Historical Progression Tech Tree This tech tree is designed to take you through the history of the human space program. I always felt like the stock tech tree was lacking and did not like the placement of the parts. There are other tech trees that utilize the stock tech tree and move parts around and that is what inspired me to create a new tech tree like this. The tree will start you with Unmanned parts before you progress to learning how to send Kerbals into Space safely. What I did