Two NASA astronauts who traveled at the start of June to the International Space Station were originally scheduled to return home a couple of weeks ago, completing a test flight of Boeing’s Starliner spacecraft.

Instead, the astronauts, Butch Wilmore and Suni Williams, will remain on the station for several weeks longer as NASA and Boeing engineers continue to study misbehaving thrusters on the vehicle.

But don’t call the astronauts stuck or stranded, officials said on Friday. And there’s no talk of a rescue mission.

“We’re not stuck on I.S.S.,” Mark Nappi, the program manager at Boeing for Starliner, said during a news conference on Friday. “The crew is not in any danger.”

Steve Stich, the manager of NASA’s commercial crew program, also tried to allay worries.

“The vehicle at station is in good shape,” he said. “I want to make it very clear that Butch and Suni are not stranded in space. Our plan is to continue to return them on Starliner and return them home at the right time.”

Mr. Stich then added that the right time would be after additional analysis on why five of Starliner’s 28 maneuvering jets behaved oddly as the spacecraft approached the space station. Starliner’s computers, which were autonomously guiding the spacecraft, were able to compensate with the remaining thrusters.