Create an account on CreateSpace to publish your science fiction book (if you do not already have one). You will register your email address, name, and country to create an account. You will need to create a password and let them know what type of item you wish to publish, which is a book.
Submit the information about your science fiction book. Enter the category, which will be Science Fiction, the title of your book, and your (the author's) name. Enter any additional information, such as description of the book, volume number, whether or not you want colored pages, and the size of the pages. Upload a PDF copy of your story and choose a cover design. Either upload your own cover design or choose one they offer. You can also add a photo to their free covers, to give it a more Science Fiction affect.
Wait for them to review your science fiction book. This usually only takes a day or two. They will not edit it but will verify that it doesn't contain things that are illegal.
Order a proof copy of your science fiction book. You will be required to review the book before they will sell it through Amazon.
Distribute your book. Once you've approved your science fiction book, you can place a price on your book and distribute it through Amazon. CreateSpace does take a percentage of the list price, plus a fixed charge. Some books may also have a per-page charge.