UNSF: Reunion
Captain Darryl Mansel was perhaps one of the youngest and most qualified starship captains that the United Nations Space Force ever had.  Not that he regretted being young, though, most of his friends had been older than him all his life.  He was used to being young.  He took command of the U.S.S. Explorer in 2185, during the Imperial war.

For five years, Mansel and the crew of the
Explorer had battled-- Imperials, kidnappers, holograms, Marauder and Anarcha, smugglers...the crew had battled them all.  Throughout, Mansel had been in the forefront, always in command; his peers and senior officers thought highly of him.

In 2190, the half-man/half-machine species known as Borg had crossed universes and attacked the UNSF.  Forced to team up with the Imperials, Mansel and the UNSF beat back this destructive force and destroyed the Borg cube.  During the final battle, Mansel's ship, the
Explorer, was badly damaged and forced to stand down from duty.

As the crew of the
Explorer were assigned to different places, UNSF engineers designed the Galaxy class Explorer-A, under the command of former UNSF Intelligence agent Matt Vaughn.  Mansel became the Task Force Commander for 4th fleet, the fleet the Explorer had been under; the same fleet the legendary USS Stealthlon was also under.  For three years, Mansel directed the 4th fleet , telling them where and when to go and what to do when they got there.

Hearing of the new
Sovereign class vessels being built, Mansel (who was still a Captain) put in a request to command a ship; his request was granted.

This new ship Mansel commanded was named
U.S.S. Explorer-B.  Mansel requested his whole crew back, and got the vast majority of them.
                                                     --History of the Second Earth, Volume I