ship drift

[Babellon]

I am flying my Krait mkII around a planet. altitude 1000m heading 90 degrees [east]. Every few minutes my heading drifts left 1 degree and I'm curious to know why this is. Shouldn't I be able to set my heading to a certain degree and let it fly? I understand gravity pulling me down if its strong enough, I understand my elevation changing due to elevation of ground formations, but what factor would be making my ship drift 1 degree off mark every few minutes? At 66kph ( I assume thats the right way to state my speed), normal flight speed around the planet, will my ship turn around on its own and fly the opposite direction at some point? its a sphere shouldn't I be flying 90 degrees due east all the way around the planet?

 

[HAMM3R]

If you're referring to the ship's speed indicator saying 66, that's in Meters Per Second. 66 meters per second is roughly 240 kph or 150mph.

As to the drifting, I assume it's pretty difficult to keep it pointing directly in one direction manually. A tiny 0.2 degree deviation from the course at given location will translate to a lot more later on. Or maybe your controller isn't centering completely but keeps giving tiny steering inputs, if you're using an analog controller that is.

 

[Robert Maynard]

Unless you are travelling at a heading of 90° at the equator the heading will change - due to the fact that the ship will follow a great circle.

 

[varonica]

I am flying my Krait mkII around a planet. altitude 1000m heading 90 degrees [east]. Every few minutes my heading drifts left 1 degree and I'm curious to know why this is. Shouldn't I be able to set my heading to a certain degree and let it fly? I understand gravity pulling me down if its strong enough, I understand my elevation changing due to elevation of ground formations, but what factor would be making my ship drift 1 degree off mark every few minutes? At 66kph ( I assume thats the right way to state my speed), normal flight speed around the planet, will my ship turn around on its own and fly the opposite direction at some point? its a sphere shouldn't I be flying 90 degrees due east all the way around the planet?

Because the planet is spherical and rotating and it's likely you aren't exactly on the equator, I am guessing you are north of the equator, so coriolis force will push you off course;

an effect whereby a mass moving in a rotating system experiences a force (the Coriolis force ) acting perpendicular to the direction of motion and to the axis of rotation. On the earth, the effect tends to deflect moving objects to the right in the northern hemisphere and to the left in the southern and is important in the formation of cyclonic weather systems.

 

[RamirezKurita]

Heading straight East only works if you are flying around the equator, otherwise your bearing (the direction to the North pole) will change over time. It's not your direction of travel that is changing, it's the direction North from your location that is changing. Look up the concept of great circles in aerial navigation, as they are widely used for planning real-life flight paths for aircraft.

There's also the Coriolis effect to consider too, as the planetary rotation can knock otherwise straight lines off course unless you are heading straight east or west.

 

[IPFreely]

Being that a planet or moon is "round", your drift will increase due to travel because the horizon slips 1 degree lower for each 100Km traveled - more or less- depending on the size of that particular body. There is no orbital control for ships - corrections need to be made manually - This is especially noticeable when using coordinates instead of targeted points -