Jack Baker was one of the lead pilots during the Robotech Expeditionary Force's voyage to Tirol and then back to Earth afterwards. He and Karen Penn held a complex relationship, somewhere between strong feeling of hate and admiration, much like that of Lisa Hayes and Rick Hunter before them. Baker, although holding a low rank at the start of the war, was essential in many of the early diplomatic relationships with other species, and quickly became one of the leading faces of the voyage and later war.