USA – The launch of Boeing’s Starliner, which aimed to lift off on its crewed maiden voyage Saturday, has been scrubbed. The new spacecraft was expected to lift off atop an Atlas V rocket at 12:25 p.m. ET from Cape Canaveral Space Force Station in Florida, carrying veteran NASA astronauts Butch Wilmore and Suni Williams.

But an automatic hold triggered by the ground launch sequencer, or the computer that launches the rocket, stopped the countdown clock at 3 minutes and 50 seconds ahead of launch. Teams safely extracted the astronauts from the capsule so they can return to crew quarters to await their next launch opportunity.

Tory Bruno, president and CEO of United Launch Alliance, which built the Atlas V rocket Starliner sits atop, said to assess the issue that caused the launch scrub, teams will have to get hands-on this evening with the ground launch sequencer. Once the rocket has been drained of fuel, teams will be able to assess the triple-redundant computer system at the launchpad.

“Imagine a large rack that is a big computer where the functions of the computer as a controller are broken up separately into individual cards or printed wire circuit boards with their logic devices. So they’re all stand-alone, but together it’s an integrated controller,” Bruno said. “And we do that to make it easier to troubleshoot them, to swap out parts so that you can replace just one element of it without having to replace the whole thing.” “The third one was slow to come up and that tripped a red line — that created an automatic hold because, although the health system did not note that it came up anomalously, it took longer, and so something is not correct,” Bruno said.

 Mission teams estimate a 24-hour turnaround time. If the issue can be fixed tonight, Starliner could launch Sunday at 12:03 p.m. ET. If not, the next launch windows are June 5 and June 6. “We’ll know more, much, much later this evening,” Bruno said.

Around 10 a.m. ET, mission teams reported a loss of data from ground valves responsible for replenishing the liquid oxygen and hydrogen to the second, or upper stage, of the Atlas V rocket. Both liquid oxygen and hydrogen, used to fuel the rocket, boil off as the rocket sits on the pad ahead of launch, so replenishment is ongoing until liftoff. After evaluating the issue, which prevented the hatch from closing after the astronauts entered the crew capsule for about 45 minutes, mission teams switched to a redundant system for the valve data. Then, teams resumed replenishing liquid hydrogen and oxygen. Fortunately, mission teams were ahead of the expected timeline when the issue occurred, and the countdown to launch resumed, according to the live NASA broadcast.

The valve issue did not cause any safety concerns for the crew, and the hatch on Starliner closed around 11:20 a.m. ET. The mission, called Crew Flight Test, is the culmination of Boeing’s efforts to develop a spacecraft to rival SpaceX’s Crew Dragon capsule and expand US options for ferrying astronauts to the space station under NASA’s Commercial Crew Program. The federal agency’s initiative aims to foster collaboration with private industry partners. (CNN)…[+]