If you have access to a camera with manual exposure settings, here's an experiment: Setup the exposure for a properly exposed, sun lit daytime photo.

Without touching the settings, take the camera outside at night, point it at the sky, and snap a photo. What do you think you'll capture?

The answer is: nothing. The stars are far too dim, compared to sunlight, to show up in the exposure at all. Most space photography is done in sunlight, of things that are sun lit. The cameras are set to properly exposed these sun lit things, and the lack of an atmosphere doesn't change the fact that the stars are just too dim to show up in the same exposure.