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LWS-SET RELATED
PUBLICATIONS
SPACECRAFT CHARGING
Frederickson, A.R.
and Brautigam, D.H., Mining CRRES IDM Pulse Data and CRRES
Environmental Data to Improve Spacecraft Charging/Discharging
Models and Guidelines,
NASA/CR-2004-213228, George C. Marshall Space Flight
Center , Marshall Space Flight Center, AL 35812, National
Aeronautics and Space Administration, Washington, DC
20546-0001, June, 2004, pp. 53
Keywords: pulse data, charging, discharging, high energy, electrons,
electric field, internal discharge monitor, crres
Abstract: One can truly predict the charging and pulsing in space over a
year’s time using only the physics that worked for periods of
an hour and less in prior publications. All portions of the
task were achieved, including the optional portion of
determining a value for conductivity that best fit the data.
Fortran statements were developed that are required for the
NUMIT runs to work with this kind of data from space. In
addition to developing the Fortran for NUMIT, simple
correlations between the IDM pulsing history and the space
radiation were observed because we now have a better
characterization of the space radiation. The study showed
that: (1) the new methods for measurement of charge storage
and conduction in insulators provide the correct values to use
for prediction of charging and pulsing in space; (2) the
methods in NUMIT that worked well for time durations less than
hours now work well for durations of months; (3) an average
spectrum such as AE8 is probably not a good guide for
predicting pulsing in space—one must take time dependence into
account in order to understand insulator pulsing; and (4) the
old method for predicting pulse rates in space that was based
on the CRRES data could be improved to include dependencies on
material parameters.
Rantanen, R. and Gordon, T., ElectroStatic Return of Contaminants,
NASA/CR-2003-212637, George C.
Marshall Space Flight Center , Marshall Space Flight Center,
AL 35812, National Aeronautics and Space Administration,
Washington, DC 20546-0001, August, 2003, pp. 60
Keywords: electrostatic,
contaminants, molecules, ionized, charged surfaces,
sputtering, energy, cross sections, electrons
Abstract: A model has been
developed capable of calculating the electrostatic return of
spacecraft emitted molecules that are ionized and attracted
back to the spacecraft by the spacecraft electric potential
on its surfaces. The return of ionized contaminant
molecules to charged spacecraft surfaces is very important
to all altitudes. It is especially important at
geosynchronous and interplanetary environments since it may
be the only mechanism by which contaminants can degrade a
surface. This model is applicable to all altitudes and
spacecraft geometries. In addition, results of the model
will be completed to cover a wide range of potential space
systems.
Davis, V.A., Mandell, M.J., and Thomsen,
M.F., Characterization of Magnetospheric Spacecraft Charging
Environments Using the LANL Magnetosperic Plasma Analyzer
Data Set,
NASA/CR-2003-212745,
George C. Marshall Space Flight
Center , Marshall Space Flight Center, AL 35812, National
Aeronautics and Space Administration, Washington, DC
20546-0001, October, 2003, pp. 111
Keywords: plasma,
charging, ions, electrons, flux, density, chassis, energy,
Maxwellian, potential
Abstract: An
improved specification of the plasma environment has been
developed for use in modeling spacecraft charging. It was
developed by statistically analyzing a large part of the
LANL Magnetospheric Plasma Analyzer (MPA) data set for ion
and electron spectral signature correlation with spacecraft
charging, including anisotropies. The objective is to
identify a relatively simple characterization of the full
particle distributions that yield an accurate prediction of
the observed charging under a wide variety of conditions.
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