short summary document on spacecraft charging was prepared for use by engineers in the various Aerospace Corporation program offices that support Air Force Space Division programs. The magnetospheric charging environment at near-geosynchronous altitudes is outlined and the mechanisms of charging and discharging are discussed. Statistical results from the P78-2 (SCATHA) satellite engineering experiments are given. The document is intended to be a layman's source for charging information and for design guidance and criteria.

Fennell, J. F.↗
NASA NTRS1981

First results of material charging in the space environment

A satellite experiment, designed to measure potential charging of typical thermal control materials at near geosynchronous altitude, was flown as part of the SCATHA program. Direct observations of charging of typical satellite materials in a natural charging event ( 5 keV) are presented. The results show some features which differ significantly from previous laboratory simulations of the environment.

Stevens, N. J.↗
NASA NTRS1980

Electron angular distributions during charging events

The angular distribution of electrons and ions at times of spacecraft charging were examined for several charging events. Generally it was found that electrons measured perpendicular to the Earth's magnetic field are more intense and more energetic than those measured parallel to the magnetic field during charging events. During the substorm charging injection, the electron spectra harden at all angles to the magnetic field as the evolution of the charging spectra is monitored by the P78-2 satellites. An example of the onset of charging and the changes in the electron distributions is examined. The evolution of the electrons from a 'soft' plasma sheet distribution to a 'hard' charging distribution is compared with the charging of Kapton on the satellite and the spacecraft frame potential. The ions are used to determine the spacecraft potential. Evidence of periodic surface potential variations related to particle anisotropies are presented and discussed.

Fennell, J. F.↗
NASA NTRS1980

satellite surface potential survey

Results of Kapton differential voltage charging of the satellite surface potential monitor Kapton samples are presented for the first 100 days of P78-2 operations. Daily charging occurrences are plotted in magnetic local time and L-shell (altitude and magnetic latitude) space as a function of magnetic activity. Most of the low level charging occurs well into the dawn local time sector whereas the highest voltage levels occur in the premidnight local time sector. The probabilities of differential charging are extremely dependent on the local time sector, the altitude (or L-shell) and of course, the magnetic activity.

Mizera, P. F.↗
NASA NTRS1980

Three-dimensional analysis of charging events on days 87 and 114, 1979, from SCATHA

Angular distributions of ions and electrons from the Spacecraft Charging at High Altitudes (SCATHA) were investigated for the floating potential and the differential charging of the spacecraft as deduced from Liouville's theorem. The following was found: (1) short time charging events on the spacecraft are associated with short time increases of the intensity of 10 keV to 1 MeV electrons; (2) short time changes of the spacecraft differential potential are associated with simultaneous short time changes of the spacecraft floating potential; (3) solar UV intensities in penumbra anticorrelate with the spacecraft floating potentials; (4) NASCAP predicts correct forms of sunshade asymmetric surface potentials; (5) certain enhancements of the intensity of energetic ions diminishes the absolute value of the spacecraft surface potential; (6) spacecraft discharging events in times shorter than 20 sec did not change in the spectrum of the energetic plasma; (7) partial discharging of the spacecraft occurred upon entry into a magnetically depleted region; and (8) steady state potentials and transient potentials of duration less than 30 seconds are simulated by the NASCAP code.

Saflekos, N. A.↗
NASA NTRS1980

First results of material charging in the space environment

A satellite experiment, designed to measure potential charging of typical thermal-control materials at near-geosynchronous altitude, was flown as part of the Spacecraft Charging at High Altitudes program. Direct observations of charging of typical satellite materials in a natural charging event (greater than or equal to 5 keV) are presented. The results show some features which differ significantly from previous laboratory simulations of the environment.

Mizera, P. F.↗
NASA NTRS1980

Studies of auroral X-ray imaging from high altitude spacecraft

Results of a study of techniques for imaging the aurora from a high altitude satellite at X-ray wavelengths are summarized. The X-ray observations allow the straightforward derivation of the primary auroral X-ray spectrum and can be made at all local times, day and night. Five candidate imaging systems are identified: X-ray telescope, multiple pinhole camera, coded aperture, rastered collimator, and imaging collimator. Examples of each are specified, subject to common weight and size limits which allow them to be intercompared. The imaging ability of each system is tested using a wide variety of sample spectra which are based on previous satellite observations. The study shows that the pinhole camera and coded aperture are both good auroral imaging systems. The two collimated detectors are significantly less sensitive. The X-ray telescope provides better image quality than the other systems in almost all cases, but a limitation to energies below about 4 keV prevents this system from providing the spectra data essential to deriving electron spectra, energy input to the atmosphere, and atmospheric densities and conductivities. The orbit selection requires a tradeoff between spatial resolution and duty cycle.

Mckenzie, D. L.↗
NASA NTRS1980

Initial comparison of SSPM ground test results and flight data to NASCAP simulations

The satellite surface potential monitor (SSPM) has been developed for the P78-2 SCATHA (Spacecraft Charging At The High Altitudes) satellite to determine the response of selected spacecraft materials to charged-particle environmental fluxes. Since the monitor infers total surface voltages from a single point on the interior side of insulators, a ground simulation program was undertaken to develop analytical techniques to model the monitors and to obtain an experimental calibration of the relationship between the flight measurement techniques and actual measurements. The experimental testing was conducted using monoenergetic electron beams irradiating samples in the dark. An analytical computer model was developed in the NASCAP (NASA Charging Analyzer Program) code. The analytical model material properties for Kapton that controlled backscatter and secondary yield were adjusted to obtain a single set of values that produced reasonable fits for both voltages and currents. The analytical techniques developed in the ground technology investigation have been applied to space flight conditions. Predictions were compared with limited flight data. The agreement is very good indicating that the technique, and NASCAP, can be used to predict spacecraft material charging behavior. Details of the testing, the analytical modelling technique and flight data comparisons are presented.

Stevens, N. J.↗
NASA NTRS1979

Design, development, and flight of a spacecraft charging sounding rocket payload

Results of the flight of the spacecraft charging sounding rocket payload are given. The payload was designed to create charging by the emission of both positive ions and electrons. The relationship between environmental parameters and changes in vehicle potential during periods of emission was also studied.

Cohen, H. A.↗
NASA NTRS1979

Description and charging results from the RSPM

Representative satellite materials, to be flown on STP-78-2 in 1979 on the SSPM instruments, were included as part of the AFGL Rocket payload flown from White Sands Missile Range on January 21, 1978. Potentials as high as + 1100 volts on the conductor and + or - 400 volts on the insulator were recorded by the RSPM near the minimum in the electron density vs altitude profile. In addition to the charging potentials measured during ion gun operation, sample charging currents also were recorded with time resolutions near 30 milliseconds. These results demonstrate the validity of the experiment concept of the SSPM on SCATHA.

Mizera, P. F.↗