SpaceX to bring home astronauts taken to ISS by Boeing

What they're saying: "NASA and Boeing identified helium leaks and experienced issues with the spacecraft reaction control thrusters on June 6 as Starliner approached the space station," NASA said in a statement.

• Since then, engineering teams have conducted more testing, reviewed data and developed contingency plans for a return flight.
• "The uncertainty and lack of expert concurrence does not meet the agency's safety and performance requirements for human spaceflight, thus prompting NASA leadership to move the astronauts to the [SpaceX] Crew-9 mission."

Flashback: Both Boeing and SpaceX were awarded NASA contracts to help develop their human spaceflight systems in order to end the space agency's reliance on Russian systems after the end of the space shuttle program in 2011, Axios has previously reported.

The big picture: NASA has for years said that two different American vehicles capable of crewed flights were necessary, but the two companies have had wildly divergent track records.

• SpaceX, which won a $2.6 billion contract, has completed 42 visits to the ISS in its Dragon capsule.
• Boeing, which won $4.2 billion, has written off $1.6 billion in costs for Starliner, and Wilmore and Williams were on the first crewed test flight.