— Jet Propulsion's catchphrase

Jet Propulsion is the main character of Ready Jet Go!. He is an alien from Bortron 7 who currently resides in Boxwood Terrace, Washington.


Jet may be a typical kid for Bortron 7, but he’s extraordinary to the kids next door. Always curious and fearless, he leaps before he looks. Jet is unafraid of failure - an idea there's no word for on Bortron 7 - and you can’t get him down. Like the Music Man, he might burst into a song he made up on the spot. He can build anything. Jet is endlessly delighted by our planet, which to him is huge and lush, incredibly varied and beautiful. He often points out the wonders of ordinary things to the Earth kids.

Being from Bortron 7, Jet is known to be perpetually cheerful and optimistic, a significant trait of his, passed down from his parents. Jet is cheerful, imaginative, and excited almost all the time.

Jet is also shown to be incredibly persistent, even having his own song about his well-noted perseverance, called the 'Try Again Ditty', knowing not of giving up, and also managing to convince Sean and Sydney to take him to the DSA in A Visit to the Planetarium.

Jet is really high-energy and loves to dance big time, also singing many songs throughout the series (his most complicated and noted ones are 'Night of a Bazillion Stars', 'So Many Moons', and 'The Milky Way').

His parents being intergalactic travel writers and being an alien, Jet inherits a vast knowledge on everything space, being able to perfectly name all the neighborhood stars and the moons of Jupiter, and is incredibly curious to learn more about it and even the Earth itself. Due to being an alien, Jet seems to be generally ignorant of some Earth slang/vocabulary, some traditional childhood activities, and other Earth traditions.

One major trait about him is his caring and kind personality. Bortronians are shown to be perpetually cheerful and optimistic, and almost never get upset, so this plays a big part in Jet's personality. Jet cares a lot for the feelings of others. In Night of a Bazillion Stars, he immediately apologizes to Sean after he breaks his telescope. Jet also seems to be very social, not being shy at all when he first met Sean, Sydney, and Mindy, and instead being very upbeat. Jet has a desire to be friends with everyone, and seems to have no enemies. He is even nice to Mitchell Peterson (who wants to expose his identity), despite Mitchell's animosity towards him.

Another large trait of his is his recklessness and spontaneity. While his friend Sean has an all-consuming drive for scientific fact and nothing but the facts (as well as an obsession of using the scientific method), Jet is often spontaneous in his space study.

Jet is unafraid of failure and will always keep going strong. Despite his tenacity, Jet is also shown to be somewhat quirky. Jet is shown to be forgetful, often forgetting the scientific method, and he even forgets that he has to keep his alien identity a secret, which annoys Sean, Sydney, and Mindy. Nonetheless, Jet is one of the more popular kids and Sean, Sydney and Mindy appreciate him.


Since Jet was a baby, he has been traveling all over space with his parents. One time, when the Propulsions downloaded the then-new version of the saucer dashboard software, everything went out of whack, and caused baby Jet to cry. Luckily, Sunspot cheered him up.

It is unknown how old Jet is in Earth years, but he is 63 in Bortronian years. In his 'preteen' years, his family left their Bortron 7 home to live on Earth to study it's customs. There, Jet met Sean, Sydney, and Mindy, who would become his friends. As revealed in Satellite Selfie, this happened in the summer.

Songs Sung


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Jet without his jacket on

Jet, like most other Bortronians, has fair skin, and spiky red hair (a possible reference to the theory that red-heads are aliens). He has gray eyes. Unlike the Earth children, whose faces are noticeably round, Jet's face is noticeably thinner. Like his parents, he wears a blue puffy jacket (which he almost never takes off, despite the temperature). He has a black utility belt with a grey buckle, blue pants, and grey boots with red laces.

In Mars Rock For Mom, Jet is shown to wear a white shirt with the Deep Space Array logo on it underneath his jacket.


  • Unlike the other children, he is voiced by an adult.
    • His voice is also provided by a female, but his voice actor sounded much masculine due to her vocal career in "Hey, Ocean!".
  • He was named after the Jet Propulsion Laboratory.
  • Like other Bortronians, he can stretch his body, learn (or 'download' any language & most likely has super hearing (in Just The Right Distance From The Sun, Celery mentions that Bortronians have super hearing))
  • Jet apparently has a device to contact Face 9000, as shown in one episode where Jet asks if he accidentally pocket dialed Face.
  • In Mindy's Weather Report, Jet reveals that he hates ice cream. This is also shown in Asteroid Patrol, Detective Mindy, Commander Mom, Asteroid Belt Space RaceTry and Try Again, and Fact or Fiction?, making it somewhat of a running gag.
  • The series was originally going to be named after him.
  • Jet appears to have somewhat of a crush on Dr. Rafferty, who is Sean's mom, as shown in some episodes. However, this went away in later episodes.
  • Jet has a wristwatch which he uses to communicate with his relatives on Bortron 7, or he can give it to Mindy to communicate with the gang when they're in space.
  • Jet and his cousin Zerk are the only members of the Propulsion family who don't have a vegetable name.
  • He and Zerk are also the only two characters in the show whose voice actors are the opposite gender as them (they are both voiced by women).
  • Jet can apparently speak rover & is able to communicate with Beep and Boop perfectly.
  • Jet is an expert mechanic, shown when he built Jet 2 in the episode of the same name, made a anti-gravity bracelet for Mindy, made a kart for the derby, & was able to repair Sean's telescope. He was also to repair the satellite in What's a Satellite?
  • Jet seems to have a 'musical motif'. He is shown to love singing & dancing, & had even managed to perform many complicated songs.
  • He is voiced by Ashleigh Ball, who's known for her best voice of Rainbow Dash and Applejack from the popular TV series My Little Pony: Friendship Is Magic and Plum Pudding from Strawberry Shortcake: Berry Bitty Adventures.
  • He is the lead singer of the band as shown in Potatoes on Mars.
  • He and Sunspot are the only characters to appear in every episode of the series.
  • Discounting the theme song, Jet was the first character to speak in an episode; the line was "Okay, new Earth game. I call it: Solar System!", spoken in Tour of the Solar System.
  • His name was featured in eight episode titles: Jet 2 (episode), Jet Cooks Dinner, Jet's Time Machine, Jet's First Halloween, Jet Can't Sleep, My Fair Jet, Jet Shrinks the Kids, and That's One Gigantic Pumpkin, Jet Propulsion!
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  • In June 2020, in response to a fan asking if Jet was bisexual, Craig Bartlett confirmed that all Bortronians are technically non-binary, although some may present as male or female. However, its unknown if Bartlett confirmed that Jet is attracted to both boys and girls, or if he misinterpreted the fan's comment and insinuated that Jet is both masculine and feminine.


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

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