At the moment I am developing the landing gear for the spacecraft in the upcoming sfsim simulator.
The Jolt Physics library provides a great physics implementation for wheeled vehicles.
Previously I have implemented extracting a small part from the planet mesh and convert it to a Jolt Physics mesh.
This then can be used to simulate the behaviour of the suspension and the wheels when the gear makes contact with the ground.
I am also working on an animation for gear deployment.
Blender supports different constraints such as inverse kinematics as shown in Mark Alloway's tutorial.
Here is a video showing the first working version of the landing gear (doors not implemented yet).
Only part left to do is baking animations, exporting it to glTF and driving the animations using information from Jolt Physics.
Let me know if you have any comments or suggestions.
If you are interested in a realistic space flight simulator, please consider wishlisting sfsim on Steam.