Ulysses Has Close Encounter With Jupiter as It Rockets Toward Sun

The Ulysses spacecraft boomeranged past Jupiter on Saturday, flying through deadly radiation and an orbiting ring of volcanic debris on its way to study the sun.

“This is a historic moment for Ulysses,” said Ed Smith, NASA’s project scientist at the Jet Propulsion Laboratory in Pasadena. “It successfully passed Jupiter. . . . We’re ready to begin our primary mission to explore the poles of the sun.”

Ulysses began its $750-million mission Oct. 6, 1990, when it was launched from the space shuttle Discovery. The mission is a joint project of the National Aeronautics and Space Administration and the European Space Agency.

The spacecraft made its closest approach to Jupiter seconds before 4:01 a.m. Saturday, flying about 235,000 miles over the planet’s cloud tops at a speed of 61,249 m.p.h., said Don Meyer, deputy mission operations manager.

It was the fifth spacecraft to visit the solar system’s largest planet. It also was the first time Europe has sent a spacecraft to another planet, Smith said.

During the close encounter, Ulysses was located between the orbits of Io and Europa, two of Jupiter’s moons. The spacecraft was 416 million miles from Earth, but had traveled a curving path of almost 624 million miles to reach Jupiter.

Mission controllers played the theme music from the film “2001: A Space Odyssey.”

“They were having a lot of fun,” Smith said. “They pretended they were on ‘Star Trek’ or something.”

The purpose of the flyby was to let Ulysses use Jupiter’s gravity as a slingshot, which made the spacecraft dive southward out of the plane in which the planets orbit the sun. That will allow Ulysses to observe the sun’s south polar latitudes from June to September, 1994, and its northern polar regions a year later. Ulysses needs only to get out of the plane of the planets to study the sun’s poles, and does not have to approach the sun.