# Growing space on an early planetary colony

So, humans in the distant future have launched a sleeper ship to a new solar system. Having shed its light-sails in orbit, the vessel has crash landed on it’s intended World; a barren mars-like planet. The colonists have been awoken from suspended animation, and now have to oversee the building of an immense habitat that will support them and their descendants. The labour will be performed by robots; they themselves are mostly tucked up on the ship, handling the button-pushing.

Until the habitat and its accompanying farms are ready, these people need food. There are 200 of them, (the minimum number judged necessary to start a breeding population) and we have about 150 square metres of space on this lander with which to grow food, (300 assuming we use vertical farms). These guys are growing food rather than storing it because they also need a means of recycling oxygen and, well “organic waste”.

Is this growing space enough to cultivate food for +200 settlers, and if not, what measures can be made to make this cut it? I’m prepared to allow bioengineered crops if necessary.

• Basic Google research would tell you the average daily caloric intake for your people and the calories that can be obtained from various agriculture. There are answers on this Stack explaining how much farmland is needed to support various numbers of people. In other words, -1 for lack of research.
– JBH
Commented Jan 27, 2023 at 21:01

I think you are off by a few orders of magnitude. 150 or even 300m^2 are nowhere near enough to feed 200 people if you grow conventional plants. This question comes to around 50.000 people per square kilometer (equals 1 million square meters) so around 20 square meters per person under some very very optimistic assumptions.

If you want to keep the 150 or 300 square meter restriction you don't 'grow' food in any conventional sense of the word. You just declare that there is a large reactor that produces some nutritious paste. This could be achieved through some bacteria or algae or it could be purely chemistry.

/now have to oversee the building of an immense habitat that will support them and their descendants/

Slightly less immense prefab greenhouses.

These are plastic sheeted tubes with a spiraling springlike internal skeleton (shaped like the letter D, flat side down). They are scrunched up in the ship. Once the ship is down these are expanded outwards. Each tube is 100 meters long and there are a hundred of them. The footprint of the ship is expanded outwards to immediately provide more growing space.

These plastic tubes are not meant to support the colonists and descendants in perpetuity. They are meant to last a few seasons while Immense gets built. The tubes turn out to be more durable than expected which is very fortunate, because there are some serious problems with Immense.

Hmm, this is a hard one. I'd say that, with regular plants, that 150m^2 may not be enough for 200 settlers. I say that because that's less than a square meter per settler to grow food. Even with bio-engineered plants, it won't cut it. I say that there'd need to be a supply of food already onboard and bio-engineered plants for the growing space to be enough to supply 200 settlers. If there was 300m^2, however, bio-engineered plants would do fine on their own.

There seems to be some threshold for yield per unit volume.

If you want to grow stuff and you have the room, you plant regular-looking plants. There are ideas for farming the Salton Sea with plants that can grow in the rubbish conditions out there. Land is almost free, and if you can keep something alive with the local water, then it's all gain. If you have a large greenhouse and a steady temperature, then rice would be hard to beat.

If you only have limited water, and macro plants won't survive, then you have hydroponics and tiny things like algae, possibly with yeast or E-coli if you want to make something complex. The smaller you go, the smaller the doubling time is.

If you have a core hydroponics system, a second option might be to grow something incredibly hardy but slow-growing in the cheaper space just outside.

Best bet keep most of the crew in suspended animation for another year or more and just revive enough to manage the construction of power infrastructure and a large greenhouse / agricultural building. After a year or so they should have an increasing surplus of food and the remainder can be reawakened. It could even happen over several stages if required. When the power and food production is available they can start constructing the habitat proper and reawaken everyone.