Mission Objectives Overview  ===========================    The primary mission of the Ulysses spacecraft was to    characterize the heliosphere as a function of solar latitude.    The heliosphere is the vast region of interplanetary space    occupied by the Sun's atmosphere and dominated by the outflow    of the solar wind.  The periods of primary scientific interest    are when Ulysses was at or higher than 70 degrees latitude at    both the Sun's south and north poles.  On 26 June 1994, Ulysses    reached 70 degrees south.  There it began a four-month    observation from high latitudes of the complex forces at work    in the Sun's outer atmosphere -- the corona.    Scientists have long studied the Sun from Earth using Earth-    based sensors.  More recently, solar studies have been    conducted from spaceborne platforms; however, these    investigations have been mostly from the ecliptic plane (the    plane in which most of the planets travel around the Sun) and    no previous spacecraft have reached solar latitudes higher than    32 degrees.  Now that Ulysses high latitude data is available,    scientists from the joint National Aeronautics and Space    Administration (NASA)-European Space Agency (ESA) mission are    obtaining new and better understanding of the processes going    on at high solar latitudes.    Scientists have long been aware of differences between the    polar regions of the Sun and lower latitudes.  Sunspots are    only seen at lower latitudes, and photographs of the solar    corona take during solar eclipses often showed dark regions    over the poles.  The solar corona consists of hot gasses (over    1,000,000 degrees); at this temperature the gravitational field    of the Sun can not prevent escape of coronal gas as the solar    wind.  However, the Sun has a global magnetic field.  Many of    the solar magnetic field lines that leave the solar surface    return to the surface, but some of the field lines,    particularly those over the poles, extend deep into    interplanetary space.  The solar wind expands into    interplanetary space along these field lines, and the regions    (known as coronal holes) of the corona from which the hot gas    escapes are dark because of the low gas density.  The    properties of the Sun's polar magnetic field are poorly    understood, and they have an important influence on the escape of    the solar wind.  The complex processes that heat and accelerate    the solar wind are not well understood, and Ulysses    observations over the poles should provide important new    information on how the solar wind expands from the Sun that    will aid scientists in understanding these processes.  The    magnetic field also exerts a crucial influence on matter    arriving near the Sun from the Milky Way galaxy and from the    nearby interstellar medium.  Incoming cosmic rays are subjected    to forces exerted by the magnetic field.  The structure of the    Sun's magnetic field is thought to favor entry of cosmic rays    by way of the Sun's polar regions.  Scientists hope that    Ulysses can shed some light on the extent to which the galactic    cosmic rays observed at Earth use this route and on the ways in    which their properties are modified as a result.  Scientists    also hope to gain more knowledge of the intensity and    properties of the cosmic rays far from the Sun.    Jupiter Encounter    -----------------      The primary aim of the flyby was to place the spacecraft in      its final heliocentric out-of-ecliptic orbit with a minimum      of risk to the onboard systems and scientific payload.      Scientific investigations at Jupiter are a secondary      objective of the mission.  Nevertheless, the opportunity to      study Jupiter's magnetosphere was exploited to the greatest      extent possible.      Jupiter is a strongly magnetized, rapidly rotating planet.      Its magnetosphere is the largest object in the solar system,      a fact reflected in the long interval of 12 days from 2 to 14      February (days 033 to 045 of 1992) that it took for Ulysses      to travel through it.  The large Galilean satellites are      embedded within the magnetosphere and Io is known to be a      prolific source of ions and neutral particles.  Ions,      predominantly of sulfur and oxygen, are distributed around      the orbit of Io to form a large torus.  Electrons and ions      from Io, Jupiter's ionosphere and the solar wind are all      present and are transported throughout the magnetosphere.  A      substantial fraction of these particles are accelerated to      extremely high energies to form intense radiation belts.      Upstream of the magnetosphere, in the free-streaming solar      wind, a detached bow shock forms which slows the solar wind      and allows it to be deflected around the magnetosphere.  A      wide variety of complex physical phenomena are available for      study.    References    ==========      Description of the Jupiter Encounter Mission Objectives adapted      from [MARSDEN&WENZEL1992]).