So you want to colonizing a planet in another star system

[PopeyesPappy]

using tech that's plausibly within reach someday. No warp drives, no magic. Just a brutally hard, expensive, dangerous project that would take multiple generations and massive commitment.

The first real question is where the hell to even go. The closest candidates we know about with any shot at habitability are Proxima Centauri b at about 4.24 light years (closest, but its red dwarf star is a flare machine that probably strips atmospheres and doses everything with lethal radiation), Teegarden's Star b at around 12.58 ly, GJ 1002 b at 15.8 ly (this one currently looks like the strongest contender because its M-dwarf host is unusually stable with low flare activity), and TRAPPIST-1e at 40.66 ly (farther, but in a system with multiple potentially habitable worlds).

Before committing to send people, we need solid intel on atmosphere composition, surface temperatures, climate stability, radiation and flare history, and long-term habitability prospects. That means next-generation telescopes for spectral analysis and biosignature hunting, plus laser-sail flyby probes for close-up imaging, limb spectroscopy, and dust/particle environment data. Both paths are going to cost a fortune. Telescopes will take decades to develop and deploy. Probes are in early R&D stages (Breakthrough Starshot-style concepts), but not pure fantasy. Experts think laser acceleration could hit 0.1 to 0.2c for tiny probes.

At those speeds, you'd get data back from Proxima in roughly 20 to 40 years flight time plus the 4+ year lightspeed lag, or 200 to 400+ years for TRAPPIST-1. To maximize useful data and reliable transmission home, you'd probably go slower with bigger probes, pushing times toward the longer end. That still gives decades or centuries to mature the manned tech while the probes scout.



Generational ships are a non-starter. Keeping a society stable and sane for centuries in a confined habitat is risky enough on its own. The real killer is the insane life-support mass. Food production, water recycling, air systems. These would eat payload better spent on arrival and survival gear. So the only realistic path is some kind of suspended animation or cryo-sleep for the crew. Research is underway (induced torpor in animals, medical stasis concepts), but human-scale, decades-to-centuries hibernation is currently the biggest single tech hurdle.

Propulsion for a manned mission is next. Near-term (say within 100 years), fusion drives look most feasible, possibly with an initial laser-sail boost from Earth-orbit or ground-based arrays like the probe concept. For farther targets with more development time, antimatter-catalyzed fusion or hybrid antimatter concepts could come online. Catalytic versions might slash fuel mass by 30 to 50%, hybrids by 50 to 70%.

If we crack reliable versions, manned speeds could reach that same 0.1 to 0.2c ballpark. But unlike probes (quick accel then coast), a ship needs prolonged acceleration and especially deceleration to enter orbit or land. That stretches trip times to decades minimum for Proxima, and centuries for anything farther out.



Beyond propulsion, you've got radiation and particle shielding (probably magnetic fields plus mass or active systems), ultra-reliable autonomous operations for decades or centuries with no Earth support including navigation, course corrections, maintenance, cryo stability, medical diagnostics, and long-term monitoring. All this has to function flawlessly without resupply.

Then on arrival you have to wake the crew, get from orbit to surface, and bootstrap infrastructure using in-situ resources plus whatever you hauled. Robots might prep landing zones and habitats ahead, but it's still a hell of a bootstrap problem.

The scale is planetary. Just producing 100 kg of antimatter (even assuming we improve production efficiency from today's near-zero to 2%) would require dedicating 1 to 2% of current global power output for about 100 years straight to antimatter production.

Can it be done? Maybe someday. But it would demand multiple generations funneling huge chunks of Earth's energy, industry, talent, and wealth into it. You guys aren't going to like  the tax implications.

[Nobody]

In other words, we're never gonna colonize another star system. At least, not for many thousands of years.
Hell, we're not even gonna colonize Mars.

If we get to a high velocity, a relativistic velocity, we'll be in great danger from many of the results of high velocity.
Such as the fact that the interstellar medium will act like a brick wall, and any radiation will be blue-shifted to gamma radiation. Among other things.

[PopeyesPappy]

In other words, we're never gonna colonize another star system. At least, not for many thousands of years.
Hell, we're not even gonna colonize Mars.

If we get to a high velocity, a relativistic velocity, we'll be in great danger from many of the results of high velocity.
Such as the fact that the interstellar medium will act like a brick wall, and any radiation will be blue-shifted to gamma radiation. Among other things.

You might like the concept brief I put together on the subject.

https://github.com/russnida-repo/Interstellar-Exploration-Settlement-Concept-Brief/blob/main/docs/mission-brief.md

[Gawdzilla Sama]

"I told Orville. I told Wilbur. And now I'm tellin' YOU. That thing will never fly!"

[Nobody]

It didn't fly, Orville flew! 🤣

[Gawdzilla Sama]

It didn't fly, Orville flew! 🤣

Wrong. Orville just hung on. It's a little known fact that he clinched so tight he sucked up the pilot's seat.

[Nobody]

Yeah, I just bet he did! 🤣