Going to space in D&D

[lolcat]

Greetings playground!

I'm part of an awesome campaign in which our characters, due to lack of preparation and the goddess of dice smiling upon us, had a teleport-error which actually landeded us WAY into space (120km above ground). I think for my character, a crafting- and creation-obsessed archivist, this could be a defining moment to make her want to go back up there, but in a more permanent and prepared (and less near-death) way.

So, without involving things like spelljammer, elemental-powered airships or magic item crafting that would take months in-game: What would be the logical, and necessary, steps of discovery and experimentation/creation that could lead to the start of constructing an expandable, permanently inhabited (by mortal creatures that need oxygen/heat/food) space-habitat.
(A little bit more of a background: my character is allies with a few tribes of Kobolds, who essentially get piled on by pretty much everybody groudside and are on the verge of extinction. My characters goal, if possible, (and i'm sure some of you have been thinking that already ;) ) is: space-Kobolds! :D

Thanks and looking forward to your input!

[Anthrowhale]

This thread (http://www.giantitp.com/forums/showthread.php?504415-Terraforming-planetoids-in-a-self-sufficient-fashion) has a related discussion including spells for creating a base in space.

[lolcat]

Thanks! Just in case, for me the link was broken & this (http://www.giantitp.com/forums/showthread.php?504415-Terraforming-planetoids-in-a-self-sufficient-fashion)is a working one.

[Anthrowhale]

Thanks, fixed. Within that thread, this (http://www.giantitp.com/forums/showsinglepost.php?p=21371040&postcount=85) is a particularly relevant post.

[Uncle Pine]

The easy way:

The straightforward way is the Stronghold Builder's Guide. Each stronghold space needs:
1) Chamber of Comfort (keeps the air fresh and the temperature cozy): 7,500 gp
2) The Airtight Wall Augmentation (makes sure you can keep air in): 7,500 gp
3) Flying (In case you end up in the air): 15,000 gp
4) Submersing (In case you end up in the water): 7,500 gp
5) Burrowing (In case you end up underground): 10,000 gp
6) Speed: no specific speed needed, but you do need one: ranges from 5,000 gp for 1/4 of a mile per day mobile to 25,000 gp for 10 miles per hour.
7) Plane Shifting: 25,000 gp per plane shift per day.
8) Teleporting: 50,000 gp per Teleport per day.

At least one exterior wall needs Transparent: 3,000 gp (so you can see out - although you may want to do this to the entire thing, get a hole of hiding installed, and add a ring of invisibility for the pilot (yourself) - to get a stealth flying fortress). You'll also need a source of food and water, but the party cleric should be able to handle that (if not, no big deal - grab a Decanter of Endless Water or an Everfull Basin and either an Everfull Larder or a table of Feasting or a couple of Sustaining Spoons).

Now, you might be able to afford skipping 4, 5, and 7. If you don't mind the place being immobile once it arrives, you can also drop 6. However: To travel any meaningful distance in space, you'll need Teleporting, and you must have Flying so you don't crash the thing into the ground.

Beyond that, it's an exercise in whatever you want. If you're crafty, a Wizard and Cleric team can arrange to make the entire thing for the cost of a few adventures and a few magic items (seriously). Fabricate is good for -50% to -5%; Move Earth is good for -3% to anything on the ground floor; Stone shape or Wood Shape is good for -5% on rooms in stone or wood walled areas; Wall of Stone is good for making decent walls for free (although you can also get those for free by way of picking terrain if you can't make the caster level, and wood walls are free on the first floor anyway - and you're going to fly it away, so...); a Lyre of Building with a good Perform check (Divine Insight) is good for -30%. You're making your stronghold mobile, so that's -5%. You get to pick where you build it, so you make it 17-48 miles from a Small City for another -2%. If it's in a Lawless area, that's good for another -10% (and requires aan adventure or two defending your stronghold while you're building it). Add those up, and you're at a 55% discount before Fabricate. Add a nearby monster lair, and you can get a nice little adventure worth another 5-15% discount. The reason I say before Fabricate? You get Luxury spaces at an additional -50% of cost with that one, putting it at -105% (-110% to -120% with monsters, too). That's right, you're getting paid to make luxury spaces (which offsets the costs of your wondrous architecture). You actually end up making two strongholds with this technique - a sprawling luxury mansion thing (which is stationary), and the flying fortress (which you then take with you). But it costs you nothing but time, daily spell slots, and a few reusable items.

[Palanan]

Originally Posted by Jack_Simth
To travel any meaningful distance in space, you'll need Teleporting, and you must have Flying so you don't crash the thing into the ground.

I would question the teleporting part, especially for the current OP’s needs. OP describes wanting a “space-habitat,” but it doesn’t sound like this needs to be an interplanetary vessel.

Even if the OP wants that eventually, the first step would be an on-orbit structure. Orbital speed for LEO is approximately 17,000 mph, which is one orbit every 90 minutes. If the OP is fine with a structure in this orbit, there’s no need to teleport anywhere else.

[Crichton]

I would question the teleporting part, especially for the current OP’s needs. OP describes wanting a “space-habitat,” but it doesn’t sound like this needs to be an interplanetary vessel.

