Elon Musk has been taking inspiration from Game of Thrones. Following the season eight premiere of the dragon-laden fantasy show, the SpaceX founder proposed adding dragon wings to the Starship, the upcoming vessel designed to ferry humans to Mars and beyond.

“With steel membrane wings like a Dragon, we may be able to lower Starship’s orbital reentry temp to ~1000 degrees C, which would allow the whole surface to be uncooled bare metal,” Musk explained over Twitter in response to a tweet from filmmaker Danny Shepherd about the new season of Game of Thrones.

Considering Musk’s meme-laden Twitter persona, it’s unlikely that he’s completely serious. The tech entrepreneur has a habit of adding pop culture references into his work, like by making reference to ‘80s sci-fi comedy Spaceballs by adding a “Ludicrous Mode” to Teslas, or by dropping a rap single titled “RIP Harambe” as a reference to the gorilla shot at Cincinnati Zoo. When asked how serious he was about his dragon wing idea on a scale of one to 10, Musk replied “6.5.”

The Starship is perhaps SpaceX’s most ambitious project. The ship is designed to ferry 100 humans at once to Mars and beyond, with 27 Raptor engines powered by liquid oxygen and methane, unlike the rocket propellant used for Merlin engines and similar rockets. SpaceX aims to set up propellant plants on Mars to harvest these resources, which could create a planet-hopping network enabling explorers to continue traveling out. Its 5,400 tons of liftoff thrust outpaces even the Falcon Heavy, the world’s most powerful operational rocket that flew its first commercial flight last week.

The Starship. SpaceX/Instagram

SpaceX has been exploring new materials for its Starship, moving to a more unique design since the ship’s first unveiling in September 2017. It now sports a stainless steel design that takes inspiration from the Tintin comics, with three giant fins around the base. The steel construction enables transpiration cooling to make the rocket “sweat,” keeping temperatures down during entry. The rocket could enter the atmosphere at temperatures up to 2,700 degrees Fahrenheit, making these cooling ideas critical.

Seemingly random tweets have sometimes resulted in new products before, though. When he declared he was going to make a flamethrower to fund The Boring Company, another Spaceballs reference, it was somewhat surprising to see fans get their hands on the fire-shooting rifles in June 2018. References to PewDiePie’s Meme Review did result in an appearance on the show with Rick and Morty co-creator Justin Roiland. Even Musk’s cryptic tweet about an intergalactic media empire did result in “Thud” around one year later.

As SpaceX’s Dragon capsule gears up to send humans to the International Space Station, perhaps its next project will reference dragons in another way.