Enlarge / Boeing's Starliner spacecraft is lifted to be placed atop an Atlas V rocket for its first crewed launch. (credit: United Launch Alliance)

NASA is planning to significantly delay the launch of the Crew 9 mission to the International Space Station due to ongoing concerns about the Starliner spacecraft currently attached to the station.

While the space agency has not said anything publicly, sources say NASA should announce the decision this week. Officials are contemplating moving the Crew-9 mission from its current date of August 18 to September 24, a significant slip.

Nominally, this Crew Dragon mission will carry NASA astronauts Zena Cardman, spacecraft commander; Nick Hague, pilot; and Stephanie Wilson, mission specialist; as well as Roscosmos cosmonaut Alexander Gorbunov, for a six-month journey to the space station. However, NASA has been considering alternatives to the crew lineup—possibly launching with two astronauts instead of four—due to ongoing discussions about the viability of Starliner to safely return astronauts Butch Wilmore and Suni Williams to Earth.