How do direction work in space because north,east,west and south are bonded to earth? How does a spacecraft guide itself in the unending space?

Question

How do direction work in space because north,east,west and south are bonded to earth? How does a spacecraft guide itself in the unending space?

In: Physics

Answer 1

Ooh, I know this one. It’s called a [gimbal](https://en.m.wikipedia.org/wiki/Gimbal). The concept is used in [inertial navigation sysyems](https://en.m.wikipedia.org/wiki/Inertial_navigation_system). Basically, 3 gimbals provide your 3D reference (xyz) to orient yourself. The gimbals will always be spinning in the exact same orientation in space no matter how a spaceship flips and spins. There’s a scene in apollo 13 where they talk about [gimbal lock](https://en.m.wikipedia.org/wiki/Gimbal_lock), meaning they’re losing their ability to orient themselves because one of the gimbals is close to being “trapped” or “caught up” with another gimbal, losing orientation in that axis. [Here’s](https://youtu.be/OmCzZ-D8Wdk) a short video explaining it.

Edit: ~~Imagine two of the gimbals represent the xy-plane and its parallel with the Earth’s orbital plane around the sun. You can read the gimbals to tell you if you’re pointing “above” Earth’s plane of orbit or “below” Earth’s plane of orbit (assuming the North pole points “up” for us northern hemisphere dwellers).~~ I’m guessing, I shouldn’t do that.

More science related to gyroscopes and the relevant phenomenon with demonstrations you can see [here](https://youtu.be/XPUuF_dECVI?t=23m). See also 35:35 for another demo.

Edit: Silly me. Walter Lewin specifically talks about it in this video at 43:50. Watch that.

Edit: I’m an idiot. I’m talking about the gimbals like they’re spinning. They’re just the rings free to rotate and allow the central gyroscope to spin and maintain its initial position. Don’t trust everything anyone says.