Valakian shuttle

A Valakian shuttle

A Valakian shuttle was a small, pre-warp vessel used by the Valakians. In 2150, the Valakians launched four of these vessels to search for a cure for their plague by seeking help from more advanced species. The shuttle had propulsion modules located on the flanks of the hull above the wings, tapering inward towards the rear.

In 2151, Enterprise NX-01 discovered one such vessel drifting becalmed in space, its two occupants unconscious. (ENT: "Dear Doctor")

In the stage directions from the writers' first draft script of "Dear Doctor", this craft was described as "small". The same teleplay named the Valakian shuttle which Enterprise encounters as the "Sion" and Trip Tucker initially postulated that the craft might be a sleeper ship.
In the final draft of the "Dear Doctor" script, this vessel was instead described as "weathered." The script went on to explain, "It is similar in size to one of Enterprise's shuttles and has the appearance of something that might have come from Earth in the early 21st Century." Indeed, the shuttle resembles a 20th century Earth space shuttle, with wings at either side of the hull and a tailplane on the dorsal surface, suggesting that it could be flown into an atmosphere.