"Star Trek: Voyager" was developed in 1994 to add more traditional star trekking to the franchise. The show creators wanted a female captain for the U.S.S. Voyager, leading to the creation of Captain Kathryn Janeway. Kate Mulgrew was eventually cast in the role after Geneviève Bujold quit after two days of filming. Susan Gibney, who had previously appeared in "Star Trek: The Next Generation," was also considered for the role but ultimately lost out to Mulgrew. Gibney felt she was given the runaround during the audition process, with strategic selections of other actresses to make her look better.
Source: https://www.slashfilm.com/1739924/star-trek-guest-actor-susan-gibney-captain-janeway-before-kate-mulgrew/