To "System Era"
I just read you are implementing jet packs. Here's my thoughts on the dynamics.
This should be a combination of two elements, a thruster engine (a vertical only "Jumper") and an oxygen based control thruster (directional).
The Oxygen based thruster would provide the ability to hover and a directionally controlled fall. This should just be a nozzle add-on, but would consume oxygen at a rate not advisable without tanks. This could be available early on in the game.
The "Verical Jump Engine" would provide brief vertical lift in two versions. The early version would have a set number of charges with only a digital control (On/OFF). Say 5 or 10 bursts that will only take you so far, depending on gravity. The later version would have an analog control (speed controlled assent) that would deplete like an oxygen tank and would have a time limit for temperature reasons. Maybe even exploding if it gets too hot. Little animated dangers like this make it more fun. How far can you push it may depend on the planet's ambient temperature. The later version would also save on oxygen because you could use it to control descent , although not directionally.
Thank you for your time