The Themis spacecraft B and C have been renamed ARTEMIS P1 and P2 and moved around in cis-lunar space from Earth orbit to Lunar orbit.

This transfer involved libration point orbits, as discussed in the 2010 NASA news article ARTEMIS - The First Earth-Moon Libration Orbiter and can be seen in the cool orbit plots there, also shown below.

But the JPL Horizons web interface currently only shows the two spacecraft's lunar orbits from January to August 2017, specifically 2017-Jan-31 00:01 to 2017-Aug-03 00:01.

Are kernels for the cis-lunar acrobatics in 2010 available anywhere in the JPL's web site, or are these not publicly accessible?

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above: "Illustration of Artemis-P1 liberations orbits. Credits: NASA/Goddard",

below: "Illustration of Artemis-P1 liberations orbits, side or ecliptic view. Credits: NASA/Goddard"

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1 Answer 1


It was hosted on the Berkely SSL server.

Kernels located here: http://themis.ssl.berkeley.edu/data/themis/spice_kernels/

P.S: Thanks to David Stansby's HelioPy documentation.

  • $\begingroup$ Check /ephem/logs/<sc> where <sc> is the spacecraft name $\endgroup$
    – ASRI_306
    Commented Jul 2, 2019 at 11:04
  • $\begingroup$ Just did, check this one. Should work. $\endgroup$
    – ASRI_306
    Commented Jul 2, 2019 at 11:07
  • $\begingroup$ Excellent! Okay I'll fire up some old Python and try to read them, thank you! $\endgroup$
    – uhoh
    Commented Jul 2, 2019 at 11:09

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