A SpaceX Falcon 9 rocket with a crew of four aboard the Crew Dragon spacecraft scrubbed prior to liftoff for a mission to the International Space Station from pad 39A at the Kennedy Space Center in Cape Canaveral, Fla., Wednesday, March 12, 2025. (AP Photo/Terry Renna)2025-03-12T23:10:16Z CAPE CANAVERAL, Fla. (AP) A launch pad problem prompted SpaceX to delay a flight to the International Space Station on Wednesday to replace NASAs two stuck astronauts.The new crew needs to get to the International Space Station before Butch Wilmore and Suni Williams can head home after nine months in orbit.Concerns over a critical hydraulic system arose less than four hours before the Falcon rockets planned evening liftoff from NASAs Kennedy Space Center. As the countdown clocks ticked down, engineers evaluated the hydraulics used to release one of the two arms clamping the rocket to its support structure. This structure needs to tilt back right before liftoff.Already strapped into their capsule, the four astronauts awaited a final decision, which came down with less than an hour remaining in the countdown. SpaceX canceled for the day. The company did not immediately announce a new launch date, but noted the next try could be as early as Thursday night. Once at the space station, the U.S., Japanese and Russian crew will replace Wilmore and Williams, who have been up there since June. The two test pilots had to move into the space station for an extended stay after Boeings new Starliner capsule encountered major breakdowns in transit. Starliners debut crew flight was supposed to last just a week, but NASA ordered the capsule to return empty and transferred Wilmore and Williams to SpaceX for the return leg. ___The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institutes Science and Educational Media Group and the Robert Wood Johnson Foundation. The AP is solely responsible for all content.an astronaut launch for NASA on Wednesday night.