Tycho Hashoone: Twelve years old when the Jupiter Pirates series begins, Tycho is a midshipman aboard the Shadow Comet, and typically handles navigation and communications. The bane of Tycho's existence? Piloting. Well, that and math homework. Tycho finds himself caught between wanting to uphold his family's traditions and wondering if they're still right for him.
Yana Hashoone: Tycho's twin sister, twelve-year-old Yana typically handles sensors as a midshipman aboard the Comet. Quick-witted and fast-talking, Yana is brash and sometimes even reckless - a throwback to the Hashoones of pirate days. Where Tycho likes to quietly figure out the hidden connections between people, Yana favors more direct and even dangerous action.
Carlo Hashoone: Sixteen-year-old Carlo is the older brother of Tycho and Yana. Though a midshipman like his siblings, Carlo has more experience as a member of the bridge crew, and is already known for his skill as a pilot. Carlo honors the traditions of the Jupiter pirates, but has no use for nostalgia about bygone eras. He is confident that he will succeed Diocletia as the Comet's next captain - too confident for his siblings' liking and, perhaps, for his own good.
Diocletia Hashoone: The captain of the Shadow Comet, Diocletia is increasingly worn down by the burdens of keeping her ship and her family safe in a dangerous solar system. As keeper of the Log, she will determine which of her children inherits the Comet's helm, succeeding her as captain. Will she choose Carlo, Tycho, or Yana?
Mavry Malone: The Comet's first mate and father of Carlo, Tycho and Yana, Mavry is always ready with a quip to lighten the mood. But beneath his ever-present smile, he's a veteran privateer who's deadly behind the controls of a starship or with a blaster in his hand.
Huff Hashoone: The former captain of the Comet, Huff was nearly killed at the Battle of 624 Hektor, with half his body replaced by cybernetic parts. Unable to continue as captain, he passed the Comet's helm on to his daughter Diocletia. An old-school pirate, Huff is impatient with the restrictions placed on the Hashoones in their new careers as legal privateers, and dreams of a day when the old family traditions will be followed anew.
Carina Hashoone: Diocletia's sister, Carina was in line to succeed Huff as captain of the Comet. But after enduring tragedy at 624 Hektor, she vowed never to go into space again. Carina now lives at Darklands, the Hashoone family compound on the moon Callisto. From there, she helps run the family business and represents the Hashoones in their dealings with the Jovian Union.
Vesuvia: An artificial intelligence program, Vesuvia serves as an intermediary between the Hashoones and the computers that control the Shadow Comet. She can calculate a solution to any problem you throw at her, but gets very upset if you haven't done your math homework.
The Shadow Comet: The Hashoones' family starship, the Comet has plied the spaceways for centuries, first as a pirate ship and now as a legal privateer. A modified frigate, she is fast and well-armed, and many of her crewers come from families that have served the Hashoones for generations.