This report is the extension to the year 2015 of a previous series of documents (Parthasarathy et al., 1986; Parthasarathy and King, 1991) showing the trajectories of heliospheric spacecraft. These earlier documents carried information through 1999 for many spacecraft and have recently been made network-accessible as a companion to this document. This document and its predecessors are accessible from http: / /

The present document carries heliocentric trajectory information for the Ulysses and Voyager 1 and 2 and Galileo spacecraft. As a special case the Earth-return trajectory for the International Cometary Explorer (ICE) spacecraft, covering 1983-2014, was included in the 1991 report and will not be repeated herein.

For the spacecraft covered in this report, that is, those expected to be active in the year 2000 and beyond, the authors include information back to the years of their launches but do not repeat pre-2000 information for spacecraft like the Pioneers, which have become inactive. Minor discrepancies in pre-2000 data between the 1991 report and this report result from effects of orbit maneuvers, this report's use of "True-of-Date" equinoxes, etc.; data in this report are more accurate.

The information content includes a series of tables covering the following:

1. Radial distances, heliographic latitudes, and ecliptic plane longitudes of the Voyager
and Ulysses spacecraft, given (a) at the start of each year and (b) on the days of extreme
polar latitudes of Ulysses.

2. Radial distance and Earth-Sun-Probe (ESP) angle projected into the ecliptic plane for
the Galileo spacecraft at monthly resolution from November 1989 through December
1995 and an accompanying algorithm for computing this angle for the Jupiter-Galileo
system for 1996 and later, when Galileo had attained a Jovian orbit.

3. Radial distance, ESP angle projected into the ecliptic plane, and "true" ESP angle
(computed in three dimensions) for the Ulysses spacecraft at monthly resolution for
November 1990 through December 2015.

The information content also includes a series of plots covering the following:

1. Voyager 1 and 2 radial distances and heliographic latitudes, 1977-2015.

2. Similar plots for Ulysses, 1990-2015.

	3. A series of plots showing the latitude and longitude on the disk of the Sun as seen
from Earth where the radius joining the Sun's center to Ulysses passes the solar surface.
This iii
plot does not account for finite solar wind transit times from the Sun to Ulysses. Two symbols are
used, corresponding to Ulysses' being on the Earth side of the Sun and being on the other side.
(These plots were created at the suggestion of Dr. Miriam Forman.)

4. A Johns Hopkins University/Applied Physics Laboratory JHU/APL)-provided plot showing
the trajectory of the Near-Earth Asteroid Rendezvous (NEAR) spacecraft for February 1996
(launch) through 1997 and 1999 encounters with Mathilde and Eros. A limited amount of data
relevant to heliospheric studies was accumulated during this mission.

5. A plot showing the expected October 1997 to July 2004 flight of Cassini to Saturn via Venus
(two swingbys) and Earth (one). Again, only limited data relevant to heliospheric studies will be

Higher resolution trajectory data for the spacecraft covered herein are available from NSSDC's
page Descriptions of the spacecraft, their
experiments, and the data sets therefrom are available from pages in the NSSDC/space physics tree
of World Wide Web pages, which starts at http: / /

The authors welcome feedback on this report and its information content. Any comments on the
post-2015 era they will save for their successors who will hopefully create the next in this series of
heliospheric trajectory documents.

                                                               	R. Parthasarathy

                                                              	J. H. King
R. Parthasarathy, Hills, H. K., Couzens, D. A., King, J. H., Trajectories of Pioneers 6-11, Helios A and B, and Voyagers 1 and 2, NSSDC Report 86-03, 1986. R. Parthasarathy and King, J. H., Trajectories of Inner and Outer Heliospheric Spacecraft, NSSDC Report 91-08, 1991.
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