Realistic STL Interstellar Missions

[Anders]

Originally Posted by Aldric

I don't think I would like an adventure mid flight. Adventures are supposed to be interesting, sometimes dangerous, you don't want that when you're stuck in a tin can in the void of space.
What you want is uneventful, routine, boring.

Well, you can't always get what you want. Sometimes space is interesting. Sometimes it's terrifying. See my signature for Q's take on space.

[Varyon]

Originally Posted by Anthony

The problem with multi-decade missions is that prestige programs (which is what an interstellar probe mostly is) need to finish soon enough for the people who proposed the mission to reap the benefits -- i.e. it should arrive before the people involved in getting it started retire.

Come up with non-prestige reasons for the proposition and the passing/funding thereof. In a setting where hereditary monarchy is still a big deal, the king’s seventh son may know he can never be king without murdering most of his brothers, but he could become king of a new nation 10 light years away. A combination of intellect, wits, and charisma - as well as his brothers not wanting to risk him going with the “murder” options, and their advisors not wanting him potentially interfering with their own machinations - could lead to popular support and funding. Replace him with a space-obsessed senator who has a good chance of getting his party’s nomination and subsequently winning the presidency in a few years in a democracy. Other options are, of course, possible.

[AlexanderHowl]

Technological innovation in the physical sciences tends to suffer from diminishing returns as the low hanging fruit is plucked by the first generation of researchers and engineers. For example, no one has exceeded the air flight speed record in 15 years, and the manned flight speed record has not been exceeded in over 40 years. The human speed record was set in 1969 by Apollo 10, and no one has gotten within 2 km/s in over 40 years.

When it comes to STL interstellar travel, I do not believe that there will be an economic incentive for the investment required to exceed 0.05c. For example, you could likely send colony expeditions at 0.05c to every system within 50 ly for the cost of developing a 0.10c technology, especially if you have suspended animation. Instead, societies would monitor the colonies from a distance and only launch a new colony mission if they found evidence of a failure.

Of course, it would be relatively easy for a spacecraft to divert when 1+ ly from Earth in order to go to another system. Unless the governments of Earth were willing to waste resources to monitor a spacecraft on a ballistic trajectory, most people would assume a tragedy had occurred when they do not find evidence of the new colony a few years or decades after it was supposed to arrive (light lag is always annoying). Lost colonies will probably be a popular theory concerning missing colony missions.

[Anthony]

Originally Posted by AlexanderHowl

Technological innovation in the physical sciences tends to suffer from diminishing returns as the low hanging fruit is plucked by the first generation of researchers and engineers.

Well, until you come up with a new fundamental scheme. Which we require a couple generations of to have any hope of reaching interstellar speeds.

Incidentally, interstellar ramscoops are not realistic, they're in the category of "sounds good on first look, but the math doesn't work". The drag from the scoop exceeds the thrust of the rocket it's feeding.

Originally Posted by AlexanderHowl

For example, no one has exceeded the air flight speed record in 15 years, and the manned flight speed record has not been exceeded in over 40 years. The human speed record was set in 1969 by Apollo 10, and no one has gotten within 2 km/s in over 40 years.

This has less to do with 'impossible' than 'pointless'.

[ericthered]

Its also worth considering just how large a "system" is. Even if someone gets there before you, It would take a very large group to completely fill up the place you're heading for. And you really shouldn't expect to have the whole planet to yourself in perpetuity anyways.

[Joseph Paul]

Originally Posted by Rupert

Taking that view you'll never leave.

If there's no reason to expect FTL travel to be possible, why would you concern yourself with the possibility of it being invented whilst you were in flight?

It is not just FTL - being able to safely do .5c beats the people that left 200 years ago doing .05c. Those early adopters are actually betting that technology stops and no one will jump their claim. Given our track record on advancing sciences (Look at aerospace - barely off the ground to in orbit in less than 100 years) that is not a great bet.

[David Johnston2]

Originally Posted by Joseph Paul

It is not just FTL - being able to safely do .5c beats the people that left 200 years ago doing .05c. Those early adopters are actually betting that technology stops and no one will jump their claim. Given our track record on advancing sciences (Look at aerospace - barely off the ground to in orbit in less than 100 years) that is not a great bet.

If you're doing this kind of thing the odds are that you haven't experienced any significant improvements in your space propulsion technology over the last century or two.

[Anthony]

Originally Posted by Joseph Paul

It is not just FTL - being able to safely do .5c beats the people that left 200 years ago doing .05c. Those early adopters are actually betting that technology stops and no one will jump their claim. Given our track record on advancing sciences (Look at aerospace - barely off the ground to in orbit in less than 100 years) that is not a great bet.

If you pick a random 200 year period in the last 6,000 years (dawn of civilization), you win in 29 out of 30 of them.

[Joseph Paul]

Originally Posted by AlexanderHowl

<snip>
When it comes to STL interstellar travel, I do not believe that there will be an economic incentive for the investment required to exceed 0.05c. For example, you could likely send colony expeditions at 0.05c to every system within 50 ly for the cost of developing a 0.10c technology, especially if you have suspended animation. Instead, societies would monitor the colonies from a distance and only launch a new colony mission if they found evidence of a failure.
<snip>

Lets unpack that a wee bit.

What is the incentive for anyone to stay alert for the progress of ships that left 2-10 centuries ago? Will the government/civilization that spawned that colonizing effort even exist? At STL speeds there is no real hope for trade so what is the use of tracking anything?

I think that the underlying assumption that extra-solar colonization will be governed by a system wide apparatus is shaky at best. Who cares if more than one group sets out for a destination? Does a group seeking to leave the solar system need approval? The answer - either way - has an awful lot of assumptions about the future in it.

[Anders]

You may also have people who set out because of persecution or religious or ideological zeal. They may feel there's no time to wait for better technology.