From a production standpoint, Seven of Nine (Jeri Ryan) was brought in to the Star Trek: Voyager cast to increase the show's flagging ratings, but she also had actual responsibilities on board the USS Voyager. Seven wasn't required to have a defined role because she wasn't actually in Starfleet at the time and held no rank on the USS Voyager. But it was hard to overcome Seven of Nine's past as a Borg drone because the character fulfilled certain objectives in service of the Collective and needed to feel equally useful aboard the USS Voyager.
Instead of taking orders directly from Captain Kathryn Janeway (Kate Mulgrew), Seven of Nine acted more or less autonomously. While this didn't go over well with some of the other officers—namely Lieutenant B'Elanna Torres (Roxann Dawson)—Seven of Nine eventually learned how to work with other people. As part of the USS Voyager crew, Seven was valuable for the talents, skills, and knowledge that she had assimilated as part of the Borg Collective and still retained even after being severed from the Collective.
Seven Of Nine’s Duties On USS Voyager Explained
Seven Of Nine Was Essentially Voyager's Science Officer
In the broadest of strokes, Seven of Nine was the closest thing that Captain Janeway had to a dedicated Science Officer. Shortly after being severed from the Collective, Seven and Ensign Harry Kim (Garrett Wang) upgraded the USS Voyager with a new Astrometrics lab. Seven of Nine spent most of her time in Astrometrics, where she observed and analyzed data collected by Voyager's sensors. Seven's position in Astrometrics meant that she was often the first one to spot potential solutions, like the abandoned Hirogen communications relay that eventually connected Voyager with the Alpha Quadrant in Star Trek: Voyager season 4.
Because Seven of Nine operated under the Borg objective of efficiency, Seven undertook scientific projects that she believed would help the USS Voyager operate more smoothly, with or without approval from Janeway or Voyager's department heads. Seven's early ideas to make the USS Voyager work more like a Borg Cube put her in bad standing with Chief Engineer B'Elanna Torres, whether Seven's Engineering attempts succeeded or not. Ops Officer Harry Kim and the Doctor (Robert Picardo) were more open to Seven's suggestions, leading to the construction of Astrometrics and the medical use of Borg nanoprobes.
Seven Of Nine's Borg Knowledge Helped The USS Voyager Crew
Seven Replaced Neelix As Voyager's Delta Quadrant Guide
Seven's Delta Quadrant data was clinically filtered through a Borg lens of theoretically objective fact.
Being part of the Borg Collective at one point meant Seven of Nine had knowledge about the Delta Quadrant that Starfleet did not have. Information about potential resources and unfamiliar Delta Quadrant species, like Species 8472, was incredibly valuable. Once the USS Voyager reached a part of space that Neelix (Ethan Phillips) also wasn't familiar with, Seven of Nine became the crew's new unofficial guide through the Delta Quadrant. While Neelix based his information on a colorful combination of rumors and personal experience, Seven's Delta Quadrant data was clinically filtered through a Borg lens of theoretically objective fact.
