Elon Musk gave a glimpse inside the development of his Starship rocket project in a few tweets posted on Tuesday. The tweets showed the project under construction and included some tongue-in-cheek references from the SpaceX CEO as well.

In his first tweet, Musk posted photos of the Starship being constructed at SpaceX’s facility in Boca Chica, Texas, CNBC reported. The images showed the rocket through the windows of a hangar that was filled with additional components and equipment.

Musk captioned the photo, “Droid Junkyard, Tatooine.” The reference refers to a “Star Wars” mythical planet featured in the films.

Not done yet, Musk posted another tweet that showed a metal dome structure being moved on top of the body of the Starship rocket. He labeled this photo, “Area 51 of Area 51.”

The images show the progress that SpaceX is making with the Starship, which is expected to be launched more than 12 miles above the earth’s surface, CNBC reported.

Elon Musk SpaceX SpaceX CEO Elon Musk speaks at a press conference at SpaceX headquarters where he announced the Japanese billionaire chosen by the company to fly around the moon, on September 17, 2018 in Hawthorne, California. Photo: Mario Tama/Getty Images