Sierra Space Corporation, commonly referred to as Sierra Space, is a privately held aerospace and space technologies company headquartered in Louisville, Colorado, with additional facilities in Colorado, Wisconsin, Florida, North Carolina and a testing site at the Marshal Space Flight Center in Alabama. The company makes spaceflight hardware for various applications across the industry. It is currently developing the Dream Chaser spaceplane. The spaceplane was selected by NASA to provide services to the International Space Station under NASA's Commercial Resupply Service 2 contract. The company is also in collaboration with Blue Origin to develop components of the Orbital Reef space station.

Sierra Nevada Corporation is an American aerospace, defense, electronics, engineering and manufacturing corporation that specializes in aircraft modification, integration and other space technologies. The corporation contracts with the United States Armed Forces, NASA, and private spaceflight companies. The corporation is headquartered in Sparks, Nevada, and has 36 locations in the United States, United Kingdom, Germany, and Turkey.