One of the great things about writing space adventures is getting to make up the world my characters inhabit. I create the whole shebang—the physical world (terrain, climate), type of government, culture, history, speech, religion even. I make all the rules. Well, not exactly all. To make the world believable, it all has to make sense. Take rules of physics like gravity, for instance. If the characters walk, what keeps them on the ground? If there is little or no gravity, their body shape would be different from ours. As our astronauts have discovered, in zero gravity they lose bone mass.
The terrain of a planet often determines the culture. A desolate planet can breed people whose very existence depends on their ability to find water, food, and shelter. They have to be strong (physically and mentally) or they die. They would govern with stern justice. Their deity wouldn't be a kinder, gentler god. On a planet lush with vegetation (moderate climate and adequate rainfall are a given) and plentiful wildlife, the necessities of life are easily attainable. Therefore, the inhabitants have time to develop creative arts, leisure time activities, technology. Those are two extreme. Other planets range somewhere in between. In Switched, I decided the early colonists on Serenia brought the technology to tame the harsh wilderness, including the ability to control weather, from their home planet.
Worldbuilding, according to Wikipedia, "is the process of constructing an imaginary world..." While much of the article refers to fantasy and science fiction as well as role-playing games, writers of all genres create the world their characters inhabit whether it's a fictional beach town, a Midwest farming community, a metropolis like Seattle, Detroit, or New York City, or a planet in another galaxy.
Just as some writers plot first, there are those who begin with worldbuilding. Before they put pen to paper (or fingers to the keyboard), they develop the whole world their characters will inhabit. One of the best guidelines comes from Patricia C. Wrede via Science Fiction & Fantasy Writers Association. If you Google "worldbuilding questions", you'll find many more sites.
I've mentioned before that I'm (sort of) a seat-of-the-pants writer. I get an idea and start writing. As I write, the world begins to develop in my mind. The hard part is transferring what's in my imagination to the written page. I have to make the reader "see" my world. Basic writing workshops emphasize using all the senses—seeing, hearing, smelling, tasting, touching. Writing about an imaginary place in an imaginary universe can be challenging. You can give "alien" names to foods but use common attributes like sweet, salty, bitter, etc. so the reader can identify with.
When I began Switched, I had no idea what all was involved in writing an adventure that took place off Earth. I learned in a hurry that I needed to keep track of the details. Just as eventually I have to plot, I had to develop those details in more, well, detail. Wrede's article hadn't been published yet so I was pretty much on my own. I read Stephen Gillett's World-Building and found many scientific details I hadn't thought of. Since hard science is not my thing, I also found a cure for insomnia.
When I was doing a little research for this post, I discovered so much more that's available for worldbuilding than I ever imagined. Besides questionnaires and checklists, did you know there is worldbuilding software? College courses on worldbuilding, including one from California State University, Los Angeles? A World Building Congress? With the popularity of role-playing games, I shouldn't have been surprised.
A writer could spend months, years even, building a world. But, of what use is that world without a story? According to Robert McKee in his book Story: Substance, Structure, Style and the Principles of Screenwriting, story is, well duh, what's important. The devil is in the details. But don't get so bogged down in the details that you forget the story. More importantly, leave the worldbuilding checklists/questions and write the story.
From my bio, this blog, and Switched, you can tell I'm enamored with Star Trek. I'd love to live in that world. What imaginary world would you like to live in?