The widely anticipated launch of Boeing’s Starliner spacecraft carrying two National Aeronautics and Space Administration (NASA) astronauts was halted and postponed just before the launch, according to statements.

The hold occurred just as the first minute in the countdown for the Starliner Crew Test Flight carrying NASA astronauts Butch Wilmore and Suni Williams passed, according to updates provided by Boeing Space, NASA and the launch service provider United Launch Alliance (ULA). The spacecraft was preparing to launch from the Space Launch Complex-41 at Cape Canaveral Space Force Station in Florida, according to NASA. Boeing livestreamed the event.

“Teams have scrubbed today’s launch attempt for @BoeingSpace’s #Starliner Crew Flight Test due to an automatic hold of the ground launch sequencer,” a post on X from NASA at 12:22 p.m. EDT read in part.

The halt was “due to the computer ground launch sequencer not loading into the correct operational configuration after proceeding into terminal count,” NASA further explained via a statement. “The ULA team is working to understand the cause.”

The test flight would reattempt to launch at 12:03 p.m. EDT June 2, NASA added. (RELATED: Boeing Space Flight Delayed Over Technology Failure)

The process to enter the Starliner, the ULA Atlas V rocket, and launch pad systems began immediately, ULA announced. Wilmore and Williams then prepared to exit the spacecraft, according to NASA.

The launch would have seen Boeing’s CST-100 Starliner make its maiden manned voyage to and from the International Space Station (ISS). “This critical step for the program is meant to demonstrate Starliner’s launch-to-landing capabilities. The test flight will prove the team’s readiness to achieve NASA certification and fly long-duration missions for the agency,” according to the Boeing Starliner website.