Will the Space Colony children be the Startravelers?

[Anthony]

Originally Posted by Johnny1A.2

But the necessary improvements in so many fields to make even simple sounding rockets would have looked seriously daunting at the time, much less Saturn 5s, which would have looked like utterly unrealistic daydreaming.

That's just an indication of more than one TL. Reaching orbit requires about 4x the performance of rockets they had at the time. Going to another star in a reasonable time period requires more like 100x the performance of THS spaceships.

The other thing, though, is that the technology required for interstellar flight has consequences; doing so in a conventional manner is comparable to the requirements for a type II civilization.

[Flyndaran]

THS certainly has tech that could handle a century or two of functionality sans maintenance. But could anything last thousands upon thousands of years in harsh space outside the solar system without maintenance?
That seems like a different level of tech that even they couldn't really be certain of.

[Anthony]

Originally Posted by Flyndaran

THS certainly has tech that could handle a century or two of functionality sans maintenance. But could anything last thousands upon thousands of years in harsh space outside the solar system without maintenance?

Sure. The problem is there's an inverse relationship between performance and reliability, and there's a minimum level of performance for interstellar travel.

[vicky_molokh]

Originally Posted by Johnny1A.2

Yeah, but we're not just talking about the technical definitions. The word 'superscience' also gets used in a more general way to describe things are that are theoretically possible but thought to be impossible in practice, whether that's technically right or not.

Yeah, rocketry is completely within the physics of 1869. But the necessary improvements in so many fields to make even simple sounding rockets would have looked seriously daunting at the time, much less Saturn 5s, which would have looked like utterly unrealistic daydreaming.

Relativistic starships able to get across the Universe in one lifetime, ship time, are possible in theory, too, but would routinely be described as fantasy or superscience.

Used in what contexts? Because in GURPSy discussions of hard-sciness, it's a term of art which means a very specific thing, much like 'hit points' and 'gravitational constant', and using it in any other sense is likely to reduce clarity of discussion.

[Fred Brackin]

Originally Posted by Anthony

That's just an indication of more than one TL. Reaching orbit requires about 4x the performance of rockets they had at the time. .

Getting into orbit requires 4x the performance of rockets available in 1945. I've never tried to figure the Delta-V of a Hale rocket (1869) but I doubt it's anything like the 1.5 miles per second of a V-2.

Solid v. liquid fuel rockets also illustrates a difference between "theoretically possible" and "unimaginable". Arthur C. Clarke was part of a UK space exploration society while he was a young man just before WWII.

This group did an elaborate conceptual mock-up of what they thought the first rocket to the Moon might look like. They even had it using stages. It's just that they used banks of solid fuel rockets because they were sure that no possible fuel pump could feed a liquid fuel engine fast enough.

This belief is understandable in context. The fuel pumps for one of the Shuttle's main engines weighed 750 lbs and generated 75,000 horsepower. Even technically well aware persons of their time can be excused for not imaging such a ridiculous thing.

My point might be that when discussing [possible future technologies few people will limit themselves to things that are theoretically possible rather than not excluding possibilities that look ridiculous to them. I'm just as glad to not be in the position of trying to explain a SSME fuel pump to a pre-WWII engineer.

[johndallman]

Originally Posted by Fred Brackin

It's just that they used banks of solid fuel rockets because they were sure that no possible fuel pump could feed a liquid fuel engine fast enough.

The same reason caused initial disbelief when British Intelligence first picked up rumours of the V-2.

[Astromancer]

So, barring information against it, generation starships are possible if problematic. Thus the original question of this thread, "Would 2nd and later generation space habitat colonists be the ones to man generation starships?" is valid.

As the THS setting has highly successful stable space habitats and generation starships are, at base, space habitats with propulsion systems. So the issue of what needs improvement to make generation starships viable is valid in the THS setting.

[Anthony]

Originally Posted by Astromancer

So, barring information against it, generation starships are possible if problematic. Thus the original question of this thread, "Would 2nd and later generation space habitat colonists be the ones to man generation starships?" is valid.

I wouldn't call them star travelers unless they reach the stars. A habitat capable of reaching 0.1% of c and thus reaching nearby stars in a few millennia appears within the described capabilities of THS, and a large self-sustaining habitat is not obviously out of line either (though there's no practical way of testing long term reliability). However, doing so would cost a lot of money and it's hard to come up with a reason for doing so that's sufficiently compelling to tempt anyone with the resources to do it.

[Flyndaran]

Is it really within their capabilities without bankrupting the entire Earth?
Wouldn't a habitat with even a mere thousand people take such a gargantuan multi-stage fusion rocket as to be absurd in any plausible setting sense?
Has anyone built one using THS Spaceships rules?

[Astromancer]

Originally Posted by Flyndaran

Is it really within their capabilities without bankrupting the entire Earth?
Wouldn't a habitat with even a mere thousand people take such a gargantuan multi-stage fusion rocket as to be absurd in any plausible setting sense?
Has anyone built one using THS Spaceships rules?

One of the two starting questions was, "What technologies would need to be improved to make starflight more viable?" I'm not talking Star Trek. It seems to me that the old "They built a generation starship to escape dying Earth!" trope is possible in THS as it stands. What more is needed to allow colonists and worldbuilders to leave the solar system to follow their deam?