I doubt you will ever find a free website, but you will get a free domain (although they only cost $10 a year anyway) if you sign up for hosting with bluehost.com for 1 year, which costs $6.95 a month. They have free tools like forum software and wikis (you'd want the latter) that you and your techie helper* can set up and you'd be in business. godaddy.com is another good hosting company, but their site is so busy with crap, I hate having to go there to do anything. But they are comparable. Maybe you have UK companies that would be better?
*You should find someone in your sci fi world, which should be relatively easy, to help you out with details and maintenance.