Class-4 probe

A class-4 probe or more specifically class IV stellar encounter probe was a type of probe used by the Federation Starfleet in the 24th century.

The probes were essentially modified class-3 probes and had a range of 3.5x106 kilometers. They were powered by a vectored deuterium micro fusion engine with an expanded deuterium storage for maneuvering which could propel them at warp 0.6. They had triple-redundant particle- and field-detectors as well a a group of sensors for stellar atmosphere analysis. 

In addition to that, these probes had six launchable radiation flux sub-probes on board and was also usable for non-stellar energy-phenomena. They could only remain on a terrestrial planet for a limited amount of time.