Ready Jet Go!

• Jet Propulsion[6] (voiced by Ashleigh Ball)[7] is the title character of the show and is a humanoid alien. He has red hair and can stretch his body, as his parents can. He is excitable, energetic, and goofy. He is tall for his age. Jet is 63 years old in Bortronian years, as revealed in "Earthday Birthday". He was instantly popular with the other children the moment he arrived on Earth. He sees the mundane world as a vast and exciting place, and even thinks that words are exciting, such as "surprise", claiming it to be a funny Earth word. He is named after the Jet Propulsion Laboratory.[8] He is shown to be extremely kind, even to people who are mean to him, such as Mitchell. He possibly likes Sydney, because he danced with her in "How Come the Moon Changes Shape?", and is shown to possibly like Sean in "Back to Bortron 7".
• Sunspot[9] Propulsion[10] is the Propulsion family pet. He is described as a dog or cat to "Earthies" not in the know. Sunspot has the ears of a rabbit, the body of a kangaroo, and the tail of a raccoon or a fox. He plays concertina, electric guitar, bugle, pan pipes, and drums. Sunspot is silly and likes to play. His status as a mere "pet" may be somewhat of a put-on: He knows how to read, can talk and sing,[11] and can follow conversations, but often seems confused about what behaviors are expected from a pet. He often functions as a deus ex machina, figuring out what is going on and what needs to be done and then conveying that information to one or more of the children. Carrot and Jet both realize there's more to Sunspot than the obvious, as evidenced by a conversation in "The Greatest Canyon": Carrot: "You ever get the idea there's something he's not telling us?" Jet: "All the time, Dad. All the time."
• Carrot[12] Propulsion (voiced by Kyle Rideout)[7] is Jet's father. His name from his home planet includes the sound of an elephant trumpeting and a parrot squawking. He tends to be goofy, like Jet. He often stays home while Celery takes the kids on adventures into outer space, as he doesn't really like going in the flying saucer. Carrot often cooks wacky dishes such as deep-fried lollipops.
• Celery[13] Propulsion (voiced by Meg Roe)[7] is Jet's mother. Celery is smart and often takes the kids to space. Her name from her home planet includes the sounds of banging, buzzing, and clanging. She normally drives the family vehicle, as Carrot's driving makes her nervous. She likes racing against her brother, Zucchini.
• Face 9000 (voiced by Brian Drummond)[7] is a computer. He is a cyan face with blue facial features projected from a small, round ball. He has a younger brother, Face 9001. Face 9000 knows everything about science, and often pops up to answer the kids' science questions. In "Face on the Fritz", he gets an upgrade. He has a tendency to get jealous easily.

Collective name for Earth natives used by the Bortronians.

• Sydney[14] Skelley (voiced by Dalila Bela (season 1), Vienna Leacock (in Back to Bortron 7-season 2))[7] is a girl with black hair and green eyes. She idolizes a character named Commander Cressida, named after the moon of Uranus, who has a dog named Sirius, named after the brightest star in Earth's night sky. Sydney is imaginative and very friendly, often acting as the voice of reason for the kids. In "How Come the Moon Changes Shape?" she danced with Jet, in "Kid Kart Derby" she hugged him. Her mother is Dr. Amy Skelley.[15] Sydney's motto is "A kid's place is exploring space." Her friendship with the Propulsion family gives her many opportunities to do just that, which makes her a happy girl. She is named after Sydney, Australia.
• Sean[16] Rafferty[10] (voiced by William Ainscough (seasons 1-Our Sun is a Star!), Grady Ainscough (in You Can Call Me Albedo-Moon Face), Glen Gordon (in Lone Star 2 - Rocket Kids!-Sean Has a Cold), Anthony Bolognese (Space Camp)[7] is a boy with light brown hair, gray eyes, and freckles. Sean probably has asthma; he is shown breathing into a brown paper bag in "Jet Cooks Dinner", and he mentions once when the children are in space that sometimes he has trouble breathing. He is smart and wants to be an astronaut when he grows up, but he has slight claustrophobia. Sean likes to follow the Scientific Method, as shown in many episodes; he even has his own song about it. His mother is Dr. Rafferty. Sean idolizes Neil Armstrong, and has his action figure, which he takes along on their space trips.
• Mindy[17] Melendez[18] (voiced by Jaeda Lily Miller)[7] is a 5-year-old girl (she was previously four, but turned five in episode "Mindy Turns Five") with brown eyes, dark brown hair in two pigtails, and a hat that looks like a teddy-bear face. In season 1, she stayed on Earth when the others went into outer space; she was not allowed to go any further than Jet's backyard. In season 2 she became allowed to travel past Jet's backyard, as she turned five, so she now accompanies the others as they travel into space. She is the only one who knows Mitchell is spying on Jet and is out to expose him.

