NASA’s Starliner spacecraft has begun emitting unusual noises just days before it is set to undock from the International Space Station (ISS) for an uncrewed return to Earth.
On Saturday, August 31, astronaut Butch Wilmore, currently aboard the ISS, reported the strange sounds to NASA’s Mission Control at Johnson Space Center in Houston. Wilmore noted that a “strange noise” was coming through a speaker inside the Starliner, but he was uncertain about its source. “I don’t know what’s making it,” Wilmore stated during his radio communication.
Wilmore speculated that the noise could be due to an oddity in the connection between the ISS and Starliner. He asked flight controllers in Houston to listen to the audio inside the spacecraft. A few minutes later, Mission Control confirmed they had established a “hardline” connection to monitor the sound. Wilmore, appearing to float inside the Starliner, moved his microphone closer to the speaker, allowing Mission Control to hear the noise. The distinctive sound, described as a pulsing noise similar to a sonar ping, was audible over the communication line. “Alright Butch, that one came through,” Mission Control responded. “It was kind of like a pulsing noise, almost like a sonar ping.”
Wilmore offered to replay the sound for Mission Control, saying, “I’ll do it one more time, and I’ll let y’all scratch your heads and see if you can figure out what’s going on.” After repeating the noise, Wilmore left the matter in Mission Control’s hands, saying, “Alright, over to you. Call us if you figure it out.”
Meteorologist Shares Recording of Unusual Noise
The audio recording of Wilmore’s conversation with Mission Control was shared by Rob Dale, a meteorologist from Michigan, and was first spotted by Ars Technica. The recording captures the eerie sonar-like noises. The cause of the sound remains unknown. Starliner, which has been docked to the ISS for nearly three months, typically maintains communication with the station via a radio frequency system. When docked, however, an umbilical hardline carries audio between the two.
Instances of astronauts noticing strange noises in space are not unprecedented. For example, during China’s first human spaceflight in 2003, astronaut Yang Liwei reported hearing what sounded like an iron bucket being struck by a wooden hammer while in orbit. Scientists later attributed the noise to minor deformations in the spacecraft, caused by pressure differences between its inner and outer walls.
Despite the mystery surrounding the noises, they are likely benign. Wilmore did not appear alarmed by the occurrence. However, these sounds come amid a series of challenges faced by Boeing and NASA with Starliner’s debut crewed flight, which included significant helium leaks and thruster malfunctions. Due to concerns over Starliner’s readiness, NASA announced that the spacecraft would return to Earth without its original crew members, Wilmore and fellow astronaut Suni Williams. Instead, Starliner is scheduled to autonomously return to Earth on Friday, September 6.
Wilmore and Williams will remain on the ISS, planning to return to Earth in February aboard a Crew Dragon spacecraft.