Interstellar Operations Open Beta Test: Solar System Generation: Discussion

[kato]

separate cardstock?

Separate would be ideal. Perhaps with other tables on the back. I do a lot of moving back and forth through the pdf when looking up some star data in later calculations (e.g. luminosity).

[monbvol]

Aye something you can have off to the side would be great.  Having printed out the PDF myself has taken the rules from nigh impossible to merely daunting thanks to all the flipping back and forth it has saved.  Plus having found some of those equations in my more thorough reading that I skimmed over previously I'm now having to correct myself about the supposedly extranious data in the table.  Still I'd love to see it on a separate cardstock for the hard copy.

All said and done I'll be glad when someone manages to automate the process because I just keep making too many mistakes.

[specter]

At long last...

Attached are the updated table and the corresponding description. The description is probably incomplete and some details require more explanations. Feel free to ask if/when something does not make sense...

For the record, I was ordered at editorial gun point ;) to give a faint chance for habitability on the Primary Stats Table to bright stars (hence the very high penalties in A and B-class stars. Most of my drafts had a cut-off ("Not habitable") for stars with lives too short to really get a good ecosystem (or even planets) going.

Okay, let's try to save your life.  ;)
I have replaced the N/A entries in the habitability columns of my table with actual values even if there is some argument against habitability. This way you can allow habitable planets around A and B types. In case that you need an excuse/explanation, you could go for more massive planets. Their higher gravity allows to accumulate a more dense atmosphere. This way, the ionosphere may not reach down to the surface while the escape velocity would be to high to blow away the atmosphere. The highly ionized atmosphere layers would hamper radio communications, probably make flying through it problematic and radiation levels on some higher mountains may be deadly. As an alternative, a deep ocean would block radiation from reaching sea life. Fluffwise both methods could turn out interesting for players... Anyway, short stellar lifetimes might not be as problematic as we expect. According to Kaltenegger et al.(2009), evolution to higher lifeforms could proceed on timescales of 10 million years. Therefore, the lifetime of A stars should not be a problem.

Another idea about some other construction site:
I presume, the level of detail is already too high? If not, one could approximate formation rates of ice asteroids and their subsequent migration into the inner system. This would allow to calculate probabilities of arid and water-rich planets depending on the spectral type of their host star. As I have mentioned before, one can expect more arid planets around more massive stars while ocean-covered planets could be more likely around lower mass stars.

Furthermore, it could be interesting to flesh out some details on planetary migration. A few details about this are already explained in the description.

Interested?

[Daryk]

...According to Kaltenegger et al.(2009), evolution to higher lifeforms could proceed on timescales of 10 million years...

I haven't yet found that particular article, but one I found from 2010 talked about "the origin of life on Earth" on that timescale, not "higher lifeforms".  The specific mention is on page 3, paragraph 2.1.2 of the "preview" available on that site.

EDIT: Here's a second Kaltenegger (et al.) article from 2010 (assuming I'm reading the notation correctly).  She uses the same language regarding origin of life on page 8, paragraph 5.1.3.

[idea weenie]

One thing might be a complete redo of the USIIR codes.  Instead of as follows:
(i.e. for Industrial output)
A - High output
B - Good output
C - Limited output
D - Negligible output
F - No output

It would be:
A - No output
B - Negligible output
C - Limited output
D - Good output
E - High output

This way you don't get cases (like Earth in Battletech) where it is listed as A (Advanced) - A - A - A - A.  Using this system, you have extra letters to work with, so Earth would be F - E - E - E - E.

By having A represent effectively nothing (or having to import the necessities) you avoid trapping yourself at the beginning of the alphabet.  It would allow for super population worlds, worlds with extremely high industry, farming planets

[wwwjason]

I had a thought while reading Interstellar Expeditions: are there plans to include information on terraforming planets? For example, how much time might be needed to bring a planet up one step on the HABITABLE PLANET FEATURES TABLE on page 14, what kind of cost, equipment, etc. are needed, and what are possible complications/failures that might arise during the process?

[specter]

I've appended a revised plot for the different forming and habitability zones that also includes various other curves corresponding to quantities mentioned in the decription pdf.

Some remarks with respect to this figure:
- For O and early B stars, the habitability zone lies outside of the effective planet formation region.
- For mid-B to mid-A stars, the habitability zone is very close to the effective iceline, which would increase the rate of habitable moons in orbit of gas giants.
- Note that most of the low-mass stars are tidally locked.

And one more suggestion for the rules: It is easy to create a table that lists minimum planetary radii that are necessary to maintain critical species (w.r.t. habitability) in the atmospheres.
The background of this is simply the fact that planets require a minimum radius/mass for a given surface temperature in order to have thermal gas velocities below the escape velocity.
For example, this allows to distinguish planets like Earth with stable oceans and atmospheres and planets like Mars which are uncapable of maintaining hydrogen in their atmosphere, hence, lack liquid water. What do you think?

