A week ago, NASA officials said they would most likely need to decide by mid-August on how to safely bring home two astronauts who had traveled to the International Space Station on Boeing’s troubled Starliner spacecraft. But on Wednesday, NASA said a decision remained at least a week away.

“We’ve got time available before we bring Starliner home, and we want to use that time wisely,” said Ken Bowersox, the associate administrator for NASA’s space operations mission directorate.

But he acknowledged that NASA could not push back a decision indefinitely. “We’re reaching a point where that last week in August, we really should be making a call, if not sooner,” he said.

The mission, which launched in June with the NASA astronauts Suni Williams and Butch Wilmore, was a test flight that carried people to orbit in the Boeing spacecraft for the first time. It was designed to shake out problems before Starliner was to begin regular missions next year to ferry NASA crews to and from the space station.

The trip was scheduled to last at least eight days, and a longer stay was always considered likely. But the astronauts have now been aboard the space station for more than two months, and uncertainty persists over when they will come home.

The cause of the delay involved problems with Starliner’s propulsion system, which have proved difficult to resolve. Last week, NASA officials said they were considering a backup plan in which Starliner would return to Earth autonomously without anyone aboard.