|
(詳細はEarth to Jupiter, the probe’s exploration of the Jovian atmosphere, and an Orbiter tour consisting of 11 orbits of Jupiter constituted Galileo’s Prime mission. On Jupiter arrival Day (7 December 1995), the Galileo spacecraft was given a gravity-assist from Io and then subjected to the Jupiter orbit insertion (JOI) maneuver, which slowed the spacecraft down and let it be “caught” by the planet. These two actions placed the Orbiter on its proper trajectory to tour the Jovian moons. The Jupiter orbit insertion maneuver involved an orbit around the planet, which is referred to as the spacecraft’s “zeroth” orbit. The spacecraft’s “first,” and by far longest, orbit around Jupiter followed the JOI and lasted nearly seven months. On 27 June 1996, this initial orbit culminated in a close encounter with Ganymede, the largest of the four Galilean satellites. After the first Jupiter orbit of seven months, subsequent orbits were much shorter, ranging from one to two and a half months. The Prime Mission orbiter tour included four close encounters with Ganymede, three with Europa, and three with Callisto. No Io encounters were planned for the Prime Mission (besides the flyby on arrival day) because mission scientists feared that the high radiation levels so close to Jupiter could damage the spacecraft and possibly end the project. The Prime Mission ended in December 1997, two years after Jupiter arrival.〔Michael Meltzer, (''Mission to Jupiter: a History of the ''Galileo'' Project'' ), NASA SP 2007–4231, p. 223-282〕 The Galileo mission used a two-character code to specify each orbit. The first character was the first letter of the name of the moon that would receive a flyby on the orbit, while the second character indicated the number of the orbit. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Timeline of Galileo Jupiter orbiter tour」の詳細全文を読む スポンサード リンク
|