On his current mission, Don Pettit, the flight engineer for the International Space Station put together some stunning images of star streaks around the earth. His images give a surreal and artistic look at the beauty that can be seen just above the atmosphere. On the ISS's Flickr page, Don describes his process.
“My star trail images are made by taking a time exposure of about 10 to 15 minutes. However, with modern digital cameras, 30 seconds is about the longest exposure possible, due to electronic detector noise effectively snowing out the image. To achieve the longer exposures I do what many amateur astronomers do. I take multiple 30-second exposures, then ‘stack’ them using imaging software, thus producing the longer exposure.”