A fungus pulled from NASA cleanrooms kept surviving tests that were meant to mimic nearly every stage of a trip to Mars. That does not mean Mars is about to be seeded with Earth life. However, the finding underscores a problem space agencies already take seriously. That problem is keeping spacecraft clean enough that they do not carry hardy microbes to other worlds. In the new study, published this week in Applied and Environmental Microbiology, researchers found that conidia, the asexual spores of Aspergillus calidoustus, endured simulated spacecraft decontamination, radiation exposure, Mars-like air pressure, and intense ultraviolet light. Only a prolonged combination of extreme cold and high radiation reliably killed them. “This does not mean contamination of Mars is likely, but it helps us better quantify potential microbial survival risks,” said microbiologist Kasthuri Venkateswaran, Ph.D., the study leader and a former senior scientist in the Biotechnology and Planetary Protection Group at NASA’s Jet Propulsion Laboratory. “Microorganisms can possess extraordinary resilience to environmental stresses.” Configuration of the experimental Mars simulation chamber. Schematic representation of the experimental …