I haven't yet found that particular article, ...

Good catch.
Oh well, one should not argue from memory but look once more into the reference before quoting, especially when tired...  :-[  (As a sidenote, the article I referred to can be downloaded at http://arxiv.org/abs/0906.0378)

Not that I'm a big fan of life on a planet orbiting an A star but if the Cray's gunpoint problem needs to be resolved we should at least try come up with a reasonable explanation to make the best out of it:
"origin of life" is not exactly a precise expression. Does it refer to organic chemistry only, to protozoa or multicellular life? The lifetime of a mid-type A star is around 50 times those 10 million years.
Anyway, higher life, whatever we define this means, developed on Earth from protozoa on a timescale of 1...2 billion years. There is not a huge difference to the age of an old A type star. Merely a factor of 2...4, i.e., nothing on logarithmic scales that are typical for chemical and biological processes. It is not unthinkable that other environments can accelerate evolution. For instance, the higher ionization rate of atmospheres in the habitable zone of A stars could result in higher numbers of free radicals in the gas which would enhance mutation rates. Of course not necessarily in a constructive way but without simulations we can hardly tell...   8) ;)

[Daryk]

The article I found looks like the revision of the original 2009 paper.  Maybe Kaltenegger changed her mind?  Either way, your chart is great!

[specter]

The article I found looks like the revision of the original 2009 paper.  Maybe Kaltenegger changed her mind?

The two are likely different drafts of the same publication. It is usual to upload a paper on arxiv.org as soon as it has been written in order to get results to the community as soon as possible. However, the official publication in a scientific magazine is done following a peer review process that can strongly alter the content of a publication. Review can take between weeks and months and only after this one can technically trust a paper's content. For the given reason, some papers that appear on arxiv.org will never be published officially.

[cray]

I'm late to this party, but will hopefully be able to read through the pdf over the next couple of days.  Is there a close date for feedback?

I'm hoping to have a revised edition back to the bosses by the end of next week. If you don't make me re-write large tracts of the rules, then you've got until at least the end of Sunday.

Of course, by then another chapter is going up for public comment that I'm responsible for, so that'll be some multi-tasking.

One thing might be a complete redo of the USIIR codes.

Unfortunately, Interstellar Operations is not the place to retcon codes in use for nearly 10 years across planetary stats in House Handbooks, Masters & Minions, A Time of War Companion, etc., or to revise the explanations for USILR codes that been described in many sourcebooks, A Time of War, etc. You might bounce the idea off The Line Developers, though, in the Ask the Line Developers forum and see what they think of a large retcon.

I had a thought while reading Interstellar Expeditions: are there plans to include information on terraforming planets? For example, how much time might be needed to bring a planet up one step on the HABITABLE PLANET FEATURES TABLE on page 14, what kind of cost, equipment, etc. are needed, and what are possible complications/failures that might arise during the process?

Now that's an interesting idea. BattleTech seems to be very quick about terraforming, being able to terraform Venus and Mars to basic habitability in about 100-150 years. (Reasonably, other projects would generally be in terms of 25 to 75 years.) However, JHS:Terra also notes they were some of the most epic engineering endeavors by mankind (the tonnage of nitrogen, water, and calcium needed to be delivered to Mars and Venus is best described with exponents or fractions of Titan's mass) and most other terraforming efforts around the Inner Sphere are smaller.

I think the places the idea would break down is costs, logistics (tonnages of equipment required), and trying to set numbers to the tonnages of water and oxygen or nitrogen to be added (or removed) from planets. BattleTech's economics are not set up to handle trillion- or quadrillion-CB projects. Its merchant stellaris is in shambles for most common eras of play (so importing giant "atmosphere processors" or other mega-engineering equipment is hard). Existing, well-described space transports (DropShips) are poorly suited for moving teratons of water or other useful terraforming materials.

In short, terraforming rules open several cans of worms. It's easier to let players designate a planet as having been terraformed, particularly when the system generation rules note the star or planet is unlikely to pass a habitability roll.

And one more suggestion for the rules: It is easy to create a table that lists minimum planetary radii that are necessary to maintain critical species (w.r.t. habitability) in the atmospheres.
The background of this is simply the fact that planets require a minimum radius/mass for a given surface temperature in order to have thermal gas velocities below the escape velocity.

I already factored escape velocity into habitability and atmosphere thickness. Did you want a different, more detailed approach than just escape velocity?

[Daryk]

I'm hoping to have a revised edition back to the bosses by the end of next week. If you don't make me re-write large tracts of the rules, then you've got until at least the end of Sunday.

Of course, by then another chapter is going up for public comment that I'm responsible for, so that'll be some multi-tasking.
...

