(written from a Production point of view)
Joseph Will (born 4 November 1970; age 42) is the actor who appeared in two Star Trek: Voyager episodes. For Star Trek: Enterprise, he auditioned for the role of Charles Tucker III. It was down to the final two, between him and Connor Trinneer, and Trinneer ended up getting the role. He was brought back, though, in the character of Michael Rostov (another engineer) in three episodes of Enterprise. His costume from the episode "Muse" was sold off on the It's A Wrap! sale and auction on eBay. 
In addition to his roles in the two Star Trek TV series, Will also played the part of the chief security officer in Star Trek: The Experience - Borg Invasion 4D.