• Zucchini (voiced by Ian James Corlett) is Jet's maternal uncle and Celery's brother named after the food zucchini. He is a garbage collector on Bortron and works for the East Galaxy Garbage Company, Bortron 7 Division, using the Big Bortronian Junk Sucker (BBJS).[19] He is very kind to the kids, but also dimwitted at times.
• Moonbeam is the pet of Uncle Zucchini. She looks similar to Sunspot, but Moonbeam is blue and plays electric guitar (left-handed).
• Eggplant (voiced by Tabitha St. Germain) is Jet's aunt, Zucchini's wife, and Zerk's mom. She is an intergalactic travel writer just like Carrot and Celery.
• Zerk (voiced by Meg Roe) is Jet's cousin.[20] He calls Jet to ask when the first Earthie visited Bortron. He visits Earth in "Zerk Visits Earth." Zerk is very energetic and hyperactive. In "Whole Lotta Shakin'" and "Asteroid Belt Space Race", he is shown to be very competitive.
• Spinach is Celery's cousin.[21] Celery calls him when the van/flying saucer is not working and she needs advice.

• Mitchell Peterson (voiced by Spencer Drever (season 1), David Raynolds (season 2), Dylan Schombing (One Small Step), Gordon Cormier (Space Camp))) looks similar to Sean except that he wears glasses and a hat. Along with Mindy, he is younger than Jet, Sean, and Sydney. For his age, he appears to be smarter than Mindy, even knowing about and building an exact replica of the Saturn V rocket. Mitchell has a tendency to be sarcastic and sometimes blunt. He is suspicious of the Propulsion' behavior and always wants to expose Jet's alien identity but inevitably fails. Nonetheless, Jet is nice to him. A running gag in the series is whenever he is spying on Jet, Mindy sneaks up on him which he finds annoying. In "Holidays in Boxwood Terrace" it is revealed that he only pretends to be mean and he is really shy and wants to be friends with Jet, Sean, Sydney, and Mindy, but he doesn't know how to do it. In the end, the kids welcome him into their group. His grandfather was a farmer, which he mentions in "Eye in the Sky."
• Mr. Peterson is Mitchell's dad (voiced by Ian James Corlett) and addresses other people by their last names, calling Mitchell "Peterson" and using "Propulsion" to refer to Jet and Carrot. In the episode "Mindy's Weather Report" he calls himself the self-appointed safety officer for the neighborhood. He, like his son, can be a bit full of himself. He is an expert at playing mini-golf.[22] He is also a big soccer fan.[23]
• Dr. Rafferty (voiced by Keegan Connor Tracy) is Sean's scientist mother. She and her co-worker Berg appear in "Visit to Mom's Office." She helps Mindy identify a meteorite in "Mindy's Meteorite Stand." Dr. Rafferty is patient, smart, and loving. In "Visit to Mom's Office", she mentions that she felt like an alien when she was a child.
• Dr. Bergs[24] (voiced by Brian Drummond) is a man who works with Dr. Rafferty. They later appear as judges for the baking competition. Dr. Bergs can be rather silly at times. He loves drinking coffee and always has it in his hand. Sunspot always steals his watch.
• Dr. Melendez[25] (voiced by Meg Roe) is Mindy's mother. She is heard calling to Mindy in "More Than One Moon."
• Riley is a kid in Sean, Sydney, and Mindy's school. He brought in his favorite snow globe for show and tell.[26] He is not shown.
• Lillian (voiced by Amelia Shoichet Stoll) is a friend of Mindy's. The two girls dig a small "Grand Canyon" in a sandbox while the Propulsions and the other children visit Valles Marineris on Mars.[27] Lillian is a girly girl but isn't the sharpest tool in the shed. She can be quite forgetful, seeing as how she told Mindy what her "surprise" present was.
• Lillian's mom (voiced by Ashleigh Ball) is heard in "Mindy Turns 5", when she calls Lillian because she has to go to class.
• Beep[28][29] is a robot who lives at the Deep Space Array (DSA). She has a twin sister, Boop, who is a Rover on Mars.
• Dr. Skelley (voiced by Brenda Crichlow) is Sydney's mom, who also works at the DSA. Like her daughter, she is also a fan of Commander Cressida. She is a robotics engineer.

