References

83. N. Longdon, "European Rendezvous", Spaceflight, November 1992, p. 366.
84. ESA's Report to the 28th COSPAR Meeting, on. cit., pp. 41-45.
85. Annual Report, ESA, 1993, pp. 39-40 and 1994, pp. 37-38.
86. W. Harwood, "Ulysses Begins Survey of Solar Polar Activity, Space News, 11-17 July 1994, p. 18.
87. C. Covault, "Ulysses Exploring South Pole of Sun", Aviation Week and Space Technology, 12 September 1994, pp. 50-51.
88. "Ulysses Probes the Sun's South Pole", Spaceflight, December 1994, pp. 417-418.
89. "Ulysses Finds Differences in Solar Wind at High, Low Latitudes", Spaceflight, September 1995, pp. 304-305.
90. N. Angold, et al, "Ulysses Operations at Jupiter-Planning for the Unknown", ESA Bulletin, No. 72, 1992, pp. 44-51.
91. R.G. Marsden and K.-P. Wenzel, "The Ulysses Jupiter Flyby - The Scientific Results", ESA Bulletin, No. 72, 1992, pp. 52-59.
Adapted from: Europe and Asia in Space 1993-1994, Nicholas Johnson and David Rodvold [Kaman Sciences / Air Force Phillips Laboratory]

Ulysses

The Ulysses mission, designed to collect the first close observations of the solar polar regions and 3-dimensional heliosphere data, completed the first of its major objectives in 1994 by reconnoitering the Sun's southern hemisphere. Originally part of a two-spacecraft program between ESA and NASA called the International Solar Polar Mission, Ulysses became a solitary program in 1981 when the US companion spacecraft was canceled. Ulysses then experienced a four-year launch delay in the aftermath of the Space Shuttle Challenger accident, finally being launched in July, 1990, during the STS-41 mission. However, before reaching the Sun the 370-kg spacecraft first had to fly by Jupiter in February, 1992, to receive a gravity-assisted deflection out of the ecliptic and back toward the center of the solar system.

Some 28 months after its encounter with Jupiter, Ulysses began its survey of the Sun's southern latitudes in earnest. From June to October, 1994, the craft monitored the electromagnetic and charged particle environment, reaching a maximum solar latitude of -80 degrees in September. Ulysses' trajectory will carry it back across the ecliptic in early 1995 with a closest approach of 200 million km and then over the northern hemisphere for another polar campaign during June-September. After completing this survey of the Sun, Ulysses will follow a trajectory back toward the orbit of Jupiter. Aphelion should occur in 1998 although Jupiter will be more than 100 million miles away. If Ulysses is still functioning, a second, close-up survey of the Sun could commence late in the year 2000 when the spacecraft once again approaches the solar southern regions.

The spin-stabilized (5 rpm) spacecraft is powered by a US-supplied radioisotope thermoelectric generator. A complex array of more than a dozen scientific instruments comprise the 55-kg payload. The prime contractor was Dornier with British Aerospace (now Matra Marconi), DASA, and Fokker as major subcontractors (References 83-91).

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