Could we build a starship using current technology?

[jeff_wilson]

Originally Posted by Humabout

For what it's worth, accelerating that much for that long would run headlong into relativistic effects that would sap all efficiency. After three or four months, you'll probably be going plenty fast enough to achieve your goal, and without using up nearly so much fuel.
[...]

This is not correct; the mass of the ship remains constant wrt itself, regardless.

[Vaevictis Asmadi]

I recently finished watching all the videos from the proceedings of the Starship Century Symposium. While I don't understand the math, I gathered that with current technology we could use Orions to get between planets in our own solar system quickly, but that travel to another star system would require more advances beyond what we can build now, even for an Orion design.

All the other starship drives suggested in that symposium require either fusion or antimatter fuel, ramjets, beamed power with sails, or something entirely hypothetical like a neutrino drive.

I tried to guess what the TLs would be for each technology they suggested, but didn't have enough context. I have Space but not UT. Actually I really want to know what the TL for each is.


I did get the impression that even electronics won't survive an interstellar journey without a magnetic radiation shield in front of it, and that any reasonable design also needs a magnetic sail for deceleration. At that point, you might as well learn how to turn your mag-shields/mag-sails into beam-sails and/or ramjets.

Then, instead of blowing up nuclear bombs on/near Earth, you "only" have to worry about easily-weaponized giant space lasers (which may actually double as a safer way to launch mass off of Earth in the first place).

[Anders]

Do you want to build a spaceship?
Come on lets go explore
I never see you anymore
Come out the door
It's like you've gone away-
There are so many planets
And stars up there
I wish we could go see them.
Do you wanna build a spaceship?
It doesn't have to be a spaceship.

[Flyndaran]

Originally Posted by Vaevictis Asmadi

I...

All the other starship drives suggested in that symposium require either fusion or antimatter fuel, ramjets, beamed power with sails, or something entirely hypothetical like a neutrino drive.

I tried to guess what the TLs would be for each technology they suggested, but didn't have enough context. I have Space but not UT. Actually I really want to know what the TL for each is.


I did get the impression that even electronics won't survive an interstellar journey without a magnetic radiation shield in front of it, and that any reasonable design also needs a magnetic sail for deceleration. At that point, you might as well learn how to turn your mag-shields/mag-sails into beam-sails and/or ramjets.
...

I think the minimum TL required would be TL9 with a massive multi stage fusion drive and mag sail for deceleration. It avoids the WMD and unreliability of politics, keeping everything with the ship.
Plasma shielding against charged radiation is on the drawing board now, so should be old hat by mid TL9.

There's always the possibility of being advanced in rocketry if you want to keep the classic TL 8 feel.

[Vaevictis Asmadi]

But what kind of fusion drive? In the notes I took while watching, I wrote that fusion-thermal only gets you interplanetary travel; that you need fusion-pulse for interstellar ships. Is that still a WMD?

But the OP did specify infinite political will, so I guess we can assume "The Earth is doomed, get as many rich people to safety as fast as possible and damn the consequences." In which case nuclear bombs in Earth atmosphere aren't off the table either, at least if Mars or the outer solar system count as safety.

[Anthony]

Originally Posted by Flyndaran

I think the minimum TL required would be TL9 with a massive multi stage fusion drive and mag sail for deceleration. It avoids the WMD and unreliability of politics, keeping everything with the ship.

There are ways to make the WMD-ness of a laser lightsail or particle beam sail not too critical -- you just have to put the laser array somewhere where it can't actually hit anything important. I suggest the far side of the moon. It's really the only option that can give you more than 1-2% of c at a faintly modest tech level.

[Vaevictis Asmadi]

Originally Posted by Anthony

There are ways to make the WMD-ness of a laser lightsail or particle beam sail not too critical -- you just have to put the laser array somewhere where it can't actually hit anything important. I suggest the far side of the moon. It's really the only option that can give you more than 1-2% of c at a faintly modest tech level.

Can that be done at TL9?

[Anthony]

Originally Posted by Vaevictis Asmadi

Can that be done at TL9?

Under GURPS? Not entirely clear, but it's plausible. The basic requirement is a good quality lightsail (not a problem at TL 9) and the ability to build ridiculously enormous lasers with extreme beam quality. GURPS TL 9 has sufficiently powerful lasers, but beam quality is unknown.