Food in Space
One of the problems for the Space Station is the preservation of food.   Resupply will be infrequent, because the cost of space launches is very high - as much as $1000 per pound weight of payload.   It is likely that the Space Station will be re-supplied only once every six months or so.   This means that six months' supply of food will need to be delivered, almost with every launch, unless food can be produced on board the Space Station from recycled materials.   Additionally, fresh produce will only stay edible for a short time - days at most - so there is no possibility of relying on unprocessed food.

As pointed out, weight is a problem and reducing weight reduces launch costs.   Water is heavy and present in most foods.   It is possible to remove water from foodstuffs, however, by various forms of drying process.   Much of the food used on all types of space mission, for the foreseeable future, is therefore likely to be freeze-dried.

An advantage of this is that the food can be sterilized of bacteria and other organisms during manufacture, so there is virtually no possibility of space-food being responsible for outbreaks of food-poisoning illnesses on the Space Station.

However, living on this highly processed food for months may have psychological and morale effects on the crew.  They will almost certainly start to crave non-processed foodstuffs after a time on the Space Station.  Russian crews aboard Mir developed strange behaviors, as the result of food deprivations.   An orange became a coveted possession and, even the smell, became something from which the crews derived an inordinate amount of pleasure.    See Space Station 2020 Galley.

Two possibilities exist for supplementing the diet, with produce made aboard the Station.   Fresh food - specifically vegetables - may be produced from hydroponic growth, and on board bioreactor production of  food is a possibility.   Quorn, a food product based on micro fungus - Fusarium graminearum - has been on sale on Earth for several years.   It is nutritious and can be made tasty to eat.

Food aboard the Space Station will need to be pre-prepared.   Crews may not be allowed to take fresh produce with them, as this will be likely to turn bad quickly, and could carry undesirable organisms.  However, fresh foods are preferred by many people, as they are tasty and are often more nutritious than preserved foods.  Crews will need to maintain a balanced diet, with mineral and vitamin supplements.  This will satisfy the latter problem, but crews will still have to face months with no prospect of eating fresh foods.  This may have been acceptable to crews of 16th century, sailing ships exploring the globe for the first time, but will it be acceptable to you, as a 21st century astronaut?

Health and Food Safety
 On the Space Station, crews have their health monitored and their diet is personally designed for them.  In space the metabolism changes and it is likely that vitamins and mineral supplements may be necessary.

The main food-related health hazard is food poisoning.  The effects are almost immediate, can be quite painful and sometimes it is fatal.  It is generally the result of poor hygiene.

On the Space Station most food is sterile and pre-prepared in sealed containers.  It is only opened when required, and any food not eaten is recycled through the waste system after the meal.  Used food containers are washed, sterilized and stored as inactive garbage.  Vegetables grown on the Station in the hydroponics facility unlikely to be contaminated, but they are washed before preparation. Food preparation rules are the same as in Earth.

Food-poisoning (on Earth) is becoming increasingly common, largely because people fail to take the necessary hygiene precautions.   The crew of a space station will be as susceptible to food poisoning as anyone else, if hygiene rules are broken.   Freeze-dried food on the Space Station may be highly processed and sterile when it is taken from its packaging, but it will go bad in exactly the same way as it would on Earth.

Eating in microgravity can be messy.  It will be important that crew clean up after them.  Food which is crumbly, such as bread, biscuits and cakes can cause crumbs.  These will float in microgravity, and become not simply a nuisance but a hazard.  They can float off and lodge in undesirable places where they can become a physical blockage and a potential site for microbial or fungal infestation.

While it is not necessary to kill all bacteria in food, methods of food preparation and storage need to good enough to prevent harmful quantities of bacteria or other micro-organisms from accumulating.

Methods of inhibiting Bacterial and fungal growth in food

• Heat-Cooking
• Microwave Cooking
• Boiling
• Irradiation
• Oxygen denial
• Changing the chemical composition

Space food aboard the Shuttle and the International Space Station

Rehydration Station on Space Shuttle.  © NASA, 1997

NASA's present policy and food supply system is centered around Space Shuttle flights, which are of short duration, and don't reflect the conditions that will be encountered on a Space Station.  They do not, for instance carry a refrigerator aboard the Shuttle; there is no real need.   Adequate food supplies can be carried and preserved in other ways that are more efficient and nearly as acceptable to the crew.

Given a chance to fly on the Space Shuttle, wouldn't you be prepared to do without your mother's cooking for a few days?

As space flights become of longer duration and living in space becomes more common, crews aboard space stations and spacecraft will demand a greater variety of more palatable food than is currently available.  Cosmonauts aboard Mir often complained about the diet and sometimes took their own foods aboard, as luxury items - oranges, chocolate, for instance.

All space food currently used by NASA is pre-cooked or preprocessed in some other way.  It is kept in sealed containers or packaging which is only opened when the food is to be consumed.  The food is also cooked in this packaging, in a similar manner to a pre-prepared microwave meal.

Five categories are in use:

• Dehydrated - water removed for storage and added before eating
• Thermostabilized - heat treated to destroy bacteria and enzymes, then sealed
• Natural form foods - ready to eat from the natural state, such as nuts or cookies
• Intermediate moisture - water content  reduced foods that inhibit microbial growth
• Irradiated - foods treated with ionizing radiation that kills all microbes in them

Drinks are contained in bags and are drunk through self-sealing straws that prevent leakage.

Plates and bowls are not provided.  Food is eaten directly from the packaging, which is normally loaded onto a tray for each astronaut.  The packaging is trashed after used, but the tray is re-used.  Standard cutlery - knives and forks - are used, and each astronaut has their own set.  This is reused at each meal, and is cleaned along with the trays using antiseptic-impregnated moist disposable cloths.
 

Teachers Wormhole

© 1999 Satellite Events Enterprises Inc.