The Physics of Space Battles

Last night I watched Star Wars IV: A New Hope and something jumped out at me. When the Rebel fighters are flying in to destroy the Death Star, all the X-Wing fighters move their wings into ‘attack position’, that is, they snap the wings out into the iconic X-shape. But since space lacks air or, for that matter, any other fluid in significant concentrations, what would the point of even having airfoils be? It seems to me that the wing configuration should be irrelevant to the maneuverability and speed of the vessel because there’s no fluid passing over them.

Joseph Shoer, a Ph. D. candidate in aerospace engineering who studies how modular spacecraft could be assembled has a fasincating piece on the topic over on Gizmodo. Turns out what I know about ships transfers, at least a little bit, to spaceships and I was right about the whole wings bit. From the article:

First, pending a major development in propulsion technology, combat spacecraft would likely get around the same way the Apollo spacecraft went to the Moon and back: with orbit changes effected by discrete main-engine burns. The only other major option is a propulsion system like ion engines or solar sails, which produce a very low amount of thrust over a very long time. However, the greater speed from burning a chemical, nuclear, or antimatter rocket in a single maneuver is likely a better tactical option. One implication of rocket propulsion is that there will be relatively long periods during which Newtonian physics govern the motions of dogfighting spacecraft, punctuated by relatively short periods of maneuvering. Another is that combat in orbit would be very different from combat in “deep space,” which is what you probably think of as how space combat should be – where a spacecraft thrusts one way, and then keeps going that way forever. No, around a planet, the tactical advantage in a battle would be determined by orbit dynamics: which ship is in a lower (and faster) orbit than which; who has a circular orbit and who has gone for an ellipse; relative rendezvous trajectories that look like winding spirals rather than straight lines.

The Physics of Space Battles [Gizmodo]


3 responses to “The Physics of Space Battles

  1. You’re absolutly right, but if we look for logic and scientific accuracy, we would lose a lot of cool features. For example, the size and proximity of planets in the scifi movies is a gravitational aberration. And for my part, I always thought the attack position was a tactical procedure for weapon use, but this is the story I told to myself.

  2. One thing to look at is the space battles as presented in the Battlestar Galactica Series (the newer ones) I think that the represent the truest application of Spacial Physics as applied to combat capable spacecraft.

  3. As I understood it, the order “Lock S-Foils in attack position” had nothing to do with the ships’ manoeuvring capabilities and everything to do with the placement of their cannon armament – on the wingtips. By opening out the wings the cannon are spread – which opens up new options for convergence of fire and indeed redundancy in the case of being hit. It is also worth considering that the X-Wing was intended to be able to operate under atmospheric conditions as well as in orbit or deep space, and the increased surface area of an X-shaped wing may provide stability benefits for a gun platform. If there are aileron equivalents on those wings they may also enhance atmospheric manoeuvrability.

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