New Horizons Solar Wind Around Pluto Trajectory Files - Overview
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Content
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This collection contains New Horizons (NH) spacecraft trajectory in various 
reference frames for the primary and extended missions.

One set of files contains data at an interval of about one (1) day for the 
duration of the primary and extended missions.  A second set of files contains 
higher variable cadance data for the Pluto Time of Closest Approach (TCA) plus 
or minus thirty (30) days.

One Day Interval Files
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The sampling period is 86400 NH spacecraft seconds, about one day, over
the time period from launch through the end of 2028. The data will contain
placeholder flags for some (future) dates where there is not enough
information to predict the spacecraft location accurately. Locations before
2022-JUN-01 01:36:23.288 come from 'reconstructed' SPICE kernels, whereas
later locations are estimated from 'predicted' SPICE kernel information.

The reference frames included are
  Heliocentric Aries Ecliptic Date (HAE_DATE) a.k.a. Solar Ecliptic (SE) Date, 
  Heliocentric Aries Ecliptic J2000 (HAE_J2000) a.k.a Solar Ecliptic (SE) J2000,
  Heliocentric Earth Ecliptic (HEE), 
  Heliocentric Earth Equatorial (HEEQ) a.k.a. Stonyhurst heliographic,
  Heliographic Inertial (HGI) a.k.a. Heliocentric Inertial (HCI),
  Heliographic (HG) a.k.a. Heliocentric Inertial (HCI) or Carrington system, 
  J2000, 
  Jupiter International Astronomical Union (IAU_JUPITER), 
  Jupiter J2000, 
  Pluto International Astronomical Union (IAU_PLUTO), and
  Pluto J2000.


Pluto TCA Files
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The time coverage is the Pluto Time of Closest Approach (TCA) plus or minus 
approximately 30 days, sampled at 1 second intervals within two hours of
TCA, at 10 second intervals from two to four hours before and after TCA, 
at 60 second intervals from four to twelve hours before and after TCA, and 
600 second intervals from twelve hours to thirty days before and after TCA.

The reference frames included are
  Heliographic (HG) a.k.a. Heliocentric Inertial (HCI) or Carrington system, 
  J2000, 
  Pluto International Astronomical Union (IAU_PLUTO), and
  Pluto J2000.


The data were presumably prepared by the SWAP team.  In the PDS3 data, the 
Producer Institution Name was listed as Southwest Research Institute.  The 
PDS4 migration was performed by SBN personnel, who are credited as an editor 
of this collection.

PDS3 to PDS4 Migration Notes
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In PDS3, these files were supplied as one concatenated file.  There were 
multiple versions that were updated with each release.  For the migrated 
PDS4 archive, only a single instance of each file was retained. 

The PDS3 labels were not retained in the migrated PDS4 archive but are 
accessible in archival copies of the PDS3 datasets retained in the NSSDCA 
deep archive.


2025-11-05, P. Lawton