evidence: Stranded astronaut reports eerie ‘pulsing’ sound coming from troubled Boeing spacecraft — as NASA reveals source of mysterious noise [...] In the recording, Wilmore asked NASA crew in Houston to identify the sound, which was described as both a "pulsing" and a "clanging." [...] As news of the strange sound began to spread across social media, NASA released a statement, acknowledging the latest developments — but insisting that there was nothing to worry about.