Science in a Food Blog

I wonder, very often, if the only thing (other than gravity of course) that binds us (Indians, in particular) to mother Earth is food ! Just compare an average Indian festival menu to the food that you would get if you were flying in, say, the space shuttle, in a futuristic scenario, to a faraway planet, or even to near-earth orbit as is often done these days. It seems that Steve Lindsey had, for breakfast, during flight day 2 on mission STS-104 in 2001, the following yummy goodies:

• Granola with raisins
• Breakfast Roll
• Pears
• Vanilla Breakfast Drink
• Kona Coffee with cream and 2 sugars
• Earl Grey Tea with sugar

Does not sound too appetizing, but the situation has improved tremendously over the years and the astronaut today has 72 different dishes to choose from (I am sure there was an Indian in the menu design department).

Image Source: NASA

At the International Space Station (ISS), astronauts eat ready-made meals out of cans and pouches and even have a limited supply of fresh fruits and vegetables couriered to them periodically by Russian supply ships. They use an electric oven to warm their food, so that, even if the food tastes like cardboard, it is at least warm cardboard !

Image source: http://static.howstuffworks.com/gif/space-food-3.jpg

Food items to be consumed during space travel/stay are usually dehydrated and packed to make them lightweight, stable over time, and spacesaving. Great care is taken to package the food items. NASA, for example, uses a variety of high barrier polymers as food packaging material. Majority of food packaging materials are made by extrusion of the following five layers: nylon/ethylene vinyl alcohol/tie layer of polyethylene/linear low density polyethylene. A polyamide -based resin - Combitherm® XX film has been more recently used as packaging material for freeze-dried meal components served to astronauts on Space Shuttle missions.

The shelf life of transported food depends not only upon the preservation technique employed, but also on the efficacy of the packaging material, that can prevent the food from coming in contact with extraneous oxygen and water. Apart from possessing good barrier properties, the packaging must also minimize waste that is difficult to handle in space.

And you thought packing lunch for your 8 year old was a pain.


Dining rooms have improved over the years too. To eat in zero gravity, food containers are held in a food tray that can be anchored to a table or wall, or to the astronaut's lap while seated. After the meal, food containers are discarded and the utensils and serving trays are cleaned with "wet wipes."

Based on the average quantities of water, food, and oxygen that people use everyday, water constitutes about 95 percent of the total mass of "consumables" required for human life support within a spacecraft. The wastewater generated amounts to about 30 kilograms per person each day. If water were not recycled by the crew, the mass of water required to be "launched" for a 2-year round trip to Mars with six crew members would be a phenomenal 130,000 kilograms, or 35,000 gallons. Water for long duration space travel is reclaimed from several onboard sources including humidity condensate from the cabin, hygiene water, and urine. It is definitely not as icky as it sounds. The reclaimed water, after physical, chemical and biological purification has been reported to be purer than water we use on earth. Now THAT could be one important incentive for Chennai-ites who face perpetual water scarcity to fly into space. The reclamation setup in the International Space Station involve

• a multifiltration unit, comprising iodinated anion exchange resin, strong and weak cation and anion exchange resins, activated carbon from coconut shell and coal, and polymeric adsorbents to remove specific inorganic and organic impurities.
• a volatile removal unit comprising regenerative heat exchangers, an oxygen sparger, a catalytic reactor, a gas-liquid separator, and a "polishing" ion exchange bed
• a post treatment photocatalytic unit to remove microbicidal contaminants.

Fast food restaurants are still a few decades away in space. Until then, we will have to be content with powdered pudding and cardboard sandwiches.

The Indian Space Research Organization should hire Gayathri for its next mission to Mars.



References
1. http://www.ag.iastate.edu/centers/ftcsc/media/packagingbrochure.pdf