Commercial Space Flight
SpaceX – Space Exploration Technologies – operates the Falcon 9 and Falcon Heavy rockets as well as the Dragon cargo and crewed spacecraft. The company is pursuing reusable launch vehicle technology and future flights to distant targets, including Mars.
Orbital ATK is an American aerospace and defense industry company with a diversified array of products. It operates a number of launch vehicles including the Antares, Pegasus & Minotaur rockets. Orbital ATK is also known as a spacecraft manufacturer and supplier of aerospace system components such as large solid rocket motors.
International Launch Services, based in the United States, offers the Russian Proton rocket on the commercial launch market. The company will also operate launches of the new Angara launch vehicle once it becomes operational.
United Launch Alliance operates the Delta II, Delta IV and Atlas V launch vehicle families to provide launch services to the U.S. government and commercial organizations. ULA is currently developing the new Vulcan launch system to take over from Atlas & Delta.