space operations to the solar system must be life-sustaining, or may be
maintained in a state of basic evolution, with strict limits on the
maximum number of spores on the surface of a spacecraft; The efficiency of the program is improved, and these limits are likely to decrease slowly. Of course, other aviation class clean room requirements are basically the same.
Several promising technologies can help contractors reduce the number of spores, reach acceptable levels, quickly determine microbes, and determine the detailed genome of the spacecraft microbes.
II、Aviation clean room / clean room requirements:
8020.12 allows alternative methods to replace 125 ° C dry heat
sterilization as long as the program and quality control are approved by
the NASA Planetary Protection Officer (PPO). These methods are then listed in the approved PP (Planetary Protection) program. By referring to the specification figures, the aircraft hardware drawings can use these unique microbial reduction methods. Microbial
barriers can be used to prevent repeated contamination of previously
sterilized areas; at least 1,244 Pa (5 in. Water) pressure to meet the
need to prevent microbial invasion. High efficiency air filter HEPA (0.3 μm, efficiency 99.97%) is also a recognized highly effective microbial barrier. NASA requires spacecraft assembly to be carried out in a clean room at a minimum level of ISO 8 (Fed. Std. 209E Class 100,000).
III、Aviation clean room / clean room design:
For a Mars
landing mission, the maximum number of spores allowed for the entire
spacecraft is 300,000 (or <300 bacterial spores / m2); all other
targets still have a slope stability requirement. All
surface areas of each spacecraft can have a number of 300,000 spores,
suitable for non-special areas of Mars (most of the surface); including
the hardware within the body (such as cans capsule), the total allowable
amount of 500,000. The pirate number and other
spacecraft that meet the "special area" or looking for life must meet
the requirements of 300,000 and reduce the surface bio-load to 10,000 by
dry heat sterilization, which means that all visible spores on the
surface of the spacecraft will not exceed 30 One.
Most air clean rooms have unknown microbial deposition rates and surface microbial populations, and there are usually no microbiological laboratories that can be put into use immediately. When building a suitable microbiology laboratory to implement NPR 5340.1, the PP program first has to do is make their clean room as sterile as possible. For this purpose, a temporary laboratory can be built using a Class 100 (ISO 5) clean bench and a benchtop incubator. The use of commercially available sinks (capture of microbial radiation dust) and contact plates based on tryptic soy agar (TSA) (for the determination of clean room surfaces) can be performed on aerospace clean rooms (including thermal vacuum chamber, acoustic and vibration facilities ), As well as the initial detection of related equipment. These procedures are primarily designed to detect and calculate the number of heterotrophic, thermophilic, aerobic / anaerobic microorganisms. Most of the microorganisms that survive in space and planetary environments are hi salt creatures, certain varieties of Bacillus and extreme microorganisms.