Nikolai "Kolya" Gerasimov (Alexei Fomkin)
- Adaptation Rename: Surname changed from Naumov to Gerasimov to not confuse with Ilya Naumov (Fima).
Fima Korolev (Ilya Naumov)
- The Lancer: To Kolya.
- Temporal Paradox: Fima is worried about such occurrences.
Yulia Gribkova (Marianna Ionesyan)
- Leaning on the Fourth Wall: Explains that in the future, when scientists invent technology to travel in space and time, they will name the technology as it was named in Science Fiction works.
- Moe Couplet: With Alisa.
- Tomboy and Girly Girl: With Alisa, and the girlier of the pair.
Marta Erastovna the physical education teacher (Natalia Varley)
- Badass Teacher: Throws Jolly U out a second-story window.
Yulia's grandmother (Ludmila Arinina)
- Agent Scully: Does not believe in space pirates and time travel, but does accept that Alisa is in danger.
Doctor Alik Borisovich (Georgi Burkov)
Alla Sergeevna the English teacher (Yekaterina Vasilieva)
Shurochka the nurse (Maria Sternikova)
The other schoolchildren
- Huge Schoolgirl: Albina Fetisova is distinctly taller than the other girls.
- Lovable Alpha Bitch: Albina Fetisova.
- Mouthy Kid: Kolya Sadovsky butts into Alisa and Yulia's conversation with Kolya Gerasimov, and boasts that if he met space pirates, he'd shoot them with a laser.
- One Steve Limit: Averted. Three Kolyas: Kolya Sulima, Kolya Sadovsky, and Kolya Gerasimov.
- Six Student Clique
- The Head: Kolya Gerasimov.
- The Muscle: Kolya Sadovsky.
- The Quirk: Fima Korolev.
- The Pretty One: Albina Fetisova or Lena Dombazova.
- The Smart One: Yulia Gribkova.
- The Wild One: Alisa Selezneva.
Alisa Seleznyova (Natalia Guseva)
- Always Someone Better: Better in class than any of the other students.
- Fake Shemp: When she speaks English, the camera quickly cuts away from her face to the rest of her class. Her voice was dubbed over by the daughter of an English diplomat at the British Embassy in Moscow.
- Friend to All Living Things: Is first seen petting a crocodile at the Kosmozoo.
- Girls Need Role Models: Natalia Guseva ended up being inspired by her role to become a scientist.
- Jail Bait Wait: Some fans were attracted a little too much to Alisa and to Natalia Guseva.
- Kid from the Future: Discussed Trope. She tells Yulia "Maybe I'm your granddaughter," but is probably joking.
- Moe Couplet: With Yulia.
- New Transfer Student: The explanation for her appearance at school.
- Omniglot: "I'm not an expert. I only know eight languages."
- Russian plus English, French, Spanish, Czech, Finnish, Hindi, Chinese, and Japanese.
- Spell My Name with an "S": Alice or Alisa?
- Tomboy and Girly Girl. With Yulia, and the Tomboy of the pair.
The Pirates, Jolly U (Vyacheslav Nevinny) and Rat (Mikhail Kononov)
- Bizarre Alien Biology: Shapeshifters from Saturn.
- Fat and Skinny: Jolly U and Rat, respectively
- Fat Bastard: Jolly U. Vyacheslav Neviny would eventually die from diabetes.
- Hugh Mann: Their movements are stiff and their voices may randomly become deep or scratchy.
- Mean Character, Nice Actor: Vyacheslav Nevinny and the child actors got along very well.
Werther the robot (Yevgeny Gerasimov)
- Berserk Button: Being called a tin can. "I am a biorobot, and nobody has ever insulted me like that!"
- Composite Character: Fulfills the role of several aliens from the book.
[throws head back] "Ha! Ha! Ha!"
Polina (Yelena Metyolkina)
- Bookends: She appears at the beginning and end of the Mini Series.
- Force Field: Protects her from the pirates' weapons.
- Space Clothes: At the end, she wears a silver jumpsuit.
Professor Seleznyov (Yuri Grigoryev)
Grandfather Pavel (Vladimir Nosik)
The Time Institute scientists, Ivan Sergeevich (Boris Shcherbakov), Gogi (Ruben Simonov), Maria (Yelena Tsyplakova)
- Fur Bikini: On the woman in Stone Age costume.
- Wig, Dress, Accent: One in a toga went to Alexandria, one dressed as a marquis, and one dressed in furs with a club.
The future schoolchildren
- Values Dissonance: By our standards, schoolchildren making and launching their own satellite would be ludicrous. By 2084 standards, it is normal.