A four-wheeled articulated steering vehicle for terrain exploration. The four-wheeled articulated steering vehicle has a pair of robotic tethered two-wheel vehicles that dock, lock, and drive long distances as the four-wheeled, articulated steering vehicle. Two actuated docking mechanisms attached on opposite ends of a central module of the four-wheeled vehicle enable “sit/stand” functionality. The “sit” configuration is achieved by aligning each dock mechanism parallel or nearly parallel to the surface, allowing two-wheel vehicle to detach and explore while the other remains docked and serves as a backup. While ‘sitting’, the central module rests on the ground and is outfitted with shovel-style wedges for passive anchoring. In order to “stand”, the exploring two-wheel vehicle reattaches, locks, and both dock mechanisms are rotated until each two-wheel vehicle's caster arm is upright and the central module is lifted off the ground. Once upright, each two-wheel vehicle rotates about a pivot point for articulated, all-wheel steering, which is accomplished by applying differential wheel torques.