So Part 2 of securing an edible food system would occur after the explorers land, and establish a colony on Titan. If these were the first colonists, they would need to subsist off the supplies and methods of their traveling spacecraft. Explorers could continue to grow foods in this closed system for many months while they build and establish a more permanent base.
What a permanent food system start to look like?
The permanent base would need to provide growing conditions that were habitable of plants and humans. In addition, the faint glow of the sun would require the colony to have an artificial lighting system.
As with the crops on the space travel, the colony would want to create a system by which many different crops could be produced on a continual basis. One difference would be that the colonists may also grow and raise other food sources, such as animals, and even foods for enjoyment and relaxation.
My first blog spent fair amount of time talking about the types of plants that we could grow, and this would be replicated on the Titan colony. With more space, these colonists could grow vast fields of varied crops. They might even be able to grow plantations of corn or wheat to fulfill their desire for breads or sugar. This would be a great dedication to space/resources, but a long-term colony might make this commitment.
In addition, the colonist may travel with eggs in stasis, so that they can raise fish, small birds, even insects for protein. With fish, for example, the explorers could use the popular system of hydroponics to grow crops alongside a fish species, such as Tilapia. The crops benefit from nitrogen in the fish waste, and the fish benefit from the constant improving the water quality. Other, similar systems, could be established with chickens or even fungus-farming ants. Each of these could supplement the protein of the colonists, but the system could be much more sustainable.
For example, a new group has started a project in Chicago called The Plant, which could be a good model of efficiency. This building is modeling a new form of sustainable, vertical farming. The group has begun with a system similar to the hydroponics mentioned above, but they have added other components.
Any biomatter and waste produced in the system is taken to an anaerobic digester, which converts this matter to biogas. The outputs of the digester produce sludge which can still be used as fertilizer for algae and duckweed, which are eaten by the fish. The biogas production runs a turbine which produces electricity to run grow lights for crops as well as other systems in the colony.
In the case of The Plant (plantchicago.com), they also use the electricity to run a commercial kitchen and a brewery. This latter point may seem like a luxury, but after being on a moon, millions of miles from home, a beer may be one thing that helps these monk-like colonists relax. Anyway, the spent grain from the brewery can be used as fish food and fertilizer, so the only thing "wasted" is the colonists.
Lastly, the hydroponics system could be used to clean water for humans to wash clothes and dishes, and even purify water for drinking. In fact NASA researchers and researchers at Purdue University are working "to harness 'waste heat' from industrial sites to warm the soil in cold climates, making it possible to grow crops year-round."
The sustainable possibilities that we are creating on Earth to create better agriculture efficiencies may someday prove to be survival system for colonists on a moon like Titan.