Mankind cannot violate the laws of nature, but engineering will eventually find ways to make maximum use of them up to whatever limits they impose. Those are the two core principles that define the technologies I speculate about in the Free Mars Defence Force Series. They, along with my firm belief that humankind will never truly rise above its base instincts to be tribal, selfish, and violent at times, guide the storyline.
It seems impossible to exceed the speed of light, and we have no idea about how to control gravity. While I love almost all science fiction including movies like Star Wars and Star Trek, and fiction books like Jack Campbell’s Lost Fleet series, all those stories have two features I think are unrealistic. First, spaceships in them routinely travel light years in only days. Second, often not even explicitly noted, their technology somehow controls gravity with perfection. Spacecraft accelerate forward, often at prodigious rates, while inside gravity is perpendicular to that acceleration, and nearly always just one Gee.
What would a future in space look like if you stuck with real science? While exceeding the speed of light and controlling gravity make for good drama and adventure, they make for disturbing (at least to me) science, and thus, unrealistic fiction. At present our science has no understanding of any way one could practically exceed the speed of light, Miguel Alcubierre notwithstanding. Nor do we have any idea if gravity can even be controlled, much less a clue about how that might be done. Taking nothing away from those great adventures, I wrote First Touch and its sequels because I wanted to look at a plausible real future. Everything in these books has a basis in our science today, but I allow engineering progress to take hydrogen and higher element fusion power, laser weapons, material sciences, and many other aspects of our science to the maximum that nature will allow. That’s what engineering always does.
That, and a firm belief humankind will not change, guides my stories.