NASA
On Saturday, NASA astronaut Butch Wilmore radioed NASA Mission Control reporting that he was hearing a heavy, pulsing sound coming from the Boeing Starliner spaceship.
"There's a strange noise coming through the speaker," Williams said "I don't know what's making it," he later added.
The conversation was uploaded by a NASA Space Flight forum member on Saturday, which was then spotted by Ars Technica.
Wilmore launched on the Boeing Starliner in June with astronaut Suni Williams. The two were supposed to return to Earth after about a week, but instead have been living on the International Space Station for over two months.
The Starliner spacecraft malfunctioned during flight. Five of its 28 Reaction Control System (RCS) thrusters shut down. It also suffered leaks in the helium supply, which is used to pressurize its propulsion system. But the mysterious noises Wilmore heard had nothing to do with either of those issues.
On Monday, NASA revealed the ominous noise was simply a feedback issue between the speakers on the Boeing Starliner and the ISS where it's docked.
NASA/Robert Markowitz
"The space station audio system is complex, allowing multiple spacecraft and modules to be interconnected, and it is common to experience noise and feedback," NASA said on X.
NASA added that the noise will not affect the crew on board.
The eerie recording came just days after NASA finally announced a date for the Boeing Starliner to return to Earth. After months in space, the Starliner will return to New Mexico on September 7 without its crew.
In a mission update on Thursday, NASA said that the "uncrewed Starliner spacecraft will perform a fully autonomous return with flight controllers at Starliner Mission Control in Houston and at Boeing Mission Control Center in Florida."
This was shortly after the space agency decided that the aircraft was unsuitable for bringing NASA astronauts Suni Williams and Butch Wilmore back to Earth.
They are now scheduled to return via the SpaceX Crew Dragon in February 2025.
NASA Administrator Bill Nelson explained the decision to bring the Starliner back uncrewed during a press conference on Saturday at the Johnson Space Center in Houston, saying that it was because of a "commitment to safety."