NASA and Boeing were once again forced to cancel the first crewed launch of the company’s Starliner spacecraft.
NASA astronauts Barry “Butch” Wilmore and Sunita Williams are scheduled to board the Starliner from Florida’s Cape Canaveral Space Force Station on Saturday at 12:25 ET. The flight to the International Space Station would be the vehicle’s first crewed flight.
The launch attempt was aborted with only 3 minutes and 50 seconds left in the countdown; It was another setback for Boeing, which was already dealing with years of delays and budget overruns with its Starliner program.
Officials were trying to try again the next day, but on Saturday evening they announced the flight was delayed “to give the team additional time to evaluate the ground support equipment issue,” according to NASA.
NASA is expected to provide additional updates on Sunday, including when the Starliner capsule might next take off. There are additional opportunities on Wednesday and Thursday, according to NASA.
Starliner’s crewed test flight is needed for Boeing to demonstrate that Starliner can safely transport astronauts to and from the space station. A successful mission could pave the way for NASA to authorize Boeing to conduct routine trips to the orbiting outpost, giving the agency a long-awaited second option for SpaceX’s Crew Dragon capsule.
The decision to cancel Saturday’s launch attempt was made after an automatic hold was triggered in a computer known as a ground launch sequencer that controls operations with the rocket in the final minutes of the launch countdown. The computer is placed next to the rocket on the launch pad.
“These types of holdups occur when a command is sent and the computer cannot verify the appropriate response to a command,” said Dillon Rice, systems test engineer and launch chief at United Launch Alliance. ULA, a joint venture between Boeing and Lockheed Martin, produces the Atlas V rocket that the Starliner capsule carries into orbit.
It’s not yet known what caused the holdup, Rice said.
About two hours before liftoff, a separate problem was detected in the ground instruments used to fill the propellant in the upper stage of the Atlas V rocket, but engineers were able to fix the problem. Tory Bruno, president and CEO of United Launch Alliance, said it is unclear at this time whether the two problems are related.
Mark Nappi, vice president and program manager for Boeing’s Commercial Crew Program, said the Starliner spacecraft performed “extremely well” throughout the countdown despite the late-stage cancellation.
“This is the business we’re in,” Nappi said Saturday at a post-scrubbing news briefing. “Everything has to work perfectly.”
In fact, launch bushes are not uncommon in the world of human spaceflight.
Sunita Williams’ mother, Bonnie Pandya, told NBC News in an interview hours before Saturday’s launch was canceled that her daughter was in good spirits. “Very optimistic. “He’s so happy he’s gone,” Pandya said. “He loves it.”
Boeing’s last launch attempt on May 6 was also canceled about two hours before the countdown after a problem was detected in a valve on the spacecraft’s Atlas V rocket. A separate helium leak was later discovered in the Starliner’s propulsion system, further delaying the crucial test flight.
The rocket’s valve was replaced but not repaired before Saturday’s scheduled flight because the helium leak was unlikely to pose a threat to the crew or spacecraft, mission controllers said at a news conference last week.
Both SpaceX and Boeing developed their spacecraft as part of NASA’s Commercial Crew Program. The initiative began more than a decade ago to support private companies in building new spacecraft to carry astronauts into low-Earth orbit following the retirement of the agency’s space shuttles.
But Boeing has lagged significantly behind SpaceX, which has been operating manned flights to the space station for NASA since 2020.
Saturday’s problem isn’t the only problem facing the Starliner. Software problems on its first uncrewed flight in 2019 forced mission controllers to cut that trip short before the vehicle could dock with the space station. The second attempt was subsequently delayed several times due to fuel valve problems. It will not be possible until 2022 for Boeing to conduct a successful uncrewed flight to and from the space station.
Steve Stich, NASA’s Commercial Crew Program manager, said it’s important for the agency to have multiple spacecraft that can carry astronauts to the space station, and Boeing is close to realizing that capability.
“We are really close to flying this mission and then completing our certification, and we are excited to dive into this,” Stich said. “We’ll fly when we’re ready. And it should be soon.”
This article first appeared on NBCNews.com.