YWriter is a free word processor designed specifically for novelists and authors in general. It won’t write the thing for you, but it does help you chop your opus up into chunks to make it easier to manage. The program also provides tools to manage characters, scenes, goals and timelines, which are the bits which often get in the way of your creativity.
The Australian software developer, Simon Haynes, is also a published author of space opera, so if you want to help support his work, go download a free ebook version of the original title in his Hal Spacejock series from Penguin.
Of course, you can’t just write a bunch of unrelated scenes. You need an overall design goal … your plot. yWriter will generate a number of different reports from your scene and chapter summaries, from a brief scene list to a comprehensive synopsis. If you update the ‘readiness’ setting for each scene it will even generate a work schedule showing what you have to do to meet your deadline for the outline, first draft, first edit and second edit.