Thanks, Cray!  I should definitely have something by then, probably more for the errata thread than this one, so no worries on re-writing large tracts of rules.  My last astrophysics course was almost twenty years ago now, but most of what specter (and Kaltenegger) was talking about is still intelligible.

[wwwjason]

Now that's an interesting idea. BattleTech seems to be very quick about terraforming, being able to terraform Venus and Mars to basic habitability in about 100-150 years. (Reasonably, other projects would generally be in terms of 25 to 75 years.) However, JHS:Terra also notes they were some of the most epic engineering endeavors by mankind (the tonnage of nitrogen, water, and calcium needed to be delivered to Mars and Venus is best described with exponents or fractions of Titan's mass) and most other terraforming efforts around the Inner Sphere are smaller.

I think the places the idea would break down is costs, logistics (tonnages of equipment required), and trying to set numbers to the tonnages of water and oxygen or nitrogen to be added (or removed) from planets. BattleTech's economics are not set up to handle trillion- or quadrillion-CB projects. Its merchant stellaris is in shambles for most common eras of play (so importing giant "atmosphere processors" or other mega-engineering equipment is hard). Existing, well-described space transports (DropShips) are poorly suited for moving teratons of water or other useful terraforming materials.

In short, terraforming rules open several cans of worms. It's easier to let players designate a planet as having been terraformed, particularly when the system generation rules note the star or planet is unlikely to pass a habitability roll.

I agree that mega-scale engineering would be impractical, and even implausible for non-Terran Hegemony terraforming projects. What I had in mind was more along Robert Zubrin's In-Situ approach for propellant, but on an atmospheric scale using large, automated dropships converted into atmospheric processors. Here would be the assumptions/requirements:

• The planet has the atmospheric and chemical prerequisites for terraforming, i.e., water, organics, presence of atmosphere or it's precursor (e.g., frozen in the regolith).
• The terraforming processes are able to act on the atmosphere via a runaway greenhouse effect, introduction of a synthetic biological agent (e.g., algae seeded across portions of the planet for O2 production), etc.
• Nothing at any large scale in imported - any water, gasses, etc. are either already on the planet, or can be imported from within the system (comets for water and organics, etc.)

And for the actual process: The idea is that there are many star systems with uninhabited worlds that were never compatible with terraforming, but a few fell into the narrow range that were technically and economically feasible to terraform. For these, a jumpship with Mule-sized atmospheric processor drones arrives in system, lands at strategic points on the planet, and cranks on the atmosphere for 20-50 years. Meanwhile, aerostat drones seed the planet with algae and microorganisms to establish minimally habitable pressure, temperature, and O2 partial pressure (and locking up any toxins). Once they're done, the drones gather up, dock with their JS, and move on to the next scheduled planet.

If this line of thinking sounds interesting, I'd be happy to take a swing at a roll-table for terraforming planets. This could also be an interesting IE and RPG thread (if these terraforming drones had a long list of scheduled planets, are they still roving the deep periphery?).

[cray]

Thanks, Cray!  I should definitely have something by then, probably more for the errata thread than this one, so no worries on re-writing large tracts of rules.  My last astrophysics course was almost twenty years ago now, but most of what specter (and Kaltenegger) was talking about is still intelligible.

Before posting to errata (except the most blatant formatting / spelling errors), please share your findings here. Sometimes there are reasons behind the oddities.

[Daryk]

Will do!

[cray]

Terraforming is already addressed in Era Report: 2750. Did you want something other than those guidelines?

[wwwjason]

Terraforming is already addressed in Era Report: 2750. Did you want something other than those guidelines?

IIRC, ER:2750 covered the terraforming of Mars and Venus, and hinted at the mass-scale terraforming of other planets. There was no description on how the DoME did this at a (Inner Sphere + Periphery) mass scale, much less as far out as the peripheral and deep periphery (as implied in IE).

At a minimum, some rule for modification of the habitability of a rolled system would help make IO applicable to the Star League eras. Preferabley, some depth on how terraformation of so many planets, over a relatively short timeframe, was accomplished.

I also thing this will enrich the Solar System Generation rules, especially for lost worlds.

[Blacknova]

Perhaps inserting a fiction piece in IO from the point of view of a DoME engineer would be a good way to do it without creating rules for it.

[Daryk]

Cray, I've just started my detailed read through, but I must say the scientist in me cheers at the carefully crafted caveats in the language.  The gamer in me cries, however.  I think there's a happy medium that I'll shoot for in my recommendations.

[cray]

Cray, I've just started my detailed read through, but I must say the scientist in me cheers at the carefully crafted caveats in the language.  The gamer in me cries, however.  I think there's a happy medium that I'll shoot for in my recommendations.

When the gamer in you is weeping, please read the ATOW:Companion, which has the simplified system generation rules. IntOps is meant to be the science-heavy, detailed version of the system generation rules.

