There are 9 standard probe classes, primarily these classifications apply to Federation / Starfleet but civilian organizations as well as some governments use the same (or similar) classifications. These classifications apply to Solas Tempus / the Serenity Concord.
Class 5 - Medium Range Reconnaissance Probe
This is a medium-range reconnaissance probe, with extended passive data-gathering and recording systems. The probe has a full autonomous mission execution and return system and is capable of atmosphere entry and soft landing. It is coated for low observability and may be modified for tactical missions with a custom sensor countermeasure package.