Tracking facilities of NASA’s Deep Space Network, located at Goldstone, California, and in Spain and Australia, supported Pioneer Saturn during interplanetary flight and encounter. Pioneer’s radio signals, traveling at the speed of light, took 85 minutes to reach Earth from Saturn, a round-trip time of almost 3 hours, somewhat complicating ground control of the spacecraft. Almost 10,000 commands were sent to the spacecraft in the 2-week period before closest approach. Continued communications should be possible through at least the mid 1980’s. After the spacecraft passed Saturn, it headed out of the solar system, traveling in the direction the solar system moves with respect to the local stars in our galaxy and in approximately an opposite direction from its sister spacecraft, Pioneer 10. Both spacecraft have plaques attached to them which contain a message from Earth for any intelligent species that may intercept the spacecraft during their endless journeys through interstellar space. Pioneer Saturn Scientific Instruments Instrument Principal Investigator Experiment Objective Helium vector Edward J. Smith Magnetic fields magnetometer Jet Propulsion Laboratory Fluxgate Mario Acuña Magnetic fields magnetometer Goddard Space Flight Center Plasma analyzer John H. Wolfe Solar plasma Ames Research Center Charged particle John A. Simpson Charged particle University of Chicago composition Cosmic ray telescope Frank B. McDonald Cosmic ray energy Goddard Space Flight Center spectra Geiger tube James A. Van Allen Charged particles telescope University of Iowa Trapped radiation R. Walker Fillius Trapped radiation detector University of California, San Diego Asteroid/meteoroid Robert K. Soberman Asteroid/meteoroid detector[1] General Electric Co. and astronomy Philadelphia Drexel University Meteoroid detector William H. Kinard Meteoroid detection Langley Research Center Radio transmitter John D. Anderson Celestial mechanics and DSN Jet Propulsion Laboratory Ultraviolet Darrell L. Judge Ultraviolet photometer University of Southern photometry California Los Angeles Imaging Tom Gehrels Photo imaging and photopolarimeter University of Arizona, Tucson polarimetry Infrared radiometer Andrew Ingersoll Infrared thermal California Institute of structure Technology Radio transmitter Arvydas J. Kliore S-band occultation