Formerly a janitor for Gizmonic Institute ("just another face in a red jumpsuit" according to the theme song), Joel was launched into space by Dr. Clayton Forrester and Dr. Laurence Erhardt as part of an experiment to determine which bad movies were capable of destroying the human mind. Therefore unleashing the worst making the world population bewildered and susceptible to a global takeover. Joel was chosen simply because Forrester and Erhardt despised him for some reason, even though he was by all accounts a competent employee. Although off the record comments from show writers have suggested that it was out of spite of Joel creating better ideas then their own when he worked on Earth. While in space, Joel built the robots Tom Servo, Crow T. Robot, Gypsy and Cambot to keep him company, but used parts that apparently caused him to lose the ability to control when the films would stop and start in doing so. Why exactly he would have control of the movie when the point of the experiment was to destroy his sanity is unknown. In any case, Joel and the bots were alerted to each film's showing by movie sign, forcing them to rush into the theater or risk punishment from the Mads.
Outside the theater, Joel and the bots made weekly "invention exchanges", where Joel and his mad scientist tormentors would come up with wacky inventions in a contest with each other. These sketches were a good match for Hodgson, who began his career as a prop comic; indeed, many of the inventions were items originally found in his standup act.
As their inventor, Joel served as a father figure to Tom, Crow and Gypsy, often scolding them when their antics got out of hand, or when they made crude jokes during the films. In a display of parent-like concern, he opened an umbrella during experiment 403 - City Limits to cover some nudity.
Though bombarded with dozens of horrible films, he tended to take his captivity in benign stride, delivering most of his riffs in dead pan and holding no ill will against his captors and even affectionately calling them "the Mads" (among other amusing nicknames) while riffing on popular culture ("Auntie Em and Toto") or things found in Minnesota ("Milavetz and Associates", a prominent Twin Cities-area law firm).
Joel spent five years aboard the SOL, finally managing to escape after a torturous viewing of Mitchell, which was to be his final experiment. While Joel, Tom and Crow were off in another part of the ship on a camping trip, Gypsy overheard the Mads plotting to fire their new temp worker, Mike Nelson, and thought that they meant to murder Joel instead. To save his life, she found a spare escape pod, the Deus Ex Machina, hidden in the SOL's cargo bay, and used it to launch Joel back to Earth. Furious, Dr. Forrester decided not to fire Mike, and instead "conked him on the noggin" and shot him up to the satellite as Joel's replacement.
Joel crash-landed in the Australian outback, and spent a few years travelling and doing freelance pyrotechnics for the band Man or Astro-man?. Later, he set up a Hot Fish Shop in Osseo, Minnesota. At some point, Joel learned that Dr. Forrester had rigged most of the SOL's components to self-destruct after ten years, and pulled together a spaceship to go back and repair the ship. Joel entered tractor range of the SOL during a showing of Soultaker, and reunited with the bots, meeting Mike for the first time. Though Mike and the bots asked if he could take them back to Earth with him, Joel declined, explaining that the years he spent on the SOL were the best years of his life, and telling Mike "it made a man out of me and maybe, just maybe, it'll make a man out of you too." Once the repairs were finished, Joel boarded his ship and headed back to Earth. Mike was so busy pondering that line of wisdom that he missed his chance at an obvious escape.
- Joel Robinson was played by MST3K creator and writer Joel Hodgson. Joel explained that he used the surname "Robinson" because it "flows off the tongue" better than his given name. It's also a reference to the Robinson family in the 1960s TV show "Lost in Space" (itself an homage to the classic children's novel "Swiss Family Robinson") as well as the novel "Robinson Crusoe".
- Joel appears in every episode from K01 - Invaders from the Deep up to 512 - Mitchell, as well as in 1001 - Soultaker for a total of 108 episodes.
- In the real world, the only known Hot Fish Shop (motto: "Good food isn't cheap, and cheap food isn't good"), which ironically closed the weekend the episode of Joel's return aired, was located in Winona, Minnesota, not Osseo. A new Hot Fish Shop (owned by the same family) opened in Rochester, Minnesota, but sadly closed at the end of the summer season in 2014.
- Joel Hodgson adopted his character's "sleepy-eyed look" and slower drawl to keep continuity from the KTMA days. As Joel would be working in the off hours on show or standup and the next day would be exhausted during taping. He has commented how fans who meet him are puzzled on how alert and average speaking toned he is compared to his character and his disappointment in it.
- At the end of Mitchell, Joel identified the film 7 Faces of Dr. Lao (from which he took the quote for his goodbye plaque) as his favorite movie. This would contradict his earlier statement in Master Ninja II that his favorite movie was Colossus: The Forbin Project.