CAPE CANAVERAL, Florida — 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 station so that Butch Wilmore and Suni Williams can head home after nine months in orbit.
Concerns about 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 just 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 come as early as Thursday night.
Once at the space station, the U.S., Japanese and Russian crew will replace Wilmore and Williams. 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.
