If you’re watching science fiction movies, you might think that flying a spaceship is like driving a slightly more complicated car (or a Winnebago for that matter). Space balls). And George Lucas gave us these galactic battles with pilots who look like they’re flying fighter jets on Earth.
Well, the bad news: space is really, really different. In particular, moving a vehicle in orbit around the Earth is much more complicated. Maneuvers you can perform in an airplane sometimes have the opposite effect in orbit.
To understand what I mean, we’ll first dive into some basic physics and build a little model of orbital mechanics, then run some frigid simulations of an attempted docking maneuver. Read on!
Circular orbits
Imagine flying in a circular orbit around the Earth. To understand this type of motion, we need three main concepts in physics. First, centripetal acceleration. Recall that acceleration is a measure of how quickly an object’s speed changes.
But speed is not just speed, it is speed in particular direction— in other words, it’s a vector. If an object moves in a circle, its direction is constantly changing, which means it is constantly accelerating even if its speed is constant!
The direction of this acceleration is towards the center of the circle. (“Centripetal” means directed towards the center.) The magnitude of the acceleration depends both on the magnitude of the velocity (v), i.e. speed and radius (R) wheels. This gives the following equation:
Courtesy of Rhett Allen