Both Warren Ellis and Ken Hite have referenced the work of Charles Fort frequently. There's wacky stuff all over the Fortean Times website and almost all of it is excellent for gaming purposes.
For example, check out this article about a couple of Italian amateur radio operators who claimed to have recorded telemetry from Soviet and American spacecraft in the 50s and 60s. The trick with using stories like this for games is to turn off your critical faculties and ask, "What if it's true?". What would that mean? A secret Soviet space program has all sorts of possibilities.
Here's the money quote:
There are those who believe that somewhere in the vast blackness of space, about nine billion miles from the Sun, the first human is about to cross the boundary of our Solar System into interstellar space. His body, perfectly preserved, is frozen at –270 degrees C (–454ºF); his tiny capsule has been silently sailing away from the Earth at 18,000 mph (29,000km/h) for the last 45 years. He is the original lost cosmonaut, whose rocket went up and, instead of coming back down, just kept on going.
What if the cosmonaut is in suspended animation, waiting to wake up when a specific trigger is hit?
What if there's no cosmonaut at all? Maybe there's a payload of a different kind designed to deliver something to an extrasolar address. Maybe someone needs to send a message.
Maybe there's something so horrible and so indestructible that it had to be sent off-planet with extreme prejudice. Maybe there are more of them still here. Or maybe that was just the first one and others are on the way.
Or maybe, just to drop back to something slightly more mundane, the Soviets really did screw up and there's a corpse floating away from our star system. Is he the only one? Were there other, more successful launches from the USSR or any other country? Is there a vast city on the dark side of the moon? Is there a man-made structure orbiting the sun that we can't see because it's always on the other side?
OK, that became less mundane but you can see how far these ideas can be taken. If X is true, that leads to Y and Z. The weirdness level of your game depends on how far you want to go. Double-R, perhaps?