Providing food question/help (5e) (Sci-fi)

[1Forge]

So in my home brewed sci fi setting for 5e D&D Earth's surface was destroyed. Most of the population died but military personnel and other space goers survived the cataclysm of the interstellar war. They joined corporate colonies that were established on mars. I've been trying to get all the details down for my session next week but I have a problem. I don't know how everyone is being fed. With earth irradiated and constantly plagued with cataclysmic storms crops cannot be grown in the traditional sense, and yet I've already established in previous sessions that mars is overpopulated, without establishing a food source.

I need help brainstorming a food source that the scientists could have produced quickly to feed survivors from earth, and something that could be mass produced to feed a planet. I'm assuming that one person needs at least 500lbs of food a year to survive (2,500,000,000,000 lbs a year for the 5 billion people by the time our adventurers arrive)

Note: They do have FTL methods of transportation and communication though it's expensive, medical research is to the point that they can regrow body parts and essential organs for people (if you can afford it), They do have the moon and Venus available if needed and tenuous relations with an arctic alien planet they had war with (both planets were screwed due to that war). Also most traditional plants we enjoy on earth are extinct but some were saved and bio-engineers have created other plants that serve similar functions. Also power shouldn't be a problem.

If I could get some help brainstorming that would be awesome, thanks either way.

[sajro]

Now is the idea that all the food is created on Mars, or that it is created on Earth and then simply transported to Mars, or what exactly is the circumstances, cause that changes ways of massproducing food. :)

BUt my ideas right know are Algae and Insects.

[Calen]

Hydroponics on spacestations could help, but it seems like the bulk of food would be something grown on mars. Genetically adapted plants to grow on the martian surface could be a big provider.

[1Forge]

Now is the idea that all the food is created on Mars, or that it is created on Earth and then simply transported to Mars, or what exactly is the circumstances, cause that changes ways of massproducing food. :)

BUt my ideas right know are Algae and Insects.

Earth is unavailable for production of almost any kind, Mars has to produce food for it's populous, workers&prisoners who work to clean Earth's fallout, and a few thousand people on Venus.