I am about 2 turns to complete 2 SS engines, which was my last spaceship part. I researched every tech for space race.
My strategy:
Luoyang, Shanghai, Fuzhou(on stone), 4th city is Lu'er-dao(Kagoshima, Japan gold), and 5th Qingsen(Aomori, Japan silver). Oracle currency; research machinery and build the grand canal ASAP. 2 Japan city build nothing but workers and settlers (let'em flip when Jap spawns); conquer India about turn 160-170. Build Mauseleum of Mausollos (conquer Persia to get Z'ism), forget UHV #1 and you can get near-perpetual golden age.
If you are interested, try my savefile... I researched steel & railroad by 1150, Mongols are not even a threat. But when Mughal spawns, bug happened - they got no tech and no unit, only flipped Delhi and didn't flip their flip zone. This made my game less solid.
By the way, I got about +60 stability at military. Nobody is my match. It felt good when I massacred English & French trading company stacks with bomber, infantry and tanks.