Data Set Overview : This dataset contains the Galileo spacecraft trajectory during the Earth-2 flyby. The data have been derived from SPICE kernels at a 1 minute sample rate. The data are provided in both Geocentric Solar Ecliptic (GSE) and Geocentric Solar Magnetic (GSM) coordinates and are given in units of earth radii (Re) where 1 Re : 6378 km. Data : ------------------------------------------------------------------ Table 1. Data record structure, ------------------------------------------------------------------ Column Units Description ------------------------------------------------------------------ time seconds S/C event time (UT) in the PDS format (yyyy-mm-ddThh:mm:ss.sss ) X Re S/C position X component in GSE or GSM coords. Y_gse Re S/C position Y component in GSE coords. Z_gse Re S/C position Z component in GSE coords. Y_gsm Re S/C position Y component in GSM coords. Z_gsm Re S/C position Z component in GSM coords. Coordinate Systems : The Galileo trajectory data are being archived in 2 coordinate systems. Geocentric Solar Ecliptic (GSE) and Geocentric Solar Magnetic (GSM) are related earth centered coordinate systems. Both the GSE and GSM X directions are taken along the Earth - Sun line, positive towards the Sun. The GSE Z direction is parallel to the ecliptic normal, positive northward, and Y completes the right-handed set (towards dusk). For GSM, the X-Z plane contains the Earth's dipole moment vector, positive northward, and Y completes the right-handed set. GSE coordinates are commonly used for analyzing the solar wind near the Earth and GSM coordinates are used when analyzing data inside the Earth's bow shock. Data Processing : The trajectory has been derived from the Galileo SPK kernel: 'S970311A.BSP' This kernel was obtained by the PDS-PPI node from the PDS-NAIF node. The code which produced the trajectory data was developed and executed at PDS-PPI. This code utilized SPICE routines which were developed at and distributed by PDS-NAIF. Both SPICE kernels and code may be available through PDS-NAIF.

Confidence Level Overview : The data have been derived from the Galileo SPICE kernels using well tested software from the SPICELIB and GLLSPICE subroutine libraries. Each data point is computed using S/C and planetary ephemerides computed at the time of the dataset sample (not interpolated).