Two years ago, the sky exploded. A burst of bright light blinded Equestria as the heavens became pure, white radiance.
Two years and a day ago, the moon was decimated as something unknown collided with it.
Two years and two days ago, a message from the stars was sent to Equestria. Repeating for the duration of the day, the message was simple:

"Look up."

We aren't alone any more. There are things out there that we can't even comprehend.
And so we've sent our best up there, out among the stars, to find what they may.
They are the crew of the Space Shuttle Challenger. Their mission: To seek out the unknown, to protect Equestria, and to go where no pony has gone before.