The bacteria that wont wake up found in spacecraft cleanrooms

by Clarence Oxford
Los Angeles CA (SPX) Dec 04, 2025

Researchers have characterized a bacterium from spacecraft assembly cleanrooms that can enter an extreme dormant state, allowing it to persist where contamination controls are designed to remove nearly all life. The study centers on Tersicoccus phoenicis, a microbe detected in high-grade cleanrooms used by NASA and the European Space Agency to prepare spacecraft hardware.

The team found that Tersicoccus phoenicis can depress its metabolism so strongly that standard methods for detecting living cells register it as inactive even after conditions improve. This behavior raises concerns that some microbes may pass through established sterilization and monitoring regimes because they appear nonviable while effectively remaining intact.

Unlike many bacterial survivors of harsh environments, Tersicoccus phoenicis does not rely on spore formation to withstand cleaning agents, desiccation, and other stressors imposed in cleanrooms. Nils Averesch, an assistant professor in the University of Florida Department of Microbiology and Cell Science and a member of the Astraeus Space Institute, explained that achieving this level of robustness without spores indicates alternative survival strategies that remain poorly understood.

Averesch emphasized that these findings matter for planetary protection policies that seek to prevent Earth organisms from contaminating other worlds or being mistaken for extraterrestrial life. He noted that microbes on the exposed Martian surface remain unlikely to survive, but protected niches such as subsurface fractures, porous soil, or shaded areas beneath rocks could offer refuges where dormant cells might persist.

The work feeds into broader discussions over how to certify spacecraft as sufficiently clean before launch and how to interpret any future detection of biological signatures on other planetary bodies. Coverage in outlets such as National Geographic has highlighted how Tersicoccus phoenicis illustrates microbial adaptation to extreme, human-made environments like spacecraft cleanrooms.

Averesch also leads NASA-funded research at Kennedy Space Center that investigates how microbes can process plastic waste from long-duration missions, turning it into resources for crews. This research forms part of a larger collaboration between the University of Florida and NASA that supports Moon-to-Mars exploration objectives through biological and engineering studies.