I just started playing Mass Effect 3. It is a game that has the tag line "Take Earth Back" so I am not spoiling anything by saying that yes Earth gets invaded by aliens. Of course the forces of Earth fight back but as human forces tried to subdue the onslaught of invading forces I noticed something that you see a lot in scifi properties. A genuine lack of airforces. I know what your thinking but entertain me for a moment. Sure they had ships in the air fighting, but these were spaceships in atmosphere, not aircraft. And this makes a huge difference.
Now we have to get into some ideas about propulsion before we can explore this any further so to start I want to focus on scifi that uses conventional thrust for flight/space travel. So no matter how advanced the tech is in the story, I am talking about craft that travel using thrust. No weird anti gravity drives where the craft can travel like a flying carpet, in any direction at any moment.
So now that we have that established, my big concern is in regards to airplane design versus space ship design. Most space ships in scifi that can enter and travel in the atmosphere are not the most aerodynamic vehicles and they don't have to be. Flight in space without the presence of air allows vehicles to travel without resistance. Space craft, properly designed can 180 on a dime travel backwards on the same vector, because the physics of space allows it.
Now a lot of scifi vehicles that can go into the atmosphere would be the equivalent of falling bricks because they aren't designed aerodynamically. For space they don't need to and with differences in atmospheres between planets, an aerodynamic design that works on one world could be torn apart on another so the idea of explaining the flight into a planet's atmosphere and reentry using advanced tech is reasonable. But would these ships be the best option for defense? I think not. Most spaceships in an atmosphere would have to travel slowish compared to jet fighter planes, else wise the lack of aerodynamics would make flying fast an incredible danger. This is why I think an advanced airforce that can travel at tremendous speeds, would be a really effective defense and something that should be in more scifi. Sure they probably couldn't reasonably travel in space, but a scifi jet, accelerating forward at impossible Gs, crossing whole continents to deliver a payload of bombs to a target that can't react fast enough to even see it coming. Just a thought.
