Don Savage
Headquarters, Washington, DC                    July 27, 1995
(Phone:  202/358-1547)

Diane Ainsworth
Jet Propulsion Laboratory, Pasadena, CA
(Phone:  818/354-5011)

RELEASE:  95-125


ULYSSES CLIMBS TO HIGHEST LATITUDE OVER SUN'S NORTHERN POLE

        The European Space Agency's (ESA) Ulysses spacecraft, 
the first probe ever to fly over the poles of the Sun, will 
climb to its maximum latitude of 80.2 degrees north of the 
Sun's equator on Monday, July 31, and survey the solar forces 
at work from this unique vantage point in space.

       The spacecraft will have traveled about 1.86 billion 
miles when it reaches the summit of its trajectory over the 
Sun at 11 a.m. EDT, according to mission operations team 
members at NASA's Jet Propulsion Laboratory, Pasadena, CA.

       All Ulysses operations and science experiments 
continue to go well in this unique, five-year journey out of 
the ecliptic plane.  NASA's tracking facilities near Madrid, 
Spain and at Goldstone, CA, are monitoring the spacecraft 24 
hours a day as maneuvers are performed to keep Ulysses' radio 
antenna pointed to Earth.

       Launched on October 6, 1990, aboard the Space Shuttle 
Discovery, the 810-pound ESA probe was designed to study the 
heliosphere -- that region of space dominated by the solar 
wind -- at all latitudes above and below the Sun's equatorial 
plane.  These high latitude regions have never been explored 
before.

       Named for the legendary Greek adventurer who journeyed 
to the hidden side of the Sun, Ulysses carries nine 
scientific instruments provided by European countries and the 
United States to make detailed studies of solar wind, 
magnetic fields and particles, interplanetary dust and gas, 
and cosmic rays entering the solar system from the Milky Way 
galaxy.  In addition, Ulysses' radio data have been used for 
other experiments to study the Sun's outer atmosphere, or 
corona, and to search for gravitational waves in 
interplanetary space, and the gamma ray burst detector helps 
triangulate the brightest cosmic gamma ray bursts.


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       Today the spacecraft is traveling at about 55,300 
miles per hour with respect to the Sun.  Ulysses will begin 
to descend in latitude as it loops over the northern solar 
polar region.

       On September 29, the spacecraft will complete the 
northern polar pass and begin to journey back out to the 
orbit of Jupiter, reaching Jupiter's distance of 5.4 
astronomical units (about 500 million miles) on April 17, 
1998.  Ulysses will then head back on its high latitude 
trajectory toward the Sun, returning again to its vicinity in 
September 2000.

       Ulysses is managed jointly by NASA and ESA to study 
the regions above the Sun's poles.  The Jet Propulsion 
Laboratory manages the U.S. portion of the mission for NASA's 
Office of Space Science, Washington, DC.

                            - end -

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