Watching the Rockets Go Up: Charles Coombs, Mystery of Satellite 7 (Philadelphia: Westminster Press, 1957)
Also author of: Celestial Space Inc., The Case of the Purple Mark, Treasure Under Coyote Hill,.
Coombs started off as a hack writer for adults and gradually moved into children’s fiction. In a short note at the back he mentions not writing down to children, but there is a passivity to his protagonists which I associate with later YA fiction.
Straightforward enough: Steve and his friend Karl live in Florida where their fathers work on private statellite launch projects—the satellites are for tv communication. The boys are allowed a surprising amount of involvement—Karl helps check equipment.
Seven of the eight satellites have gone wrong and there is a suspicion of sabotage.
Mostly the boys sit around, listen and watch. They stumble across the saboteurs, are tied up, and are rescued by a journalist.
Scientific material in this book is handled in an interesting way, in that apparent explanations turn out to be mere description. “Spools spun thin wires through complicated recording devices. Small varicoloured lights flashed and pulsated like fireflies on parade.” (18) and “Until the firing switch was thrown closes, there was no way of anticipating what numerous unsuspected opponents lay in wait to reach out and ambush the project. It could be a slight cloud in one of the fuel lines. It might be a microscopic crack in a turbopump blade. Vibration might sever the filament of a critical subminature vacuum tube.” (20) You can read this stuff and think you are learning from it, until you realise you can't piece any of it together. Classic hard-sf in other words.
See http://www.flyingturkeys.com/gsg/gsgcoombs.html for more.