• The Great Galacto (voiced by Mark Oliver) is Jet's idol. He's a TV and web personality who goes on daring space adventures. He speaks with a Scottish accent. Like Sunspot, he is allergic to comet dust, which causes him to shrink. He went to the far-off planet of Mascarpone to locate the cure, deshrinkulum.
• Stella Singularity (voiced by Viva Lee) was the Great Galacto's number-one fan until Jet took her place. Stella got jealous, and went to planet Earth to confront Jet, but winded up going to space camp, and was placed on Mitchell's team. Stella is sarcastic and narcissistic; she always wants to be the best at everything, does not understand teamwork, and is frequently seen primping herself. When she got stuck in a web in the caverns of Mascarpone, she realized the value of teamwork. From that point on, she apologizes to Jet for how she acted and is nicer to him and the others from that point on.
• Dr. Chandra (voiced by Ana Sani) is an astronomer and "expert on alien life," who visited Boxwood Terrace to judge the spaceship design contest at space camp. Mitchell tried to tell her that Jet is an alien, but to no avail.
• Aurora and Houston (voiced by Diana Tsoy and Gabriel Jacob-Cross respectively) are two kids who invite Mitchell and Stella to join their team. They love space, and emphasize the importance of teamwork.

Emily Ashby of Common Sense Media rated it a 5/5, saying "Thoroughly engaging and packed with educational content, this exceptional series is a fun way for kids to learn about science and astronomy. Jet's excitement for the human experience is matched only by Sean and Sydney's eagerness to learn all about outer space; put the three of them together, and it's a true celebration of the joy of discovery. Whether it's executing a rescue mission for a Mars rover or combining daily chores with experiments in force, Jet and his friends have a lot to teach kids through their own experiences."[48]

Gina Catanzarite of Parent's Choice said "Although the vocabulary and science explanations may be beyond the scope of the youngest viewers, the premise, characters, interesting art direction and upbeat action should hold their attention. Older kids are more likely to grasp the facts and even if they don't remember them all, Ready Jet Go! will at the very least inspire curiosity, and plenty of questions when they take the time to gaze up at the skies above them."[49]

The series has gained 34.3 million viewers, according to PBS, including 10.2 million on broadcast television. It outperformed channel average by 32% in its first three weeks. The series has also been streamed over 146 million times on the PBS Kids website and app since January 2016.[50]

• The series was awarded a Parents' Choice Silver Honor.[49]
  • The series won a Parents' Choice Award again in 2018.
  • The online game Jet's Bot Builder won the 2019 Parent's Choice Silver Award.[51]
• The series was awarded a Common Sense Seal by Common Sense Media.[52]
• Jaeda Lily Miller was nominated for a Young Artist Award for her performance as Mindy[53]
• Cynopsis Kids Imagination Awards:
  • 2017: Nominated for Best Use of Music in a Kids Series, Educational Series/Special – STEM, Mobile App – Preschool, Preschool Series, and won Song for a TV Series/Special/Movie, tied with Splash and Bubbles.[54]
  • 2018: Won Best Use of Music in a Kids' Series, tied with Wonderama, Online Game tied with The Loud House: Lights Out, and was nominated for Preschool Series or Special.[55]
• Back to Bortron 7 was nominated for an Environmental Media Award for Children's Television.[56]
• The Space Scouts app was a 2020 Webby Award honoree.[57]
• At the 2017 KidsScreen Awards, the Space Explorer app was nominated for Best Learning App—Smartphone, and the show's website was nominated for Best Website.[58]