Abstract :
Following its highly successful survey of the latitudinal structure of the heliosphere under near-minimum solar activity conditions, the Ulysses space-probe embarked in 1998 on a second out-of-ecliptic orbit of the Sun. This second high-latitude survey will culminate near solar maximum, offering a unique opportunity to study the polar regions of the heliosphere at a time when the relatively simple, dipolar structure encountered near solar minimum has been replaced by a much more complex configuration. In this paper, an overview is given of the key features of the heliosphere during the rising phase of cycle 23 as revealed by the data acquired aboard Ulysses during the descent to the south polar regions. Particular emphasis is placed on the evolution of the solar wind stream structure, and its effect on the energetic particle fluxes observed at Ulysses. The recent findings are compared with observations acquired at the same location during the first orbit.
