Shogoth, I usually miss most wonders as well, and tend to have empires the same size as yours (or a little bigger) when going for space. It's always a help when all of the civs are around to further accelerate the research rate, since it's rarely slower than when the human is leading it. That said, the only way I can see myself knocking a century off my own mark is by getting a faster start. My last two games have been domination ones, but I reached the middle ages by 270 BC in one of them, thanks to an aggressive starting strategy: four cities with barracks, and off to engage in serial war, stopping each quickly enough to pick up tech and not totally wipe out the civ. If I can get off to as good a start in a space-race game, I might have a chance.