2030~2040年是指 可能的發射日期喔
With luck, a Uranus missions would launch by 2034. But if NASA misses that launch time, the opportunity could be gone for a while.
“For Uranus, although the frequency of good launch dates falls off after 2034, there are still good opportunities through 2036. For Neptune, however, after 2030 it is pretty barren, owing to a lack of Jupiter gravity assists, for another 12 years, to about 2041 or so,” says Mark Hofstadter at the NASA Jet Propulsion Laboratory.
路途還要花上14年 因為他們是軌道船 不是飛掠式的 速度比較慢
The journey would take at least 14 years
就算一切順利 也要2040年代末 ~2050年代 才能進入天王星 or 海王星的軌道了...
慢慢等吧 :