After seeing quite a few questions asked about the empty Colossal Rocketry node, I decided to dig through CKAN to see what I could find (filtered Recommends, Suggests, OR Supports CommunityTechTree). The first one that popped out to me was:
Behemoth Aerospace Engineering Large Parts
Sure enough, installing this filled out that node. Hopefully that helps!
Note: the latest version the mod supports is 1.6.1.