CAPE CANAVERAL, Florida —
A problem on the launch pad led SpaceX to delay a flight to the International Space Station on Wednesday to replace NASA’s two stranded astronauts.
The new crew needs to get to the station so Butch Wilmore and Suni Williams can return home after nine months in orbit.
Concerns about a critical hydraulic system arose less than four hours before the Falcon rocket’s planned nighttime liftoff from NASA’s Kennedy Space Center. As the countdown clocks ticked, engineers evaluated the hydraulic system used to release one of the two arms holding the rocket to its support structure. This structure must be tilted back just before takeoff.
Already strapped to their capsule, the four astronauts were waiting for a final decision, which came with less than an hour left in the countdown. SpaceX canceled for the day. The company did not immediately announce a new launch date, but noted that the next attempt could come as early as Thursday night.
Once on the space station, the American, Japanese and Russian crew will replace Wilmore and Williams. The two test pilots had to move to the space station for an extended stay after Boeing’s new Starliner capsule suffered major breakdowns during transport.
The first crewed Starliner 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.
