SciFi Kiddie Lit Nostalgia

It's not just a rumor, I was reading scifi way back in elementary school. I remember buying this paperback at the school book fair in either third or fourth grade. Yes, the printing press had been invented about two weeks earlier. So. I had on my mind the last week or so that I had read this weird book way back when about two boys who built a spaceship and went on an outer space adventure. And then I found it had recently come back from out-of-print obscurity! It was originally published in 1954. I ask you, how could I help myself? I bought a copy. I'll read it after I return from Margaret Atwood's dystopian future. I'm still waiting for my flying car.