Ready Jet Go! Wikia
Ready Jet Go! Wikia

"Let's be scientific about this."


Sean Rafferty is a main character and one of Jet's best friends in Ready Jet Go!.


Sean, the son of a scientist, figures he’s going to grow up to be a great scientist himself and plans to lead the first mission to Mars. But he's afraid of heights, fears cramped spaces, and easily gets space-sick - things he's trying to overcome before he grows up and becomes an actual astronaut.

Sean’s the practical one, always insisting on doing things the old-fashioned way – even though he’s now suddenly hanging out in a very sci-fi reality with Jet! Sean’s a big fan of following the rules of the Scientific Method, which he sings about in his own song.

Sean is initially bad at using his imagination and afraid of going to space, but these lessen over time, such as in "Sean's Year In Space", where Sean pretends to spend a day (he originally intended it as a year) in space in the treehouse, and in Not a Sound, where he actually suggests going to space to prove that there's no sound there. He sometimes even acknowledges it by calling himself "Mr. Adventure".

At times, Sean can be a bit of a perfectionist. The most defining example would be in Eye in the Sky, where he has a chart for every single situation he could possibly end up in.


Sean is a young boy with fair skin and freckles. He has messy light brown hair, which, due to animation errors, can sometimes appear as blonde. Sean's regular outfit is a white shirt with a light green collar and sleeves. He wears blue jeans and brown sneakers. Due to inconsistencies, his eye color is either grey, blue, or green (most commonly blue).


In Project Pluto, Dr. Rafferty says that Sean used to carry a little purple hippo everywhere when he was four, much to his embarrassment. In Solar Power Rover, Sean claims that he doesn't have an actual pet, but in The Mindysphere and Sean's Neptune Tune, he says that he has a pet hamster named Pedro. Perhaps that during that timeframe, he actually got a pet.

Songs Sung

International Voices

  • Finland: Katja Sirkiä
  • Hungary: István Baráth
  • Norway: Oscar Stålhand Arnø
  • Latin America:
  • South Korea: Hong Bum-gi


  • Sean loves to use the Scientific Method to solve problems. He also tends to sing about it.
  • It is unknown where his father is; the only evidence proving he exists is a photograph spotted in Sean's Year in Space. He was mentioned by Sean in Night of a Bazillion Stars,
  • Sean is unathletic, as he was unable to do push-ups in "Sean's Year in Space". However, he did a perfect somersault in Back to Bortron 7.
  • Although it's said that he gets space-sick easily, he's only been space-sick in a select few episodes; these episodes being Tour of the Solar System, Tiny Blue Dot, Jet's First Halloween, The Mindysphere, Astronaut Ellen Ochoa!, and One Small Step. He was also shown being motion-sick in Jet's Time Machine. In I Feel the Earth Move, he reveals that he also gets seasick, as boats make him queasy.
  • He is claustrophobic and acrophobic.
  • Sean loves pot roast. At his house, they often have “pot roast night” for dinner.
  • In Whole Lotta Shakin', he says that he eats when he is stressed.
  • In Holidays in Boxwood Terrace, Sean is revealed to have an excellent singing voice. And he reveals that he likes to sing in the shower. However, later in the special, he gets stage fright when he has to sing on stage.
  • As of second season, Jet loves to call him "Sean-zo".
  • He knows how to play the drums as shown in Potatoes on Mars.
  • In Magnet, PI, he is shown to know how to do magic tricks under the name "The Great Seanzo".
  • In Fact or Fiction?, he says his favorite flavor of ice cream is chocolate.
  • He often talks into a tape recorder, calling it "Astronaut's Log". He did this in episodes like The Mindysphere.
  • During the Takeoff! sequence, the same audio clip of his screaming is always used, even after William Ainscough was replaced.
  • In the Hungarian dub, he is voiced by István Baráth, who also voices Rubble in the Hungarian dub of PAW Patrol.
    • His Finnish voice actress is known for being the voice of Elsa in Frozen.
  • His hamster, Pedro, is possibly named for Pedro Duque, a Spanish astronaut and aeronautics engineer who serves as Minister of Science of the Government of Spain.
  • Sean strongly resembles Jake from Molly of Denali.
  • In Galileo, Galileo!he says that his heroes are Galileo Galilei, Neil Armstrong, Albert Einstein, Marie Curie, and Patti Smith.
  • Sean could have a crush on Jet since they are always close.
  • Sean may be Irish, because both "Sean" and "Rafferty" are names of Irish origin. He also shares his name with two famous Irish men, one a poet and one a radio host.
    • Sean means "God is gracious", which suits Sean because he is polite to others.
    • Rafferty means "one who will prosper", which suits the Rafferty family as a whole because Sean's mother, Dr. Rafferty, is an accomplished scientist.
  • His name in the Norwegian dub is Lars.


Click here to view the image gallery for Sean Rafferty.
Click here to view the gallery.

Main characters
Jet PropulsionSean RaffertySydney SkelleyMindy MelendezSunspot PropulsionCarrot PropulsionCelery PropulsionFace 9000
Supporting characters
Dr. RaffertyDr. BergsAmy SkelleyMr. PetersonMitchell PetersonLillian

Uncle ZucchiniEggplantZerkFace 9001Moonbeam

Earth Animals & Robots:
CodyFloydJet 2 (character)Sydney 2 (character)BeepBoop