The dream to colonize other planets and sections of space is shared by many space agencies and governments from all over the world, but important factors need to be taken into account before such a venture will be possible, and one of them is the risk to contaminate alien worlds.
In the last decades, NASA has employed and followed a series of strict related to the amount of microbiological contamination that is deemed to be reasonable when probes or astronauts are sent to other objects found in the solar system, including the Moon and other objects.
Planetary protection versus progress
Planetary protection rules have been a thorny issue since they were elaborated since any object that is sent into space has some forms of microbes on them. Spacecraft will undergo various cleaning procedures depending on their destination, including exposure to high temperatures with the aim to kill viruses.
As the focus is being shifted from probes and rovers to crewed expeditions, the problem of planetary protection becomes even more complicated. Humans carry a vast collection of bacterias with and within them by nature, and most cannot be removed, which poses major difficulties for some future missions.
After years of pressure from scientists and other members of the space community, NASA has decided to release two temporary directives that will serve as the foundation for upcoming guidelines. The first directive concerns a reclassification of select lunar areas to lower the restrictions for sending humans and probes there.
The second directive is more important as it will change the rules related to Mars, which is currently a Category IV body for landers. Since there is a major interest in finding traces of life and sources of liquid water, extensive rules seek to minimize potential contamination.
While the changes are important, NASA aims to develop and impose them in a careful manner to avoid any consequences in the case of future missions.