The reason NASA uses dry heat sterilization to sterilize components and sub-systems before the probe is assembled is to reduce the source of biological contamination, avoid trouble, and kill biological contamination in the cradle as much as possible to reduce unnecessary harm.
Dry heat disinfection method is an effective sterilization method. There are usually these practices.
Dry baking: using a dry oven, heating 160-180 ° C for 2 hours, can kill all microorganisms, including bacilli. Cauterization and incineration: Cauterization is a direct flame to kill microorganisms, suitable for microbiology laboratory inoculation needles and other metal equipment that is not afraid of heat sterilization. Infrared: infrared radiation is a 0.77 ~ 1000 micron wavelength electromagnetic waves, has a good thermal effect, especially 1 ~ 10 micron wavelength thermal effect is the strongest, is also considered a dry heat sterilization. Microwave: microwave can make the medium messy polar molecules in the microwave field under the action of the wave frequency back and forth movement, mutual collision and friction and generate heat, the temperature of the medium can be increased, and thus at lower temperatures can play a disinfection effect.
NASA in the detector before assembly, the use of dry heat disinfection method of each component, sub-system disinfection can effectively disinfect each component, reduce the presence of microorganisms, in order to prevent the Earth microbes into space, and other planetary organisms cross-contamination to bring harm.
Every planet's existence is valuable. Microorganisms brought out from Earth may, due to a lack of natural enemies, multiply and cause disruption of the ecological balance, possibly leading to the extinction of a species on the planet. This is all unnecessary.
That's why NASA also uses dry heat sterilization to sanitize components and subsystems before the probe is assembled.