Screenwriting : Screen writing a sci-fi by Remie Senyonjo

Imagine the story but research plausible science to base it on. For me I like to know that the Enterprise or Millenium Falcon could possibly exist in my lifetime or at least the science is been worked on. It makes it more exciting that humans can have ships like that rather than knowing a ship like that will never be made.

Start with a science tact then stretch it. That makes it plausible for the audience.

Just be consistent and make sure the science solves a problem for the people using it. All products solve a problem. If they don't solve a problem they don't sell and never survive.

Also make the interfaces super easy to use. No one is getting an implant in their head to make it easy to read email (for example). The movie HER did tech great.

Hmmm...Good question...Normally, I'd say knowledge, but for some reason when it comes to the sci-fi genre, I tend to not mainly give focus to known facts. My opinion is when it comes to that genre, it gives bias to imagination, it give you the opportunity to go outside the box. Create whatever world you may like, let your imagination run wild, but...just let it make sense at the end of it, in terms of the world you've created. Be consistent with the logic you've created for that world.

A good story first, an interesting problem, characters the audience can identity with, then advanced scientific structure that borders on magic.

Yes. All sci-fi is based on things, events, and concepts we already have (Starship Enterprise is a space submarine, a lightsaber is an energy katana, etc). Take some simple concepts and play with them. Hopefully you get some good results.

The Martian - it's MacGyver in Mars. But all the science of the movie is believable.

Have a clear knowledge of the science upon which the story is based. Some research may be required. Do as much as you need. Then as you dive into the fiction, establish clear rules of the game and apply those consistently. ROG examples: Aliens breathe nitrogen, the evil computer detects psychic fears, smells pheremones. Stuff like that.

All that is said and think about:

Asimov - science (fiction)

Vance - Fantasy

But all science fiction books/screenplays really are a 'combination' of science (kowledge) and fiction/fantasy, as others here already indicated. For me it's about creating an unique world; think Jack Vance "Tschai" or "Game of Thrones" and put in some original and believable technology to pimp up the story/scenes.