Shannon O'Donnel was an ancestor of Kathryn Janeway's and her greatest inspiration for joining Starfleet. She was also a consulting engineer on the Millennium Gate project that was completed in 2012 in Portage Creek, Indiana on Earth.
O'Donnel was an aerospace engineer and trained to be an astronaut with NASA. Her class came up with the slogan "Next stop... Mars", which was used by NASA's media department. Unfortunately, she did not make it through the training program, although her descendants would mistakenly remember her as a pioneer for those projects.
After leaving NASA, O'Donnel worked in the aerospace industry but eventually lost her job. She found herself unemployed and homeless and began traveling extensively, keeping a personal log by means of a small tape recorder as she did so. It was during this time that she made plans to visit a cousin of hers in Florida. Midway through her journey she found herself stranded when her station wagon broke down in the small town of Portage Creek, Indiana, where she met Henry Janeway.
Janeway was a resident of Portage Creek, the future home of the Millennium Gate, and owned a little bookstore, Alexandria Books. O'Donnel met Janeway in his bookstore which was the only store in town that had not closed in order to make way for construction of the immense project. Both Henry Janeway, and his son, Jason, were initially suspicious of O'Donnel but welcomed her nonetheless, and he even offered her a place to stay until her car was fixed.
The next day O'Donnel and Jason watched in front of the bookstore as Henry argued with Gerald Moss, who was being interviewed by Marci Collins of 3 Action News. The next day, as O'Donnel sat in a local bar planning her departure, Moss approached her.
Moss, who had worked at NASA at the same time as O'Donnel, told her that a classmate of hers made it into to the space program and was scheduled for four months of duty on the space station. Moss offered O'Donnel a job as a consulting engineer on the Millennium Gate project if she managed to convince Henry Janeway to give up his bookstore.
Because O'Donnel genuinely believed in some aspects of the project, she made several attempts to convince the classical-leaning Janeway to sell his store. Despite a mutual attraction, Janeway's resistance remained. Even though she failed to convince him to sell, Moss told her the project could still use her at the alternate building site of the Millennium Gate in Canton, Ohio.
When leaving town, O'Donnel realized that she did not want to leave Janeway and returned the same night. She talked to him and Janeway decided that he might re-open his bookstore in the Millennium Gate. Just before midnight December 31, 2000, O'Donnel and Janeway left the Alexandria Books bookstore, which then closed for the last time.
Eventually, Shannon O'Donnel married Henry Janeway and together they had several children and grandchildren and lived in Indiana.
Unknown to her, she became an inspiration for a distant relative fifteen generations later: Kathryn Janeway who heard about her in family gatherings. However, the facts about her life were greatly exaggerated; it was believed that O'Donnel was instrumental in building the Millennium Gate, one of the "first woman astronauts" and a participant in the early Mars projects.
Kathryn Janeway – with the help of Seven of Nine and Neelix – discovered her picture, as well that her role and who she was differed vastly from what she had believed all her life. However, Seven and others reminded her that historic facts were irrelevant, as Shannon was an inspiration for Janeway to pursue her dreams and therefore an important part of her history. (VOY: "11:59")
Shannon O'Donnel was played by Kate Mulgrew.
In the novels The Rise and Fall of Khan Noonien Singh, Volume One and Volume Two, Shannon O'Donnel works at Area 51 (aka the Groom Lake Facility) under the supervision of Jeff. She is described as "on loan" from NASA. After being contacted by Roberta Lincoln, she helps to create, and later steal, the first DY-100-class spacecraft.