The main character doesn't really know whats going on. HE really is just some random geek. He just happens to do something that significantly effect the future later. So I don't know where you got the Idea of him knowing more than that.

The only way it would make sense for him to do anything is if he is somehow involved with whats going on, otherwise no one would go to him for help. So the only way to keep it reasonable is if he some how has something to do with the grand scheme of things. To start it on a space station also would be strange. If we are dealing with normal people there isn't really a good reason for the space station, unless of course thats where they live, and its more of a colony than a space station. In which case it wouldn't really make a difference if it were on a planet or a space station.

Plus, it is a space station they would most likely detect the arrival with the space man, but that would have to change more aspects of the story thus far to make it fit. It makes much more sense to keep it on a planet in moder times to start. Now if you just want the space station to be an opening seen before you actually take control of the main character thats a different story. That can be easily worked in. However its one of those things that we'll work on when the overall plot and story is decided upon.

Your Idea's just don't seem to work so well when you try to put them together. Given what you've said it would cause to many bothersome uncertainties that would cause us to make some stretches to work in, even if we only used your Idea's and scrapped our current work.