******************************************************************************* Revised: Jun 15, 2007 Pioneer 11 Spacecraft / (Sun) -24 http://nssdc.gsfc.nasa.gov/nmc/tmp/1973-019A.html BACKGROUND: This mission was the 2nd sent to the Jupiter system and the first to investigate the planet Saturn and its ring system. Closest approach to Jupiter cloud-tops was 42,000 km on Dec 3, 1974. It came within 21,000 km of Saturn's cloud-tops on Sep 1, 1979. Pioneer 11, like Pioneer 10, used Jupiter's gravitational field to alter its trajectory. Science operations and daily telemetry ceased on September 30, 1995 when the RTG power level was insufficient to operate any experiments. Launched : 1973-04-06 at 02:11:00 UTC On-orbit dry mass : 259 kg Nominal Power Output: 165 W SPACECRAFT TRAJECTORY: Trajectory provided by JPL Navigation Team. JPL Multimission NAV and Solar System Dynamics Group source files: PN11A, PN11AB ("AB" is not a typo), PN11C, PN11D, PN11E, PN11FE ("FE" is not a typo), PN11G, DE118 The circumstances pertaining to the regeneration of the spacecraft trajectory source files, PN11*, are not well known. DE118 is a standard JPL planet ephemeris for the P11 Jupiter encounter. NOTE: This trajectory is suitable for general historical purposes, but should be used cautiously for high precision or tracking data applications. This is due to potential dynamical mismatches between the Pioneer-11 era models and the current modern solutions used by Horizons; for example, the old DE-118 planetary ephemeris solution and the Lieske E3 satellite theory of JUP035, SAT050, etc., as compared to what is used now. For example, if the Pioneer-11 solutions used here incorporate planet or satellite ephemeris corrections estimated at the time, distance from the satellites returned by Horizons could be slightly different relative to the original solutions. However, the coordinate system transformation from the original DE-118 planetary ephemeris to the modern ICRF frame IS known and computed by Horizons. ******************************************************************************* ******************************************************************************* Ephemeris / WWW_USER Fri Dec 12 17:54:23 2025 Pasadena, USA / Horizons ******************************************************************************* Target body name: Pioneer 11 (spacecraft) (-24) {source: pioneer_11_merged} 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 ******************************************************************************* $$SOE 2461041.500000000 = A.D. 2026-Jan-01 00:00:00.0000 TDB EC= 2.147473171121412E+00 QR= 9.345183988753169E+00 IN= 1.662894410918374E+01 OM= 1.603296465735844E+02 W = 1.279117686985225E+01 Tp= 2444207.394899716135 N = 4.243530042994272E-02 MA= 7.143603073997849E+02 TA= 1.103529665213967E+02 A =-8.144141600818630E+00 AD= 9.999999999999998E+99 PR= 9.999999999999998E+99 $$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 = 'Pioneer 11' OUT_UNITS = 'AU-D' START_TIME = '2026-01-01' STEP_SIZE = '1y' STOP_TIME = '2026-01-02' TABLE_TYPE = 'ELEMENTS'