On Saturday, NASA astronaut Butch Wilmore heard strange noises coming from a speaker in the Starliner spacecraft.
“I have a question about Starliner,” Wilmore radioed to Mission Control, at the Johnson Space Center in Houston. “There's a strange noise coming through the speaker … I don't know what's causing it.”
Wilmore said he wasn't sure if there was some strangeness in the communication between the station and the spacecraft that was causing the noise, or something else. He asked flight controllers in Houston to see if they could listen to the audio inside the spacecraft. A few minutes later, Mission Control radioed back that they were on “hardline” to listen to audio inside Starliner, which has been docked at the International Space Station for almost three months.
Wilmore, apparently floating in Starliner, held his microphone up to the speaker in Starliner. Shortly after, there was an audible ping that was quite distinctive. “Okay Butch, that came through,” Mission Control radioed to Wilmore. “It was kind of a pulsing sound, almost like a sonar ping.”
“I'll do it again, and I'll leave you all scratching your heads and seeing if you can figure out what's going on,” Wilmore replied. The strange, sonar-like audio repeated. “Okay, over to you. Call us when you figure it out.”
A space alienation
A recording of this audio and Wilmore's conversation with Mission Control was captured and shared by Rob Dale, a Michigan meteorologist.
It wasn’t immediately clear what was causing the strange and somewhat eerie sound. As Starliner flies to the space station, it maintains communication with the space station via a radio frequency system. Once docked, however, there is a rigid umbilical cord that carries audio.
Astronauts occasionally notice such oddities in space. For example, during China's first human spaceflight in 2003, astronaut Yang Liwei said he heard what sounded like an iron bucket being hit with a mallet while he was in orbit. Scientists later realized that the sound was caused by tiny deformations in the spacecraft due to a pressure difference between its inner and outer walls.
The sonar-like sounds this weekend likely have a harmless origin, and Wilmore certainly didn’t sound upset. But the strange noises are worth mentioning given the challenges Boeing and NASA faced with the first crewed flight of Starliner, including significant helium leaks during the flight and failed thrusters. NASA announced a week ago that, due to uncertainties about Starliner’s flyability, it would return home without the original crew of Wilmore and Suni Williams.
Starliner is now scheduled to fly back to Earth autonomously on Friday, Sept. 6. Wilmore and Williams will return to Earth next February aboard a Crew Dragon spacecraft that launches later this month with just two astronauts.