Burnham's Celestial Handbook: An Observer's Guide to the Universe Beyond the Solar System by Robert Burnham Jr. (Dover Books, 1983). Although the science in this three-volume work is now quite out of date, this is far and away the most interesting and readable treatment of the sky and all of its wonders. It summarizes the legends behind almost every constellation and describes in great detail hundreds of clusters, nebulae, and other objects. Burnham was an eccentric who worked for years at the Lowell Observatory in Flagstaff, Arizona. When he lost his position there he drifted through various states of homelessness, passing away in a San Diego park in 1996. Burnham never really profited from the books, but tens of thousands of amateur astronomers know the 1,600-plus pages intimately.
Star Names Their Lore and Their Meaning by Richard H. Allen (Dover, 1963). The quintessential reference on the origins of star and constellation names.
The New Solar System, Fourth Edition by J. Kelly Beatty, Andrew Chaikin, et al. (Cambridge University Press, 1998). This is about as technical as one can get without tripping the reader up with jargon. It features chapters on each of the major bodies of the solar system and extensive detail on the smaller ones as well. Some 30 authorities in planetary studies contributed.
Secrets of the Astronauts
The U.S. space program has inspired a copious collection of tales, replete with heroic adventure, technological sorcery, and bureaucratic derring-do. By far the best is the deservedly famous The Right Stuff by Tom Wolfe (Bantam Books, 1983). A brilliant piece of journalism and an all-around great read, The Right Stuff explores in great detail the astronaut training program, the psychology of the test pilots who became the early astronauts, and the lives of the Mercury crew--warts and all.
The Apollo program is well documented in A Man on the Moon by Air & Space contributor Andrew Chaikin (Penguin USA, 1998). This excellent narrative, which describes the personalities behind the program as well as the technology, inspired the acclaimed HBO miniseries "From the Earth to the Moon" (video) (DVD).
The astronauts have done their share of writing as well. The best of this category, hands down, is Carrying the Fire: An Astronaut's Journeys by Michael Collins (Adventure Library, 1998). As a writer, Collins is the Lindbergh of the astronaut corps. Buzz Aldrin and Malcolm McConnell wrote Men from Earth (Bantam, 1989) to offer not only an account of Aldrin's spaceflight experiences but also a picture of the U.S. and Soviet efforts during the moon race.
The shuttle program has spun off its own set of scribes. On his mission, Jeff Hoffman did something every astronaut should: He brought a tape recorder on the shuttle and noted his thoughts and experiences. The results, Astronauts Diary (Caliban, 1986), have a striking immediacy. Entering Space: An Astronaut's Odyssey by Joe Allen (Stewart, Tabori & Chang, 1987) is a nice coffee table collection of images and text, probably the best book by a shuttle astronaut.
Finally, for a juicy expose of what went wrong during the Mir-shuttle program of 1994 to 1998, check out Bryan Burroughs' Dragonfly : Nasa and the Crisis Aboard Mir (HarperCollins, 2000), based in part on interviews with unhappy crew members.