In 2017, SpaceX formed a subsidiary, The Boring Company,[50] and began work to construct a short test tunnel on and adjacent to the SpaceX headquarters and manufacturing facility, utilizing a small number of SpaceX employees,[51] which was completed in May 2018,[52][53] and opened to the public in December 2018.[54] During 2018, The Boring Company was spun out into a separate corporate entity with 6% of the equity going to SpaceX, less than 10% to early employees, and the remainder of the equity to Elon Musk.[54]