Science Questions with Surprising Answers
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Dr. Christopher S. Baird

What kind of space ships can make banking turns?

Category: Space      Published: February 16, 2013

By: Christopher S. Baird, author of The Top 50 Science Questions with Surprising Answers and Assistant Professor of Physics at West Texas A&M University.

No kind of space ship can making banking turns in space. When an airplane makes a banking turn, it does so by deflecting off a cushion of air. The air redirects the plane's momentum in a new direction. In space, there is essentially no air, so space ships cannot make banking turns. In order for a space ship to turn, it has to fire a rocket sideways to reorient itself, then fire its main engines to begin traveling in this new direction. But because there is no air to redirect its momentum, a space ship still has momentum in the original direction. The result is a graceful, slow, arching turn. In order to get rid of its original momentum, a space ship would have to fire rockets in the opposite direction that it was originally traveling. The bottom line is that banking turns are not possible in space. Dogfights between enemy craft are only possible in the atmosphere - not in space. Hollywood tends to distort this principle of physics in order to make space battles more exciting, as well as to appeal to viewers who are accustomed to watching aerial dogfights that became the stuff of legends during World War II.

animation of space ship turning using rockets
A space ship turns by reorienting and then firing its engines in the desired direction as there is no air to bank off of. Public Domain Image, source: Christopher S. Baird.
animation of plane making banking turn
An airplane turns by banking off the air. The air simply redirects the momentum of the plane. For this reason, a plane can turn with its engines off. Public Domain Image, source: Christopher S. Baird.

 

Topics: air, banking turn, dogfight, space movie, space ship, space travel