We need to think about microbes from the very beginning of the design process.   We must design for the presence of microbes and their beneficial and unpleasant habits.   That means that we must know how they behave, not just on Earth in full gravity, but also in space where everything is in microgravity.

We must also be prepared to administer medical treatment when necessary.

We need to know how they multiply and whether the conditions on a Space Station will help this process.
Typically micro-organisms may spread:

  • In the air
  • Through water
  • In food
  • On contact with surfaces
  • As a result of Laboratory accidents
We also need to understand the processes of transmission.

Design the air conditioning system to remove bacteria-sized, and if possible, virus-sized particles.  Filters and ionization of the air can assist in this.  It is important to keep a constant and sustained flow of air so microbes cannot concentrate in stagnant air and can be drawn to filters where they can be removed from circulation.

Controlling and maintaining humidity prevent airborne molds and fungi from being able to find a lace to grow.  Finally, the air quality should be tested on a regular basis, and remedial action undertaken if it is below standard.

Go to Waste system

There are two water systems on the Space Station.  One provides fresh water for drinking and all other purposes, while the other is a sewage and wastewater recycling system.

Go to Waste system

Food is available in pre-prepared, pre-sealed containers.  It can be cooked in these containers and eaten directly from them.  The possibility of food poisoning is therefore reduced to an absolute minimum.  However, some food-stuff will not be supplied in this form, including that grown on the Space Station in the hydroponic facility.  Here, food

Go to Food

Food preparation surfaces are usually the most contaminated and potentially dangerous in the home!  On the Space Station the situation is likely to be similar, so special precautions are are taken to check that surfaces are clear of microbial infection.  A test kit is available whereby cotton swabs containing indicator dyes are wiped across the food preparation surface.  If they indicate the presence of microbes by changing color, the surface can then be swabbed using an antiseptic paper towel.  Both the test swab and towel are consigned to the garbage after use.

Personal items - bedding and clothes - can carry microbes so these are changed and washed regularly.

The bathroom is always a source of potential infection.  It attracts molds which like to grow in damp corners, and whenever the lavatory is flushed an aerosol of germ-carrying water rises from the bowl.  The toilet on the Space Station seals, so the aerosol problem does not occur.  The facilities are personalized and it is each crew member's responsibility to clean these after use.  A small washing machine is provided in the bathroom for this purpose.

Other surfaces that are handled regularly - keyboards, buttons, grab-handles - receive regular cleaning with antiseptic towels, which are also designed to dissolve grease.

A vacuum cleaner is available to remove surface dust and spills.  Dust - which contains microorganisms - often collects through airflow and static charge.  This is removed by vacuuming.

Laboratory Accidents
Laboratory accidents are potentially the most serious biological hazard on the Space Station.  Some experiments involve the use of highly dangerous pathogens.  Handling procedures must be followed at all times to minimize risks.  Should these fail, the equipment and laboratory itself is designed to prevent the escape of microbes into the main areas of the Space Station.

This is achieved by having an airlock entrance to the Biological Research Laboratory, and by maintaining the air in the laboratory at a slightly lower pressure than that in the main areas of the ship.  The result is that air flows into the lab from the station, and not the other way around.  Any microorganisms in the laboratory atmosphere are likely to remain in the laboratory atmosphere and are unlikely to escape into the main station air system.  The air-conditioning system in the laboratory draws the lab air through its own filtration and cleaning system, before the air is recirculated into the laboratory.

Inside the laboratory most experiments and procedures are carried out in a second level of containment, known as a glove box.  This also operates with a low pressure system, to prevent microbes escaping to the laboratory.

Waste water is another route for contamination.  Waste from the laboratory is heat-treated - ie boiled - and exposed to ultra-violet light irradiation which destroys most pathogens.  It is also subjected to chemical decontamination, with disinfectants.  Any water waste associated pathogens that are thought to be able to withstand these treatments is separately bottled, sealed, and stored before being returned to Earth for specialized disposal.

Medical Facilities
Medical facilities will be available on the Space Station.  Some decisions will need to be made at an early stage in the design, about the type and capability of these facilities,.

In the event of a very serious emergency - medical or otherwise - the crew can escape back to Earth within hours using the emergency escape system.   Once back on Earth, injured or ill crew members can receive any necessary treatment.   The level and type of medical facilities on Space Station 2020 are therefore essentially governed by cost considerations - balancing the cost of on-board facilities against the cost of returning a patient to Earth -  rather than medical needs and contingencies.   Additionally, the abilities of the medical crew need to be matched to the medical facility on the Station.   There is no point in having a superbly equipped medical room, that no crew member has the qualifications or experience to use.

The  design of our Space Station can help.   We need to plan the design to take account of the way infectious agents are spread. Micro-organisms have very little control over where they go.  They are reliant on their vector, the medium they live in.  They cannot decide, as a higher animal might, that they will go somewhere and do something.  All they can do is make the most of the medium they are in.  This is often hostile and kills them, so they have developed the strategy of rapid and exponential reproduction, as soon as conditions are right and and the opportunity occurs.   Additionally they can go into sustained stasis, if conditions are unpleasant but not life-threatening.


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