Can’t remember where I came across this, but couldn’t pass it up due to the title and it being Harrison. Seems to be a straight up parody of all things space opera but more specifically the Lensman series. Lots of “Gee whiz” and “aw shucks.”
From Amazon: The wild, galaxy-hopping adventures of brash young scientists Jerry Courtenay and Chuck van Chider are at the core of this classic space opera. When the two college students develop a faster-than-light space drive in their homemade workshed, they decide to sneak it aboard their football team’s airplane as a prank. The boyish plan backfires, however, and the boys find themselves, along with their crush Sally and the seemingly loveable school caretaker, Old John, hurtling through the solar system towards Titan—an icy moon of Saturn inhabited by hideous ice creatures. Titan and the 20th century are only square one as the foursome becomes embroiled in a vast, intergalactic, century-jumping battle.
I don’t know whether it’s a parody, but it is in the family oft young adult novels that include Asimov’s Lucky Starr series. As a child of the 1950’s, it seemed to me to be a logical step up from “Space Patrol” and “Tom Corbett”. The book was a fun read in the early 1960’s as are most of Harrison’s.