Basic Rocketry
From Kerbal Space Program Wiki
Basic Rocketry is the second node on the technology tree, and the only stage 2 node on the tree. This is the first node the player researches. It costs 5 Science, and includes four parts, including the first decoupler. This allows the player to build proper multi-stage rockets without having to resort to explosive decoupling.
This tech node also includes the first science experiment.
Required Research
As this is the first node the player researches, it only requires the one node the player starts with:
Available Research
Three nodes branch off of this one on the tree:
