Commercial Cargo Spacecraft

The Commercial Orbital Transportation Services (COTS) program was a NASA initiative launched in 2006 to fund the development of privately owned and operated spacecraft capable of delivering cargo to the International Space Station, replacing the agency's earlier practice of building and operating its own resupply vehicles directly. Under COTS and the cargo resupply contracts that followed it, participating companies retained ownership of their spacecraft designs and launch vehicles, selling transportation services to NASA rather than delivering a government owned system, a commercial model NASA later extended to crewed transportation as well. A commercial cargo spacecraft in this class is distinguished from a national space agency's own government built resupply vehicle by this ownership and contracting structure, even though both classes serve the same basic function of ferrying supplies, equipment and scientific payloads to an orbiting space station.