The article reviews the resistance of bacterial spores, particularly those of *Bacillus subtilis* and its relatives, to various extreme environments on Earth and beyond. Spores are the most resilient form of life known, capable of surviving extreme conditions such as high temperatures, dry heat, UV radiation, desiccation, and chemical agents. The mechanisms that confer this resistance include the presence of spore coats, low water content, high mineral content, and the saturation of spore DNA with α/β-type small, acid-soluble proteins (SASP). These factors collectively protect spores from damage and enhance their survival during dormancy. The article also discusses the role of DNA repair mechanisms, particularly nucleotide excision repair (NER) and recombination-mediated repair, in maintaining spore viability. Additionally, it explores the resistance of spores to ultrahigh hydrostatic pressure and the potential for spores to serve as a means of interplanetary transfer of life. The review highlights the importance of understanding these mechanisms for both scientific and practical reasons, including the potential use of spores in food preservation and the search for life on other planets.The article reviews the resistance of bacterial spores, particularly those of *Bacillus subtilis* and its relatives, to various extreme environments on Earth and beyond. Spores are the most resilient form of life known, capable of surviving extreme conditions such as high temperatures, dry heat, UV radiation, desiccation, and chemical agents. The mechanisms that confer this resistance include the presence of spore coats, low water content, high mineral content, and the saturation of spore DNA with α/β-type small, acid-soluble proteins (SASP). These factors collectively protect spores from damage and enhance their survival during dormancy. The article also discusses the role of DNA repair mechanisms, particularly nucleotide excision repair (NER) and recombination-mediated repair, in maintaining spore viability. Additionally, it explores the resistance of spores to ultrahigh hydrostatic pressure and the potential for spores to serve as a means of interplanetary transfer of life. The review highlights the importance of understanding these mechanisms for both scientific and practical reasons, including the potential use of spores in food preservation and the search for life on other planets.