A four-hundred year, one way, trip to Proxima Centauri? Is this sci-fi?

13 August 2025

A proposal to build a multi-generational spaceship — named Chrysalis — that’s nearly sixty-kilometres in length, and would spend four-hundred years travelling to the star presently closest to the Sun, Proxima Centuri, recently won first prize in the Project Hyperion Design Competition.

The vessel, which would be fitted out with tropical forests, schools, workplaces, libraries, and manufacturing facilities, among other things, could house over two-thousand people. Obviously some travellers on Chrysalis, would live their entire lives only on the gigantic ship.

So far, so good. Aside from the ethical matter of consigning your descendants to a life lived on a sixty-kilometre long tin-can, whether they like it or not. But the proposal becomes a little murkier when we learn the vessel’s precise destination:

Chrysalis is designed to house several generations of people until it enters the star system, where it could shuttle them to the surface of the planet Proxima Centuri b — an Earth-size exoplanet that is thought to be potentially habitable.

Proxima Centuri b is thought to be habitable? So to recap: someone wants to spend untold trillions of dollars building a massive spaceship, that will carry some two-thousand people, on a four-hundred year long, one way voyage, to a planet thought to be habitable?

Am I the only one who sees a problem with this?

Wouldn’t we first want to be one-hundred percent certain the planet in question, Proxima Centuri b, was in fact habitable, in Earth-analog fashion, before even drawing up blueprints for the vessel? Apparently not. Chrysalis‘ designers appear to be so confident Proxima Centuri b is fit for human habitation, they’re laying on shuttles to get people on the ground.

Doubtless passengers are relieved they’re not required to parachute to the surface.

Proxima Centuri b was discovered in 2016. The body is a super-Earth, meaning it is larger than our home planet, but still smaller than the likes of Uranus or Neptune. In addition, the planet is located in what is considered to be Proxima Centuri’s habitable zone. Planets within a star’s habitable, or Goldilocks zone, as Earth is in the Sun’s, are generally deemed to be conducive to life. Temperatures are neither too hot, nor too cold, and water can exist in liquid form.

But talk of Goldilocks zones usually applies more to G-type main-sequence stars, or yellow dwarfs, such as the Sun. Proxima Centuri is a red dwarf star, a rather different kettle of fish. I’m not even sure the term habitable zone should be uttered in the same sentence as red dwarfs.

I’ve written about these stars before. They fascinate me. As mentioned, one is the star nearest to us. They also live for trillions of years (compared to billions for many other stars, including the Sun). Red dwarfs will probably be the last stars shining in the universe.

But, as I’ve said previously, they’re not all that life-friendly, particularly for human life. As I’ve written this before, I’ll be succinct. Planets in the supposed habitable zones of red dwarfs, would be — on account of their relative closeness to the star — tidally locked. One side of the planet forever faces the star, and bakes, while the other, cloaked in perpetual darkness, freezes. Most hospitable.

Red dwarfs also emit powerful flares. The outlook would not be good for the inhabitants of a planet in the path of one of these stellar outbursts. Proxima Centuri b may be possessed of some sort of atmosphere, and water might be present, but the planet is no Earth.

What if, on reaching the distant planet, those aboard Chrysalis find it to be completely uninhabitable? Would they be able to return to Earth? No, because the journey is one way. Passengers would be on a multi-century trip to their deaths.

Of course, the Chrysalis project is hypothetical, but that doesn’t mean there isn’t merit in the idea. If the vessel is ever to be constructed, a more suitable destination planet, not just one thought to be habitable, needs to be chosen.