"The Planet Strappers" by Raymond Z. Gallun (1961)
"For once his pale eyes flashed. 'You Bright Boys,' he said. 'Especially you, Ramos...! Well, I'm most to blame. I let him hang around, because he was too doggone interested. And driven - somehow. Lucky nothing too bad happened. Last August, when you romantics got serious about space, I made him prove he was over twenty-one...'"
Raymond Z. Gallun (pronounced "Galloon") should be better known than he is. He wrote a number of books, and was quite prominent during sci-fi's golden age in the late 40s and early 50s. Unfortunately his star faded as the 70s began, and he stopped writing shortly thereafter.
"The Planet Strappers" is about a group of young people who set off for the far reaches of the solar system, making most of their own equipment and getting by with a second-hand knowledge of astrophysics. They begin by traveling to the moon in inflatable (yes, inflatable) spacecraft, and after their arrival there they spread out in different directions, finding adventure from Mercury to distant Pluto.
It's a straightforward adventure story, and could have just as easily been set upon the surface of the globe, or the high seas. But the author has a masterful way of both describing characters and setting them into dramatic conflict, a skill not often seen in science fiction. The story is also well told, even if the author's understanding of space travel is, well, quaint.
The science - and the distances traveled - are not aspects of "The Planet Strappers" that bear thinking about, but Gallun's talent as a writer overcomes this shortcoming. Yes, some of the chapters near the end had me rolling my eyes, but I remained invested in the protagonist, and I wanted him to find peace. This sort of investment is hard to come by, and I was happy to find a lot to like in this book.