If you've opened a fortune cookie, you've probably read an aphorism, like this one, 'The world may be your oyster, but that doesn't mean you'll get its pearl.' In just a few words this quote tells the reader a lesson about life, that you have nearly limitless possibilities, but not all of them lead to a great reward.
The exploration of Neptune has only begun with one spacecraft, Voyager 2 in 1989. Currently there are no approved future missions to visit the Neptunian system. NASA, ESA and also independent academic groups have proposed future scientific missions to visit Neptune.
In late 2013, New Horizons passed within 1.2 AU (180,000,000 km; 110,000,000 mi) of the high-inclination L5 Neptune trojan 2011 HM102, which was identified shortly before by the New Horizons KBO Search Survey team while searching for more distant objects for New Horizons to fly by after its 2015 Pluto encounter.