Another of the first SF books I read, back in fifth grade....

A mystery novel, really, set at White Sands in 1981. The US is portrayed as a security state, and the action's built around a bunch of missing scientists who really shouldn't have been aboard rockets, even if they helped design 'em. The main character's 18, drives a Morgan trike, and asks inconvenient questions. He's trying to figure all this out. There's an FBI agent who seems to be helping, and another--extremely talented--guy who's probably trying to obstruct things.

Everything sorts out on the last page.

Oh, yeah. Douglas Smith is a character in the story. He's presented as the son of George O. Smith in a way that suggests that Del Ray/St John was probably writing an actual person--presumably a friend--into this novel. Anyone know whether that's true? ( )