******************************************************************************* Revised: Aug 19, 2022 Voyager 1 Spacecraft (interplanetary) / (Sun) -31 http://www.jpl.nasa.gov/missions/voyager-1/ BACKGROUND See the web-page above for information on the Voyager Mission TIMELINE 1977-Sep-06 Launch from Kennedy Space Center @ 12:56 UTC 1979-Mar-05 Jupiter closest-approach, Io imaging 1980-Nov-12 Saturn encounter, Titan 1990-Jan-01 Interstellar mission begins 1990-Feb-14 Final Voyager image return 1992-Apr-24 Final two-way tracking measurements 1998-Feb-17 Exceeds Pioneer 10 distance (most distant man-made object) 2004-Dec-15 Crosses solar system "bow shock" boundary 2012-Aug-25 Passes heliopause and termination shock boundary SPACECRAFT TRAJECTORY: This trajectory is composed of two merged sections: #1) 1977-Sep-5 to 1981-Jan-1: A patched conic mission-design type trajectory in which the conics were constructed to approximately match specific events, such as satellite encounters, providing a rough accuracy. #2) 1981-Jan-1 to 2100-Jan-1 Refit of tracking data spanning 1981-1992 (end of two-way coherent transponder data). Done in 2022 by R. Jacobson (former Voyager navigation) using DE440 to generate a new solution and prediction. The reconstruction done in 2022 estimated: - Epoch state vector - Constant and stochastic non-gravitational accelerations (to account for the activity of three-axis attitude control system) - Thermal radiation from RTG power sources - Mismodelling of solar pressure - 96 impulsive maneuvers through Feb 1992 Note there has been no new tracking data possible since 1992. This is a different issue from on-board telemetry, which continued beyond that date. The 2022 update refit the existing old tracking data using modern approaches and standards to allow consistent extrapolation to 2100. Formal predicted geocentric pointing uncertainty on 2030-Jan-1: RA +/- 1.701 arcseconds, DEC +/- 1.535 arcseconds This uncertainty is consistent with the new solution's difference with the A54206 prediction made in 1990. Tracking data used in 2022 solution: Points Type First point Last point residual rms 2366 F2 01-JAN-1981 05:14:00 15-APR-1989 08:09:00 0.133 mm/s 2084 F3 07-JAN-1981 12:15:00 24-APR-1992 14:04:00 0.153 mm/s 5191 PRA 01-JAN-1981 03:52:18 20-JAN-1989 14:13:59 228 m 67 SRA 04-MAR-1989 10:58:56 13-OCT-1991 04:49:30 227 m ******************************************************************************* ******************************************************************************* Ephemeris / WWW_USER Fri Dec 12 17:53:46 2025 Pasadena, USA / Horizons ******************************************************************************* Target body name: Voyager 1 (spacecraft) (-31) {source: Voyager_1_ST+refit2022_m} Center body name: Solar System Barycenter (0) {source: DE441} Center-site name: BODY CENTER ******************************************************************************* Start time : A.D. 2026-Jan-01 00:00:00.0000 TDB Stop time : A.D. 2026-Jan-02 00:00:00.0000 TDB Step-size : 1 calendar years ******************************************************************************* Center geodetic : 0.0, 0.0, 0.0 {E-lon(deg),Lat(deg),Alt(km)} Center cylindric: 0.0, 0.0, 0.0 {E-lon(deg),Dxy(km),Dz(km)} Center radii : (undefined) Keplerian GM : 2.9630927493968080E-04 au^3/d^2 Output units : AU-D, deg, Julian Day Number (Tp) Calendar mode : Mixed Julian/Gregorian Output type : GEOMETRIC osculating elements Output format : 10 Reference frame : Ecliptic of J2000.0 ******************************************************************************* JDTDB EC QR IN OM W Tp N MA TA A AD PR ******************************************************************************* $$SOE 2461041.500000000 = A.D. 2026-Jan-01 00:00:00.0000 TDB EC= 3.728161413660308E+00 QR= 8.789648923842631E+00 IN= 3.578877464272717E+01 OM= 1.791018654564524E+02 W = 3.382100475026447E+02 Tp= 2444227.259379382245 N = 1.705465958449854E-01 MA= 2.867611499564872E+03 TA= 1.016755789238694E+02 A =-3.221821436162676E+00 AD= 9.999999999999998E+99 PR= 9.999999999999998E+99 $$EOE ******************************************************************************* TIME Barycentric Dynamical Time ("TDB" or T_eph) output was requested. This continuous coordinate time is equivalent to the relativistic proper time of a clock at rest in a reference frame co-moving with the solar system barycenter but outside the system's gravity well. It is the independent variable in the solar system relativistic equations of motion. TDB runs at a uniform rate of one SI second per second and is independent of irregularities in Earth's rotation. CALENDAR SYSTEM Mixed calendar mode was active such that calendar dates after AD 1582-Oct-15 (if any) are in the modern Gregorian system. Dates prior to 1582-Oct-5 (if any) are in the Julian calendar system, which is automatically extended for dates prior to its adoption on 45-Jan-1 BC. The Julian calendar is useful for matching historical dates. The Gregorian calendar more accurately corresponds to the Earth's orbital motion and seasons. A "Gregorian-only" calendar mode is available if such physical events are the primary interest. REFERENCE FRAME AND COORDINATES Ecliptic at the standard reference epoch Reference epoch: J2000.0 X-Y plane: adopted Earth orbital plane at the reference epoch Note: IAU76 obliquity of 84381.448 arcseconds wrt ICRF X-Y plane X-axis : ICRF Z-axis : perpendicular to the X-Y plane in the directional (+ or -) sense of Earth's north pole at the reference epoch. Symbol meaning [1 au= 149597870.700 km, 1 day= 86400.0 s]: JDTDB Julian Day Number, Barycentric Dynamical Time EC Eccentricity, e QR Periapsis distance, q (au) IN Inclination w.r.t X-Y plane, i (degrees) OM Longitude of Ascending Node, OMEGA, (degrees) W Argument of Perifocus, w (degrees) Tp Time of periapsis (Julian Day Number) N Mean motion, n (degrees/day) MA Mean anomaly, M (degrees) TA True anomaly, nu (degrees) A Semi-major axis, a (au) AD Apoapsis distance (au) PR Sidereal orbit period (day) ABERRATIONS AND CORRECTIONS Geometric osculating elements have NO corrections or aberrations applied. Computations by ... Solar System Dynamics Group, Horizons On-Line Ephemeris System 4800 Oak Grove Drive, Jet Propulsion Laboratory Pasadena, CA 91109 USA General site: https://ssd.jpl.nasa.gov/ Mailing list: https://ssd.jpl.nasa.gov/email_list.html System news : https://ssd.jpl.nasa.gov/horizons/news.html User Guide : https://ssd.jpl.nasa.gov/horizons/manual.html Connect : browser https://ssd.jpl.nasa.gov/horizons/app.html#/x API https://ssd-api.jpl.nasa.gov/doc/horizons.html command-line telnet ssd.jpl.nasa.gov 6775 e-mail/batch https://ssd.jpl.nasa.gov/ftp/ssd/horizons_batch.txt scripts https://ssd.jpl.nasa.gov/ftp/ssd/SCRIPTS Author : Jon.D.Giorgini@jpl.nasa.gov ******************************************************************************* !$$SOF CENTER = '@0' COMMAND = 'Voyager 1' OUT_UNITS = 'AU-D' START_TIME = '2026-01-01' STEP_SIZE = '1y' STOP_TIME = '2026-01-02' TABLE_TYPE = 'ELEMENTS'