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Old 09-11-2019, 08:54 PM   #1
AlexanderHowl
 
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Default Realistic STL Interstellar Missions

STL interstellar missions really only become feasible at TL10, though they requiring staging at that point. The first stage would have to use an advanced nuclear pulse drive to reach 0.01c while the second stage would have to use a ramscoop and fusion rocket to reach 0.05c (a reasonably realistic maximum for a ramscoop plus fusion rocket combination). An additional advantage to a ramscoop is that it can be used to decelerate without engaging the attached fusion drive through pushing against the interstellar medium (though the latter use would require continuous power). The end result is a reasonably efficient and realistic technology for STL interstellar missions.

Using the above combination, a STL interstellar mission would take 10 years to accelerate to cruising speed and 10 years to decelerate from cruising speed. At 0.05c, it takes 20 years to travel 1 ly, so suspended animation is advisable. A short journey of 12.5 ly would take 270 years while a long journey of 50 ly would take 1010 years. While it would be expensive, it would be feasible to spend people to the stars.

So, at what point of the journey would you have a campaign? Would it be at the beginning, before the trip? Would it be during the middle, during a rotation into wakefulness for a year? Would it be at the end, after the trip? What complications would interest you?
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Old 09-11-2019, 10:13 PM   #2
Joseph Paul
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Default Re: Realistic STL Interstellar Missions

It is not feasible to plan for missions that will take more than a few decades to complete because there is an opportunity to gain faster interstellar technology by waiting for the break through in physics and engineering. Going early means that you may very well be leap-frogged by later tech developments and pretty much lose out on having a colony world for what you wanted.

It is not infeasible that governments have changed in the 270-1010 years since the STL launch. They may not recognize the claim put forward (and primary claims are only really recognized if you can show you have physically secured it) or they may have superseded your claim with their own. If tech has advanced while the crew slept they will also be out gunned by whatever the TL difference is. And the colony ship is not built to battle but the advanced tech interloper could very well bring along a couple of ships that are.

And if the front shield of the ship can't take the hit leave it off and up the speed.
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Old 09-11-2019, 11:45 PM   #3
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Default Re: Realistic STL Interstellar Missions

Our velocity has not increased dramatically over the previous 25 years, much less than the proceeding 25 years, due to diminishing returns on investment (11 km/s for Apollo 10 versus 16.2 km/s for New Horizons). Of course, the Parker Solar probe will go much faster than anything else we have created, but it will be cheating, it is just using a particular aspect of its extreme orbit to travel its velocity.

Last edited by AlexanderHowl; 09-11-2019 at 11:54 PM.
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Old 09-12-2019, 06:56 AM   #4
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Default Re: Realistic STL Interstellar Missions

You need more stages unless you're just going to zoom through the target zone...
I'd want to game arrival but pre-departure, journey, etc are all game-able.
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Old 09-12-2019, 07:26 AM   #5
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Default Re: Realistic STL Interstellar Missions

Quote:
Originally Posted by AlexanderHowl View Post
Our velocity has not increased dramatically over the previous 25 years, much less than the proceeding 25 years, due to diminishing returns on investment (11 km/s for Apollo 10 versus 16.2 km/s for New Horizons). Of course, the Parker Solar probe will go much faster than anything else we have created, but it will be cheating, it is just using a particular aspect of its extreme orbit to travel its velocity.
Using the immediate now to counter concerns based on TL progression above TL 9 or 10 over a period of 270 to 1010 years (your numbers) is really kind of lacking in any sort of relevance.
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Old 09-12-2019, 07:40 AM   #6
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Default Re: Realistic STL Interstellar Missions

Quote:
Originally Posted by Joseph Paul View Post
It is not feasible to plan for missions that will take more than a few decades to complete because there is an opportunity to gain faster interstellar technology by waiting for the break through in physics and engineering. Going early means that you may very well be leap-frogged by later tech developments and pretty much lose out on having a colony world for what you wanted.
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?
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Old 09-12-2019, 08:04 AM   #7
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Default Re: Realistic STL Interstellar Missions

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.

That said... It's one thing to cross the ocean, or travel from europe to china on horseback. It's quite different to enter a suspended animation pod for hundreds of years hoping to wake up in another system...
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Old 09-12-2019, 08:44 AM   #8
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Default Re: Realistic STL Interstellar Missions

I do not know. Let us imagine a scenario where you have a sleeper ship with staggered wakeful shifts. Every decade, passengers would wake up for three months to allow medicine to repair the radiation damage caused by cosmic radiation, meaning that 2.5% of the crew and passengers are awake at any given time. 1/3rd of the awake people are recovering from suspended animation, 1/3rd of the awake people are monitoring mission progress, and 1/3rd of the awake people are preparing to reenter suspended animation. Life support comes from aquaponics maintained by the automated systems of the spaceship.

The automated systems wake up the PCs for their tenth scheduled cleansing, one hundred and ten years from Earth and one hundred and ten years from their destination (Epsilon Eridani). An ocean planet suitable for terraforming was discovered in the habitable zone in the 2030s, so Epsilon Eridani become a primary candidate for colonization. There is no one else awake when the PCs wake up though, they simply disappeared without a trace, and now the PCs need to figure out why. What do they do?
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Old 09-12-2019, 10:33 AM   #9
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Default Re: Realistic STL Interstellar Missions

I could see myself playing out either the preparations, the trip, or the arrival. I don't think I'd do all three in the same game, and if I did two, one would be downplayed.

Preparation games appeal to me: there is a LOT to plan, and STL trips are big enough for extensive political wrangling.

in transit games feel small, cozy, and isolated to me. If I ran one, It would focus on a challenge or disaster the crew has to overcome.

And my love of new settlement games is well documented, but I don't think that I'd spend much time in transit or in preparation for such a game.

Of course, I generally like shorter and more contained games, as opposed to sprawling multi-year campaigns.
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Old 09-12-2019, 11:40 AM   #10
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Default Re: Realistic STL Interstellar Missions

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. New Horizons was nine years from launch to Pluto flyby, and is the longest delay from launch to arrival I can find for a planetary probe.
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