HR: 1330h
AN: SH42A-0501    [PDF]
TI: Specifying the ISS Plasma Environment
AU: * Minow, J
EM: joseph.minow@msfc.nasa.gov
AF: Jacobs Sverdrup, MSFC Group, MSFC/ED44, Huntsville, AL 35812 United States
AU: Diekmann, A
EM: anne.diekmann@msfc.nasa.gov
AF: Jacobs Sverdrup, MSFC Group, MSFC/ED44, Huntsville, AL 35812 United States
AU: Neergaard, L
EM: linda.neergaard@msfc.nasa.gov
AF: Jacobs Sverdrup, MSFC Group, MSFC/ED44, Huntsville, AL 35812 United States
AU: Bui, T
EM: them.bui@msfc.nasa.gov
AF: Microcraft, MSFC Group, MSFC/ED44, Huntsville, AL 35812 United States
AU: Mikatarian, R
EM: ronald.r.mikatarian@boeing.com
AF: The Boeing Company, Mail Code HB3-20, 13100 Space Center Blvd., Houston, TX 77509 United States
AU: Barsamian, H
EM: hagop.r.barsamian@boeing.com
AF: The Boeing Company, Mail Code HB3-20, 13100 Space Center Blvd., Houston, TX 77509 United States
AU: Koontz, S
EM: steven.l.koontz@nasa.gov
AF: NASA, Johnson Space Center, JSC/ES4, Houston, TX 77058 United States
AB: Quantifying the spacecraft charging risks and corresponding hazards for the International Space Station (ISS) requires a plasma environment specification describing the natural variability of ionospheric temperature (Te) and density (Ne). Empirical ionospheric specification and forecast models such as the International Reference Ionosphere (IRI) model typically only provide estimates of long term (seasonal) mean Te and Ne values for the low Earth orbit environment. Knowledge of the Te and Ne variability as well as the likelihood of extreme deviations from the mean values are required to estimate both the magnitude and frequency of occurrence of potentially hazardous spacecraft charging environments for a given ISS construction stage and flight configuration. This paper describes a statistical analysis of historical ionospheric low Earth orbit plasma measurements used to estimate Ne, Te variability in the ISS flight environment. The statistical variability analysis of Ne and Te enables calculation of the expected frequency of occurrence of any particular values of Ne and Te, especially those that correspond to possibly hazardous spacecraft charging environments. The database used in the original analysis included measurements from the AE-C, AE-D, and DE-2 satellites and recent work on the database has added additional satellites to the database and ground based incoherent scatter radar observations as well. Deviations of the data values from the IRI estimated Ne, Te parameters for each data point provide a statistical basis for modeling the deviations of the plasma environment from the IRI model output.
DE: 7853 Spacecraft/atmosphere interactions
DE: 7855 Spacecraft sheaths, wakes, charging
SC: SPA - Solar and Heliospheric Physics [SH]
MN: 2003 Fall Meeting