Class 8 probe

From Memory Alpha, the free Star Trek reference.

A class-8 probe was usually instrumented heavily with sensor equipment, and was designed for extended flight at velocities up to warp 9. Class-8 probes were based on the photon torpedo spaceframe.

Though not specifically designed to transport a person, it was a class-8 probe in which Special Federation Envoy K'Ehleyr arrived on board the USS Enterprise-D on stardate 42901.3. On this stardate,the sensor equipment was replaced by a life support system, capable of sustaining one person. (TNG: "The Emissary")