[Daryk]

Fortunately, I picked that up at the same time as the open beta.  I'll definitely compare the two before submitting my comments.  Thanks again, cray!

[monbvol]

I've noticed something but I'm pretty sure it is an intentional choice and thus I'm commenting here instead of the Errata Thread.

If I'm reading everything right a M6V star can never have a planet in the life zone unless you monkey with the life zone.

[Korzon77]

quoted from the ISP thread:

On the IO operations, I think that the far colony numbers may be low-- and high.  That is to say, that I would expect that a colony world more than 1500 LY away, and beyond any support has either prospered, or become a completely failed colony especially if its old. A borderline colony would have too many opportunities for events to push them over to the level of non-viability.

I'm not certain how to work this--one possibility might just be a mention that the older a colony is, the more likely it will be to diverge (in either direction) from the norm, either being non-viable or larger than average.

Another suggestion I have is to include some comment about population growth rates (depending on deadline and wordcount permitting). I don't know if the mathematical formula would be wise (there are a wealth of online population calculators) but a point mentioning that especially on garden worlds, even small starting populations can increase radically due to natural growth over the course of centuries might be a good idea.

[cray]

If I'm reading everything right a M6V star can never have a planet in the life zone unless you monkey with the life zone.

There's some issues with the initial planet placements. They'll be fiddled to get more orbits in the life zone.

[monbvol]

As far as I can tell that is the only outlier.

[Scotty]

As far as I can tell that is the only outlier.

It is; the previous discussion is on the first or second page.

By chance, my first system came up M6V, and I pointed it out.

[Daryk]

Cray, my comments are attached.  I suspect many of them have already been noted here or (more likely) in the errata thread.  Given the Companion simplified system, I limited my edits of what I thought was overly cautious language to the most extreme examples.  I hope these help.  If I was unclear (or outright wrong) about anything, please let me know.

[monbvol]

Feldergarb.  :P

Though I don't mind the idea of such possibilities.  Could make for an interesting terraforming project hook.

[Vulp]

I went through these rules and generated a system and habitable planet.  I really appreciated the level of detail in the rules as well as the science-centric approach.  For my non-canon version of the New Hope system, I generated a habitable planet that had a High Pressure atmosphere.  Are there any guidelines for how many bars of atmosphere this represents?  With the level of information in the doc it is possible to develop a great deal of detail about a planet, including temperature bands and continents, so I found the lack of detail on habitable atmospheres a bit odd.

Currently there is only a cross-ref to TacOps, which contains the effects on aircraft movement and drop rates, but it would be great to have a little bit of additional detail on what exactly is meant by High / Low atmospheric pressure.  There is a brief mention of Earth's historic atmosphere as a good model for atmospheres mentioned on page 13.  This is a great source of info (in my generated system, I think I'd want to up the CO2 to increase the overall density -- the world temperature is Very Hot, so this is consistent), but the real question is how high is "High"?  We know that a "Very High" result is inhabitable.  What are appropriate ranges for each of the results in the table titled "ATMOSPHERIC PRESSURE AND HABITABILITY TABLE"?

Overall very impressed with this set of rules, looking forward to the finished product.

[specter]

I already factored escape velocity into habitability and atmosphere thickness. Did you want a different, more detailed approach than just escape velocity?

Your approach is alright. I only wondered if you were interested to supplement it (if page space permits) with respect to atmospheric composition.

One could list required minimum radii for planets in order to have a long-term stable atmosphere of a certain composition, e.g., atmosphere that contain O_2.

Since this is mostly interesting for planets in the habitable zone, the surface temperature range is well constrained. Likewise, the density of terrestrials is well constrained. Roughly, only the planetary radius of the planet determines the balance between thermal gas velocity and gravity.

The higher the mass of a certain gas molecule, the lower is its thermal velocity, i.e., heavier molecules are less likely to exceed escape velocity.

For instance, a terrestrial (Rho_Earth, T_Earth) requires at least a radius of ~3000km in order to maintain some O_2 in its atmosphere over longer timescales. Therefore, Mars is not even worth terraforming as it would quickly lose all atmospheric oxygen for a second time.

A similar terrestrial planet as above, would have to have a radius of ~10000km to maintain an atmosphere of H_2. Likewise a Jovian (1g/cm^3, 100K) requires a minimum radius of ~15000km in order to avoid thermal vaporization.

Depending on your preferences and page space allocation one could make a simple list of minimum planet radii for different critical molecules or even create a table to consider the dependence on surface temperatures.

[monbvol]

Having finally gotten through a run without making any mistakes of such severity that I had to abandon and start over I will say this does absolutely need a cheat sheet with all the calculations on it somewhere.  It would have saved me a lot of trouble knowing before hand the variables that would need to be repeated in other equations that needed calculations to determine the value of before hand.