Hello, SFIA audio listeners. In this month's Nebula exclusive, Big Alien Theory,

we're asking the reason alien civilizations might be rare is because most aliens are huge.

To hear it and every episode early and add free, plus hours of bonus content,

check out go.nebola.t.v.t.v.

And use my code, Isaac Arthur.

In order to succeed in space, we must be able to produce as much as possible on-site,

or in-c-to, but what are the most critical resources to harvest, and how do we do it?

Welcome to our June Nebula Exclusive.

Today we're discussing ISRU or in-situ

resource utilization, which includes the collection, processing, storing, and use of materials

found or manufactured on other astronomical bodies, such as the Moon or Mars or Asteroids,

or even the Sun itself.

Today we'll be looking at eight broad categories of ISRU, providing shelter, extraction of

volatiles, regolith processing, energy production, manufacturing and construction, agriculture,

propellant production, and starlifting, and we'll go over them in that order

because I feel it loosely represents your priority list, as for instance, shelter and extraction

of volatiles are what you need to avoid almost immediately dying from a lack of protection

from radiation and vacuum, and to get air and water to breathe and drink. And speaking of drinks, you might want to grab

one and a snack to enjoy for today's episode. You will have brought those on your journey and

presumably have some reserves, but they're your thinnest and shortest margin. You cannot live long

without either. Alternatively, I've put starlifting at the end because while it is your ultimate ISRU option,

short of something probably impossible like raw matter and energy production right out of

...