A group of scientists, designers and architects is developing over the next 100 years a spacecraft that will allow humans to live permanently in space, even though they'll never live to see it.

"It's a worldship, which means that basically is a fully self-sustaining spacecraft that has a complex ecosystem, that has simulated gravity, a propulsion mechanism to allow it to orient and move through space, and ultimately a habitat for humans so that we can live up there," said CBC science columnist Torah Kachur in an interview with CBC Radio's Homestretch.

She said the ultimate goal is to continue human space exploration and settlement in space.

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CBC science columnist Torah Kachur

"But also if there was to be some sort apocalypse — some sort of nuclear war, some sort of flood, meteorite coming down to rain down on us — this would be our little lifeboat."

The project was started last year by Icarus Interstellar, a non-profit foundation started in Alaska with the goal of sending humans on space journeys between the stars by 2100.

The ship envisioned by the group, which has members around the world but mainly in the U.S. and Europe, is a giant cylinder about 20 kilometres long and five kilometres in diameter that could support 50 to 500 people.

Cylinder full of soil

One of the key components will be a habitat that can sustain life and grow food in space. That component is the responsibility of Project Persephone, led by Rachel Armstrong, a professor at the University of Greenwich in the U.K.

She is developing a synthetic soil that could support plants, microbes, and other things necessary for a self-sustaining ecosystem in space.

"Essentially it's about growing an ecology there that isn't just something that's been ripped up off the Earth, but has been grown specifically for that particular environment," Armstrong told Kachur.

Humans would live in underground burrows in the soil, connected by tunnels and passageways.

Scientists have proposed sending just 50 or 100 people to begin with, to leave room for them to reproduce. Kachur said there has also been talk of sending up a "seed ship" with sperm, eggs and embryos that could be grown in artificial wombs – a technology that isn't close to reality yet.

Other challenges faced by the project include figuring out a way to propel and steer a ship that big through space.

And over its 100-year lifetime, the project could cost billions or trillions of dollars, Kachur said.

In any case, is it crazy to think we can live on a starship in 100 years? Kachur asked Armstrong that question, and she didn't think so.

"The 100-year mark is really an acknowledgement that in the next phase in astronautical exploration," Armstrong said, "That, you know, we'll need to up our game and think even bigger than the way that we're thinking now."