CAPE CANAVERAL, Florida — Boeing's second attempt at launching a crew aboard its troubled Starliner spaceship was aborted on Saturday with just minutes left on the countdown clock, yet another setback for a program that has faced years of delays.

Two NASA astronauts were strapped in the company's Starliner capsule when the countdown was automatically halted at 3 minutes and 50 seconds by the computer system that controls the final minutes before liftoff. There was no time to work on the latest problem, and the launch was called off.

Technicians raced to the pad to help astronauts Butch Wilmore and Suni Williams out of the capsule atop the fully fueled Atlas V rocket at Cape Canaveral Space Force Station. Within an hour of the launch abort the hatch was reopened.

The team could not get to the computers to troubleshoot the problem until the rocket was drained of all its fuel, said Tory Bruno, chief executive for the rocket maker, United Launch Alliance.

One of the three redundant computers located near the rocket at the pad was sluggish, and all three must work properly to proceed with a launch, he said.

Depending on what needs to be fixed, the next launch attempt could be as early as Wednesday. If it does not blast off this coming week, that would be it until the middle of this month in order to move the rocket off the pad and replace the batteries.

"This is the business that we're in," Boeing's Mark Nappi said. "Everything's got to work perfectly."

It was the second launch attempt. The first try on May 6 was delayed for leak checks and rocket repairs.

SpaceX journey canceled

The Japanese billionaire Yusaku Maezawa said on Saturday that he has canceled his journey around the Moon on a SpaceX rocket, a voyage that had boasted an artistfilled crew, because of development delays.

Maezawa announced in 2018 the "dearMoon" lunar orbital mission, traveling on SpaceX's Starship rocket, which was due to take place by the end of last year.

However, the dearMoon website said in November that the project would be postponed "due to the ongoing development of Starship".

Maezawa said on Saturday that the mission had now been canceled.

SpaceX's two test flights of its mega-rocket last year ended in explosions minutes after liftoff. In a third test in March, its spacecraft was lost as it descended back to Earth.

Agencies via Xinhua