Hi guys,
I'm a little bit rusty, but I do have a plan on how you can beat my previous launch date.
Step #1: Pick your opponents wisely. Against at least 2 other scientific civs on a single landmass type of map. Since the faster the AIs can research, the faster you can launch your spaceship. The Korean is usually a very fast researcher (scientific and commence = can't get any tougher than that) so they would make a perfect/tough opponent.
Step #2: As soon as you are capable of, go to war against one of the civ and expand your empire. Try to farm an army or two but do not load any units into it. Basically, you are just creating some army units in reserve for future warfare. Leave the Korean (or whatever civ that has the Great Library or will build the GL for you) alone.
Step #3: Now, sit back and build up your business and troops. You need at most 16 musketmans, but at least 75 cannons and 50 cavalry.
Step #4: Just sit back, relax, and wait until around 1200 or 1300 AD or whenever you think your researcher has reached the modern age.
Now, declare war and wait for them to come to you. IIRC, about half of their troops are obsoleted because they rarely upgrade, but you will surely go against tanks and mech infantry. Load up all your empty army units (in reserve) with musketmans or what the best defenders you have.
Step #5: Fight your war wisely and try not to get a lot of your units killed.
Hint: You should have known by now that your army units isn't for combat. Just dress up your armies in shinning armor with big horns and drums, their true purpose is to scare of the enemy and to protect your stack of cannons and cavalry (since the AI often go for other easy target first...). Btw, did you know that the Spanish sent 180 men and one cannon against eighty thousand Inca warriors. Of course, if the Incan attacked, the Spanish wouldn't have a chance, but the Spanish managed to conquer the entire Inca Empire with ease. Anyway, your cannons should be able to blast your invaders down to 1HP. Your cavalry should be able to finish them up without much of a problem. It will get easier if you have a couple of cavalry armies too, but you need to build at least one defending army first.
Step #6: Liberate the Great Library and build your space ship.
PS: If these tips work, you can thank AutomatedTeller. He was the one that asked me to post something here.