NASA engineers are running checks to solve the mystery of why the Falcon 9's engine failed to perform a routine maneuver to lower the rocket's altitude.

The U.S. Federal Aviation Administration on Monday said SpaceX must investigate why the second stage of its workhorse Falcon 9 rocket malfunctioned after a NASA astronaut mission on Saturday, grounding the rocket for the third time in three months.

NASA's SpaceX Crew-9 mission successfully launched from the Cape Canaveral Space Force Station at 1:17 p.m. Saturday.

After multiple delays, NASA’s SpaceX Crew-9 mission finally launched two astronauts into space on Saturday from Cape Canaveral.The mission took off at 1:17 p.m. on a SpaceX Crew Dragon spacecraft, carrying NASA astronauts Nick Hague and Roscosmos cosmonaut Aleksandr Gorbunov to the International Space Station.

From Cape Canaveral in the USA, the SpaceX Crew-9 spaceship with NASA astronaut Nick Hague and Roscosmos cosmonaut Alexander Gorbunov launched on Saturday to the International Space Station (ISS). This ship will return to Earth in February,

From Cape Canaveral in the USA, the SpaceX Crew-9 spacecraft, with NASA astronaut Nick Hague and Roscosmos cosmonaut Alexander Gorbunov, launched on Saturday to the International Space Station (ISS).