How do I make my player run in rings up and down a "planet"?

Hey everyone,

I currently have a player character who can stand upright on the nearest “planet”, abide by its gravity and run around on its surface.
The movement is driven by adding impulse to the forward vector. This has the unfortunate side effect of making the controls feel random and clunky as the player is not always facing the direction you need to be facing when running and rotating around a sphere.
I have conceptualized how I think the movement should work, with the W/S keys moving the player solely up and down in rings on the planet’s surface, and the A/D keys left and right, however I am mathematically ignorant and am having a hard time figuring out how to bring this to life. The closest math I can find is of sphere points and sphere segments but I’m unsure of how to apply what I’ve read.

Am I missing an obvious solution? Overthinking? Is there a simple equation that I can apply here with blueprints?

TL;DR How do I make my player run in rings up and down a sphere?