You can get United Moon Colonies in multiple formats. Here's the list. All formats, paid or not, are Creative Commons Attribution-Noncommercial-Share Alike 3.0.
Print Book ($11.92)
Google Play ($5.00)
EPUB (Free - Thanks to Nicolas Kowal for the formatting. Cover by Sean)
.MOBI (Free - Thanks to Nicolas Kowal for the formatting. Cover by Sean.)
Full Text (Free)