The app allows users to hear the Epcot Mission Space & Spaceship Earth & Magic Kingdom Space Mountain loops anywhere in the universe.
Actually, you'd need either 3G or wifi so, you probably can't leave earth, but I was in the middle of a "space thing".
The app does start up each time with a modified Main Street Electrical Parade intro (as heard on the podcast.)
Plus, like Dana, you can sleep to it and drift off to dreams of Briar Patches and Country Bears. Just set the timer:
It's in the iTunes store or find it online at subsonicradio.com.