For the family of 13-year-old Jhett McAdams, finding a safe way to celebrate Mardi Gras began more than five weeks ago in a small studio Uptown called the NOLArts Learning Center.

The teenager, who has been diagnosed on the autistic spectrum, began learning all about parades through behavior-based therapeutic art, music and drama classes that began in December. The process ended up being a perfect fit, his teachers said, nurturing his curious nature and burgeoning creativity as he learned to find a beat on the drums, paint props and even sew his own costume.

Jhett is part of what art therapist Kate Lacour calls an “ambitious” experiment: finding a way to allow a group of children with varying levels of autism to march in a Mardi Gras parade, as part of a krewe.

Thanks to Lacour and other volunteers, Jhett and six other autistic teenagers and young adults will be throwing doubloons, banging out music on trash-can lids and dancing in this year’s Intergalactic Krewe of Chewbacchus parade, slated to roll at 7 p.m. Saturday.

“Most of them have never even been to a parade, much less been in one,” Lacour explained on a recent Saturday morning as she patiently showed her students how to sew electroluminescent (EL) wire to their costumes to make them light up. “All the stuff we’ve been doing is new to them. But we’re learning to follow routine and practice ideas, so they resonate.”

Lacour and her students were preparing for a dress rehearsal at the Chewbacchus headquarters in Castillo Blanco Art Studios. There, the students would try on their new costumes, drum alongside the Browncoat Brass Band and enjoy a test run in an environment that on parade day will be ripe with the unexpected, including new noises, crowds and strange sights.

Aside from the throngs of revelers expected to attend the parade, Chewbacchus pays homage to “Star Wars,” “Dr. Who,” “Star Trek” and various other science fiction shows and themes. Costumes frequently involve bright lights and loud noises from instruments; without proper preparation, they could prove to be overwhelming to someone on the autism spectrum, organizers said.

As Lacour explained, much of the rehearsal process was focused on how students could experience the parade in a nonthreatening way.

Since December, she has been tracking her techniques through a detailed blog, outlining all the ways she can adjust art or music classes to better prepare autistic students for the inevitable and unforeseen on parade night.

“Mardi Gras can be overwhelming even for folks with the most robust sensory systems, and we are very aware that every step should be taken to minimize irritation from noise, movement, physical sensations and general chaos,” Lacour wrote in the blog. “Because novelty is usually aversive, things go more smoothly when presented in small pieces.”

Some techniques include frequent repetition, such as explaining a sewing step over and over again, or finding ways to break down abstract ideas with concrete examples, like using videos and pictures to help envision costume themes or parade throws.

Perhaps one of the most challenging aspects, she said, was figuring out how to block out unwanted sights and sounds.

To that end, the krewe will be combating outside noise by having the students create their own noise on trash-can lids, thanks to instruction from Clyde Casey, Chewbacchus’ resident sculptural musician and artist.

As Lacour explained, the uncontrollable nature of environmental noise, rather than the volume, seemed to be the biggest irritant to those with sensory issues.

During the parade, volunteers will also have headphones and sunglasses available for anyone who needs them, and each participant will have at least two chaperones.

The Chewbacchus team has been equally supportive, Lacour said, allowing the kids a premium place at the front of the parade lineup, behind the Preservation Hall Jazz Band but before full chaos descends on the area around them.

But a big part of the project, too, is getting those who have misconceptions about autism to open their way of thinking. Although many may not realize it, kids with autism tend to be sensitive, visually creative and able to think “outside the box,” and therefore are “uniquely qualified” to be culture makers, Lacour said.

For instance, it was Jhett who came up with the group’s costume idea. After learning about the concept of “mash-ups,” the teen suggested that all the kids be “Stomp Troopers” — a mix between the high-energy dance and percussion group Stomp and stormtroopers, the soldiers of the “Star Wars” franchise.

To that end, the students have created their costumes by tracing black patterns on Tyvek, a new plastic material, with permanent markers.

The students also worked together to select a logo design and created custom percussion instruments by turning trash cans into drums made to look like stormtrooper helmets.

According to Sarah Ambrose, a music teacher for kids with autism, just the act of preparing for the parade helped to quash notions of what autism is and isn’t.

“A lot of families feel they can’t fully engage in New Orleans culture when they have autistic kids,” Ambrose said. “We want to say nay to that.”

Chewbacchus founder Ryan Ballard said he was equally enthusiastic about dispelling the idea that autistic kids shouldn’t march.

“They came up with the concept, looking for a parade to accommodate children with autism, and I said absolutely,” Ballard said. “The Chewbacchus ethos is one of truly open acceptance.”

Ballard admitted that he worried the kids might have a bad time, but in the same breath he said he was “optimistic” for success because of all the work put in by Lacour, her crew and the helpful members of his Mardi Gras krewe.

“It turns into a swirling, Bacchanalian revelry,” he said, laughing. “It’s kind of our thing to make the impossible look easy.”

As for Jhett, during a recent rehearsal he said he was looking forward to the parade — especially once he learned he could perform for an audience using his homemade instrument.

“I think it’s the music that’s most interesting,” he said.