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Availability: Archived at NSSDC, accessible from elsewhere

Time span: 1993-08-28 to 1993-08-28


This description was generated automatically using input from the Planetary Data System.

Data Set Overview ================= This dataset contains the Galileo spacecraft trajectory data sampled every minute for Aug. 28, 1993. The spacecraft closest approach to the asteroid was at 16:52:07 at a range of about 2410 km. The trajectory data are provided in two coordinate systems, Ida-centric Solar Ecliptic (IdaSE) and Heliographic (HG) coordinates. The position of the spacecraft has been extracted from the SPICE kernels provided by the project. The time tags are the exact times for which the S/C position was calculated. The time tag is spacecraft event time (SCET) given in universal time (UT). Primary Dataset Reference: Kivelson, M.G., Z. Wang, S. Joy, K.K. Khurana, C. Polanskey, D.J. Southwood, and R.J. Walker, 'Solar Wind Interactions with Small Bodies: 2. What Can Galileo's Detection of Magnetic Rotations Tell Us About GASPRA and IDA', Advances in Space Research, 1995. [KIVELSONETAL1995] Data ==== -----------------------------------------------------------------Table 1. Data record structure -----------------------------------------------------------------Column Description -----------------------------------------------------------------time S/C event time (UT) given in PDS time format YYYY-MM-DDThh:mm:ss.sssZ X S/C distance from Ida in the X-direction in IdaSE coordinates <km> Y S/C distance from Ida in the Y-direction in IdaSE coordinates <km> Z S/C distance from Ida in the Z-direction in IdaSE coordinates <km> R S/C radial distance from the sun <AU> LAT S/C solar latitude <degrees> LON S/C solar (east) longitude <degrees> Missing data values = 9999999.9 and 99999.999 Fortran Format of the data file: (1X, A24, 3F11.1,3F11.5) Coordinate Systems ================== The data are archived in two coordinate systems, IdaSE and IHG (1950). IdaSE Idacentric Solar Ecliptic (IdaSE) is a Ida centered coordinate system defined by the primary vector along the instantaneous Ida->Sun (ISun) line and the Earth's ecliptic north pole (ENP) as the secondary vector. In this coordinate system: X is the ISun unit vector taken to be positive towards the sun. Y is the formed by the unitized cross product ENP x ISun Z completes the right handed set (Z = X x Y) such that the X-Z plane contains the ecliptic north pole. The data are also provided in inertial heliographic (epoch 1950) coordinates. The radial direction is taken along the instantaneous Sun->S/C line, positive away from the sun. Latitude is the angle the radial vector makes with the sun's equatorial plane at the reference epoch, positive above the equator. Longitude is measured from the longitude of the ascending node. At the reference epoch, the inclination of the Sun's north pole was 7 deg 15 min and the longitude of the ascending node can be computed using the formula: Node = 74 deg 22 min + 0.84 min (year - 1900)

These data are available on-line from the Planetary Data System (PDS) at:

Alternate Names



  • Planetary Science: Fields and Particles

Additional Information


Questions and comments about this data collection can be directed to: Dr. Edwin V. Bell, II



NameRoleOriginal AffiliationE-mail
Dr. Margaret Galland KivelsonGeneral ContactUniversity of California, Los
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