NASA said on Thursday that it would continue to evaluate Starliner's propulsion system performance along with Boeing before the shuttle returns from the International Space Station (ISS).
NASA and Boeing did not provide a new date on the return, which had been set for June 26 after a pushback from the first potential date of June 14.
Last week, NASA further postponed the Boeing Starliner's return to Earth from the ISS, carrying its first crew of astronauts, to allow more time for review of technical issues that had been encountered.
The U.S. astronauts, Barrt «Butch» Wilmore and Sunita «Suni» Williams, lifted off on June 5 as a final demonstration to obtain routine flight certification from NASA.
NASA wants Starliner to become a second U.S. spacecraft capable of ferrying astronauts with the ISS, alongside SpaceX's Crew Dragon, its primary ride since 2020.