All probes shared the same general characteristics and differed only in equipment necessary for specific missions.

[3] Each probe also incorporated improvements based on experience with earlier missions.

Also mounted on the Orbital Compartment was a parabolic high-gain antenna, used for long-range communications.

Depending on the mission, the probe would carry specific instruments or a detachable landing module.

[3] Course correction capabilities were provided by a KDU-414 engine attached to the top of the Orbital Compartment.