Uranus Archives

A planetary alignment that comes once every 176 years let a single spacecraft slingshot past all four giant planets in one journey, and NASA nearly threw the chance away to help pay for the Space Shuttle — only for JPL engineers to quietly build the full tour into Voyager 2 anyway, the only craft ever to reach Uranus and Neptune.

Once every 176 years, the four giant planets line up so a single spacecraft can slingshot from one to the next in a single...