Every good sci-fi story has to have a little action. You build the tension between characters up to a certain point, and then you put them against each other with blaster pistols, laser guns, what have you. But once in a while, all the weapons get thrown down and the characters just end up beating at each other with fists.
Practice the art of envisioning and writing a fight scene between two unarmed combatants. It’s a little more difficult than it sounds, but if you can do it right it can make make the difference between a so-so fight scene and an awesome fight scene. Give it a try!