Lieutenant Garth- a friend of April's from Starfleet Academy, Garth will be a little envious of April gaining a command before he did. April will meet with his best friend Garth every time the Yorktown makes a stop over on Earth, or whenver Garth's ship, the USS Republic, is near the Yorktown.
Skon- Skon is the Vulcan commander of a competing freighter with the Yorktown that shares the same route. He will often be arrogant and a little proud, despite his supposed lack of emotion. His ship will save April's a time or two, and April and Skon will have a growing comraderie, if not friendship.
The Axanar General- This unnamed Axanar will patrol the borders of Axanar space, and often command boarding checks before allowing the SS Yorktown to enter Axanar space, which they often do on their freight runs. There will be a growing conflict between the Federation and the Axanar and this will cause tension, especially after April is put in command of the Yorktown.