README file for the IBEX ephemeris data in SPICE kernel format
https://spdf.gsfc.nasa.gov/pub/data/ibex/orbits/00readme.txt
2023 March 17

Curator: leonard.n.garcia@nasa.gov

IBEX - Interstellar Boundary Explorer was launched in October 2008. 
It was placed into an earth-centered elliptical orbit with an apogee large enough to experience notable 
perturbations from the Moon requiring periodic thruster firings to maintain the orbit. 

In 2011 IBEX was placed into a modified orbit that avoids these major perturbations. Articles describing this orbit are at: 
http://ibex.swri.edu/archive/2011.11.14.shtml
and
http://ibex.swri.edu/mission/operations.shtml


This directory contains a SPICE kernel file holding the definitive orbit data from the start of mission until nearly the file's modification date and predictive orbit data until 2032.

older/ - a directory containing earlier IBEX ephemeris SPICE kernels. Each of these contain both definitive and predictive data but the time ranges may vary.

A summary of the contents of these files may be viewed using the SPICE utility programs brief or commnt -r, for a more detailed view. The brief and commnt SPICE utility programs are available at:
https://naif.jpl.nasa.gov/naif/utilities.html

For more information on using SPICE kernels see the JPL NAIF SPICE Toolkit website: 
https://naif.jpl.nasa.gov/naif/toolkit.html