The purchase of five additional crewed flights from SpaceX is part of NASA's effort to maintain continuous operations at the International Space Station.
NASA described the update as a sole source modification to its commercial crew transportation capabilities contract. NASA purchased three flights from the same company in February for Crew-7, Crew-8, and Crew-9. With the addition of five more missions, the total number of flights is now eight.
NASA has only one certified commercial crew transportation provider that is able to provide safe, reliable, and cost-effective human space transportation services. NASA has been working with Boeing on the development of un-crewed flights under the CCtCap contract.
The goal has always been to have multiple providers for crewed transportation to the space station. The only one currently certified to maintain crewed flight to the space station while helping to ensure redundant and backup capabilities through the year 2030.
This purchase of five additional missions is an extension of a partnership between NASA and the company, which began in 2006 when NASA tapped the company to supply crew and cargo to the International Space Station. NASA notes that this latest contract modification "does not preclude NASA from seeking additional contract modifications in the future for additional transportation services as needed."