Earth’s microbes are a hardy bunch. They can survive in extreme environments, such as inside hot springs at the bottom of the ocean. Some have even remained alive despite being exposed to the ultraviolet and ionizing radiation, extreme low temperatures, and vacuum of space.
The standards for missions vary depending on what the goal of a particular spacecraft. Perhaps a spacecraft is put on a trajectory that won’t put it near the planet or moon’s environment. Other standards address how it is assembled in a cleanroom on Earth, and how it is sterilized.
Despite the best efforts of spacecraft cleaners, some microbes seem to survive conventional cleaning processes. This is why a new method is emerging that uses ionized gas to kill the microbes.
For the full story, see Astrobiology Magazine.
