If the time it takes for politicians in the Union, more specifically their offices, to respond to correspondence is similar to the time it takes politicians in Canada to do so, I suspect it is too late to write for tickets.
I'd suggest calling their office directly. No need to mention anything about politics. Just say that you're a passionate supporter of about your nation's space program and would like the opportunity to watch the Space Shuttle lift-off in person before the program is over.
Ideally, perhaps you could also ask them to oppose any cuts to NASA and the human spaceflight program while you're on the phone? Since you're playing SSM2007, I suspect that you're against any potential cuts, plus it will further show your passionate support for the space program.
Even if you don't get tickets for this launch, it isn't too early to ask for tickets for the next launch, I suspect.
