Chasing New Horizons by Alan Stern and David Grinspoon

When NASA’s New Horizons spacecraft flew past Pluto and its moons in July 2015, returning remarkable images and other data of these worlds, it was a culmination of an effort much longer than most people recognized. They knew that the spacecraft had been traveling from Earth for nine and a half years to reach Pluto, and probably understood that the spacecraft had been in development for several years before its January 2006 launch. But convincing NASA to fly a mission to Pluto in the first place, and then keeping the agency sold on the mission, was an effort as long and as difficult as the scientific and technical challenges of New Horizons.  The funding for the Pluto mission was an extended and uphill battle, one that I found somewhat fascinating.  The orbit of Pluto is 248 years, and so if we didn't fund a mission when it was relatively close to us, it could be several lifetimes before we could do it again. 
After all those efforts to get a Pluto mission launched, the actual flight of the mission to Pluto might seem a little anticlimactic, given the success it ultimately enjoyed in its flyby. But the book does go into detail about the years of work that went into the planning for the flyby and the issues along the way, including the computer problem just a week and a half before closest approach that put the flyby into jeopardy. It also, of course, recalls the joy of the successful flyby and the gorgeous planet itself.