This article examines Looping Futures Lost and Found (LFLF), a collaborative sound work developed at Malmö University's Medea Lab remixing audio from NASA's Voyager Golden Record alongside newly recorded expressions of regret gathered during a participatory workshop. Originally created as part of the multimedia installation Tender Time for the 2023 Time Space Existence exhibition in Venice, the work interrogates the Golden Record's idealised representation of humanity by inviting in the absences, vulnerabilities, and hauntings excluded from its planetary archive. Drawing on Derrida's hauntology and Bourriaud's relational aesthetics, we argue that regret functions as a compositional method and a temporal disruption, summoning unrealised futures, unresolved pasts, and the spectral traces of voices omitted from dominant narratives of culture and progress. Through looping, sampling, analogue degradation, live remixing, and collaborative performance, LFLF stages a sonic encounter between archival optimism and contemporary planetary precarity. The article combines theoretical reflection with first-person compositional accounts to examine how participatory sound practices can cultivate forms of collective witnessing, relational listening, and ethical openness toward the ghosts inhabiting cultural memory. In doing so, we position hauntological remixing not simply as an aesthetic strategy, but as a relational practice for reimagining whose voices are carried into the future.