Curious Droid (worth following!) recently posted a video about Evel Knievel but more importantly Robert Truax and his X-3 Volksrocket design which would have made Knievel the first private astronaut to reach space. Truax is most known for Sea Dragon and the Thor missile, so is no stranger to rocket engineering.
Why is this relevant? well, Truax although a professional worked out of his garage and put the X-3 together out of surplus rocket parts. Powered by four Rocketdyne LR101 engines the rocket would loft its single passenger to 62 miles and return them safely. Unfortunately, it never flew but was extensively tested and modified under a Navy contract for a sea-launched satellite launcher, designated X-3A.
The backyard engineering of this project is pretty amazing, and it is a pity it never made flight but others are following in the footsteps so stay tuned!