First question of many here in my pursuit of grinding out my science fiction story. The problem at hand though involves how a multi-generational ship would survive 500 years hurtling through space, without having to fight the age-old mortal battle of the struggle for resources.

My solution for this is a widely available future appliance that can create anything, from food and drink, clothes, to tools. I'm primarily focusing on the food aspect. Is the idea of 3d printing food out of simple molecules a realistic possibility? Could it be the solution for hunger on an ever growing ship with limited space for resources?

My idea is simply the bonding and reconstruction of molecules and atoms, from the waste produced both in the air and in feces. Take off an electron with 13.6 volts there, and add a proton here, and there's a steak. You see what I'm saying?

  • $\begingroup$ 3D printed food has already been done actually. I don't know there's a commercially available printer for it, or how they actually work, but the technology is developing. $\endgroup$ Jun 24, 2016 at 7:56
  • $\begingroup$ I recall a 3D printer that makes pancakes in whatever shape you want. $\endgroup$
    – JDługosz
    Jun 24, 2016 at 8:32

2 Answers 2


Tea, Earl Grey, hot

It's not only realistic but has inspired the real invention of 3D printers. Star Trek has replicators and it's familiar in the public mind.

A more "hard" SF depiction is central to the Queendom of Sol series by Wil McCarthy. Specifically including its use for interstellar colonization!

What you will need, in terms of resources, is energy to run it. Besides that, it would indeed be the ultimate tech.

McCarthy explores what it means when such a society can't keep up with repair and production of such replication technology. In Pushing Ice, a minor plot branch concerns how leaders can control access to such technology.

  • $\begingroup$ This is exactly the quote I thought of too $\endgroup$
    – Kys
    Jun 24, 2016 at 15:13

While 3D printers can already produce "meat" and various proteins and carbohydrates, the main issue is these are complex and energy intensive devices. Your spaceship could save a lot of on board space and mass by dispensing with hydroponic systems or farms in favour of a 3D printer based system, but then you are pretty much at the mercy of the technical staff and their ability to keep things running over several generations. At least with a farm, we already have 5000 years of practice and most of the systems are self sustaining, largely self correcting and generally robust and not energy intensive.

The downside of a farm based on traditional plant and animal husbandry is the opposite of mechanical synthesis of food: you need lots of room and the ability to provide solar or equivalent energy for the plants at the bottom of the food chain. As well, Earthly food webs and chains generally work in powers of 10, plants absorb and convert 1/10 of the energy of the sun, while herbivores convert 1/10 of the plant's energy, and carnivores convert 1/10 of the energy available in a herbivore. Your tasty tuna sandwich represents 1/100 of the solar energy the plankton converted in the sunny ocean.

Given this, it seems pretty sensible to use genetic engineering to boost the conversion efficiency of plants, and in a limited energy environment like a worldship, go for a vegetarian diet. 3D printers can be used to convert vegetable feedstocks into something more exotic (textured veggie burgers), but I would suggest this is more of a supplement for the passengers and crew than their main source of nutrition.


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