Video: Change of command aboard International Space Station

NASA and SpaceX officials are moving forward with preparations to launch the next commercial Crew Dragon mission to the International Space Station next week after a Flight Readiness Review Thursday, pending a final evaluation of a discovery by SpaceX that it has potentially been loading slightly more propellant than expected into its Falcon 9 rockets.

Investigators believe a leak of propellant inside the Crew Dragon spacecraft’s propulsion system led to the capsule’s explosion April 20 during a ground test at Cape Canaveral, and a senior SpaceX official said Monday that delays are making it “increasingly difficult” to fly astronauts on the commercial spaceship before the end of the year.

International Space Station commander Jeff Williams set a new U.S. space endurance record Wednesday, his 521st day in orbit over four missions, eclipsing the 520-day record set earlier this year by astronaut Scott Kelly at the end of his nearly one-year stay aboard the lab complex.