I've been reading quite a bit about the new efforts by NASA and various private companies and other nations to get back to the moon and possibly even to Mars. The projected timeline for both endeavors is within my potential lifetime.
I remember lying in the floor watching the early forays into space on our black and white television, listening to Walter Cronkite describe what we were seeing. In my head, I can still hear his voice. When Neil Armstrong set foot on the moon it was as though we, mankind, had achieved a victory. It was more than just a U.S. win over the Soviet Union in the race to the moon, it was something that "felt" as though it went beyond that to encompass all of humanity.
One of the things that intrigues me as I read about the possibility of going to Mars is the question of how will they transport enough food for the duration of the trip? If you figure roughly 6 months each way and maybe 90 days on Mars for 4 or 5 people, it will take a good deal of food. The weight and volume of that food will be an issue in the design of the craft and it will affect other things such as the amount of fuel necessary for the trip and space available for other items.
In recent news there has been much ado about various alternative technologies for producing meat-like products. One is through the use of bacteria to grow the tissue. Perhaps that is one of the solutions being proposed for the trip. If a substantial portion of the nutritional needs of the astronauts can be produced on the way, it might alleviate some of the space requirements. I don't know enough about the technology to evaluate the feasibility but, I would guess that waste could possibly be recycled and utilized by the bacteria as part of the matter necessary to produce the food. After all, something isn't created from nothing -- there has to be food to feed the bacteria. It becomes an issue of efficiency in conversion.
Efficiency is one of the biggest constraints in food production. There are widely varying differences in the efficiency of different processes. It is a question of how much input is converted into usable output. With catfish, the conversion is about 1.1 lbs. of feed for 1 lb. of meat. In cattle it is closer to 6 lbs. of feed (on a dry matter basis) to make 1 lb. of meat. I don't know what the conversion rate is with bacteria, but I can't imagine it being possible to do better than 1 to 1.
Even for vegetable production it is something that must be considered. If we take and take from the soil without replenishing that soil, eventually it becomes unproductive. Growing food of any kind is a matter of chemistry. It requires energy and various elements which are extracted and recombined into forms that are usable by us, or by other animals as fuel for growth, maintenance and reproduction. One of the more valuable contributions of plants is that they take carbon out of the air as well as from the soil. That could be useful on a craft in space and would reduce the power requirements necessary for carbon scrubbers to keep the air breathable. The water component is recyclable for the most part and fuel for food production could come primarily from sunlight.
Any way you slice it, food will be one of the major considerations as we venture into space. The astronauts, trapped within their craft, are a microcosm of the same issue we face on our planet. We are all, in essence, passengers on this giant blue marble hurtling through space. We have to manage our resources in new and creative ways as our population grows in order to have enough to last the journey.
No comments:
Post a Comment