I've often thought that it's just as important to be accurate with settings in futuristic fiction as it is in historical fiction. Even though the setting may exist only in the author's mind, there are some laws of science that must be obeyed to support readers in suspending their disbelief of the fantastic terrains, cultures, and people.
If you are writing science fiction, there are some questions you should ask yourself. Even if detailed answers never wind up in your stories, they should be clearly formed in your mind. Have you designed a believable planet, space station, galaxy, or alternate universe? Do your alien civilizations and ecosystems show a logical development over eons? Is your future technology based on immutable laws of physics?
Don't be swayed by some of the outrageous (albeit entertaining) characters you see in movies and comics. If you are writing science fiction, be sure you can explain why your hero's skin is able to repel projectiles, yet it can regulate body temperature, perspiration, and respiration. And give some thought to why your giant creature isn't leaving a crater with each step.
Unknown principles of science will surely be discovered in the future. So, there is nothing wrong with creating devices beyond the science we know. But your creations are more likely to be plausible, if they are handled consistently and are not just plain wrong. For example, if you are writing about creatures on Earth's moon, be sure that these creatures are (somehow) existing in the actual gravity, atmosphere, temperatures, and rotation of our moon.
So, be prepared to do research, regardless of what you write. Take your pick--history or science?