Thankfully, most pathfinding algorithms should be possible to implement in higher dimensions. Many of them work on node structure, which is agnostic to actual geometry.
Harder problem might be generating the dataset needed, unless your world happens to be voxel based (3d grid). You could try casting cube shapes via
intersect_shape (docs) at points of a rectangular grid to make a voxel representation of places rocket can or cannot go. Run astar or similiar algorithm then on this data. Performance/quality adjustments come from the fidelity of the voxel grid.