NASA's Cassini spacecraft has successfully executed its historic first-ever dive through the narrow gap between the planet Saturn and its rings, marking the beginning of the 'Grand Finale' of the 20-year-long journey.<br/><br/>The spacecraft is in the process of beaming back science data collected during its passage, through NASA's Deep Space Network Goldstone Complex in California's Mojave Desert. As it dove through the gap, Cassini came within about 3,000 kilometres of Saturn's cloud tops and within about 300 kilometres of the innermost visible edge of the rings. While mission managers were confident Cassini would pass through the gap successfully, they took extra precautions with this first dive, as the region had never been explored. The gap between the rings and the top of Saturn's atmosphere is about 2,000 kilometres wide.<br/><br/>Cassini was programmed to collect science data while close to the planet and turn toward Earth to make contact about 20 hours after the crossing. Its next dive through the gap is scheduled for May 2.