Here’s a cross-section of the Jovian Luck.

The exact layout of components is hard to depict, because in an orbital craft there doesn’t necessarily have to be a ceiling or floor. Things could be located any surface. The Luck however was designed to land on gravitational bodies as large as Ganymede, and has a defined “vertical” axis.  These era skimmers are unique because they have engines mounted in opposing directions. The external engine mounts have hall thrusters that operate in orbit providing low thrust and high-specific impulse acceleration. This is very fuel efficient, accelerating for half the trip, then decelerating the second half (booster engines would be in the forward direction of travel on the first half of the trip, and the heat shield would be in the forward direction of travel on the latter half). The engine units themselves are capable of a 90 degree rotation for landing utilizing cold-gas thrusters. However, these thrusters do not provide enough thrust to overcome atmospheric drag, for which the ship has two inboard hybrid rocket engines. This is why older model skimmers are often considered to be flying “backwards”.