A ground system problem led SpaceX to delay a flight to the International Space Station on Wednesday, a mission originally intended to replace NASA astronauts Sunita Williams and Butch Wilmore, who are stranded.
The new crew must arrive at the Space Station before the two stranded astronauts can return, having spent nine months in orbit so far.
Concerns over a critical hydraulic system arose just a few hours before the scheduled launch. As the clock ticked down on the Falcon rocket's planned liftoff from Kennedy Space Center, engineers were checking the hydraulics used to release one of the two arms holding the rocket to its support structure, reports DW.
Already strapped in, the four astronauts — mission specialist Kirill Peskov of Russia's Roscosmos, pilot Nichole Ayers and commander Anne McClain from the United States, and mission specialist Takuya Onishi of Japan's JAXA — awaited a final decision, which came with less than an hour before lift off.
SpaceX has not yet announced a fresh launch date, but noted the next attempt could be as soon as Thursday.
A scheduled eight-day stay on the orbiting station has dragged on for Wilmore and Williams as Starliner returned to Earth without them last year.
SpaceX's rocket was set to lift off from the Kennedy Space Center in Cape Canaveral at 7:48 p.m. ET (2348 GMT) with the four astronauts set to replace the two others.
NASA has allayed fears over the safety of Wilmore and Williams and the two astronauts have been working on research and maintenance with the space station's other astronauts. Williams told reporters in a March 4 call that she is looking forward to seeing her family and pet dogs when she gets home.
"It's been a roller coaster for them, probably a little bit more so than for us," Williams said. "We're here, we have a mission, we're just doing what we do every day, and every day is interesting because we're up in space and it's a lot of fun."
Bd-pratidin English/ Afia