Even if the OP wants that eventually, the first step would be an on-orbit structure. Orbital speed for LEO is approximately 17,000 mph, which is one orbit every 90 minutes. If the OP is fine with a structure in this orbit, there’s no need to teleport anywhere else.

The problem with teleporting and orbits is that teleporting whatever distance above the surface of the planet doesn't impart the necessary velocity for orbiting. Pretty sure you'd be moving a few hundred meters per second (from standing on the rotating ground) which is effectively standing still when compared to orbital velocities, and would just fall straight bakc down, until you hit the quickly moving-laterally atmosphere. (orbital velocity needed to maintain a 120km orbit is something like 7800 m/s)

It's the reason rockets don't fly straight up, but curve after liftoff, to impart the necessary orbital velocity.


As for doing this in D&D, perhaps a sufficient number of Decanters of Endless Water could provide the thrust you need?

[Palanan]

Originally Posted by Crichton
The problem with teleporting and orbits is that teleporting whatever distance above the surface of the planet doesn't impart the necessary velocity for orbiting.

Agreed, and I didn’t mean to imply that the first step would be to teleport into orbit. Whatever the OP wants to use as a capsule will need to be lifted some other way.

The quote above indicates Flying can be added for 15,000 gp. Ascending at 30 ft/round, the capsule can reach LEO in approximately 59 hours (assuming my math is correct), which is a crawl compared to the eight minutes it takes a modern rocket to reach the same altitude. (This is assuming LEO at 200 miles even, for convenience.)

Once there, I presume Fly will allow you to hover in place, but there’s a lot of delta V required to achieve actual orbit.


Originally Posted by Crichton
As for doing this in D&D, perhaps a sufficient number of Decanters of Endless Water could provide the thrust you need?

In a recent thread about a lunar mission (http://www.giantitp.com/forums/showthread.php?588748-Shoot-for-the-Moon), Tvtyrant shared his design for a steam-exhaust engine using a bank of decanters venting water through a permanent Wall of Fire, as seen here (http://www.giantitp.com/forums/showsinglepost.php?p=23931211&postcount=9).

No idea how to calculate the actual thrust involved, but it’s a first step.

[Blackhawk748]

I feel Minecraft has answered this question for us. And the answer is, a whole lot of metal.

[Falontani]

Elder evils has space rules for 3.5, and they are nasty

[Palanan]

Originally Posted by Falontani
Elder evils has space rules for 3.5, and they are nasty....

How so?

Do they make space travel especially hazardous, i.e. moon is a harsh mistress? Or are they just unhelpful rules?

[TalonOfAnathrax]

Note that by RAW, nothing stops you from simply using Overland Flight to go to space. It'll take a while, but just play a Warforged or something.

Similarly, any Fly spell should allow you to "hang" in space without falling (on earth it already lets you beat gravity).
Seeing as Fly doesn't immediately make you vanish as you fail to keep up with earth's rotation, you should be able to fly straight up and stay in orbit as needed.

[Blackhawk748]

How so?

Do they make space travel especially hazardous, i.e. moon is a harsh mistress? Or are they just unhelpful rules?

Iirc it's a bunch of damage from vacuum, and it hurts. A lot

[Jack_Simth]

I would question the teleporting part, especially for the current OP’s needs. OP describes wanting a “space-habitat,” but it doesn’t sound like this needs to be an interplanetary vessel.
Keep in mind: The thread that was from specifically did want a spaceship.

Even if the OP wants that eventually, the first step would be an on-orbit structure. Orbital speed for LEO is approximately 17,000 mph, which is one orbit every 90 minutes. If the OP is fine with a structure in this orbit, there’s no need to teleport anywhere else.
D&D doesn't do physics well.

If you fly straight up... you're flying in relation to the ground beneath you. Which means you end up in geosynchronous orbit, irrespective of actual height, if the thing your in flies in the face of physics (which a flying stronghold does, by a lot). I suppose if you're high enough that it's actual geosynchronous orbit, magic is no longer necessary to keep it there, at which point it would stick around even if Disjoined or whatever. So that's a nice bonus, at least.

[lolcat]

The problem is, i do not think the rotational speed of the earths surface is enough to keep you in orbit if you are 120 km up. Comparing it i.e. to the speed of the ISS, we'd fall short by a factor of almost 20.
Since i love the idea of making my DM think through orbital mechanics, does anybody have an idea how to actually achieve that dV and get an object fast enough to stay up there without magic?
(in the case of the ISS that would be 7,66 km/s or 17,130 mph)

Thanks! :)

[Crake]

You can just orbit at a higher altitude. The higher up you are, the slower you need to orbit. That said, if the structure has a supernatural flight speed, then it wouldn't need to orbit at all, it could quite literally just hover above the surface of the planet at whatever altitude is designated. Whether or not the earth rotates underneath it, or it holds steady to it's relative position is something your DM will need to work out.

[lolcat]

Alright, i just unearthed some of my slumbering engineering knowledge and came up with the following, what would you think about that?

The spell boreal wind creates a strong, large-volume windburst. As i see it it creates a 20*20*440 ft. volume of air. Just spitballing it, meaning ignoring higher air density due to temperature etc, that meas it creates a gust of wind about 22 m/s fast over a 36 m² area and 134 meter length at minimum.
To go from 22 m/s to about 7,6 km/s speed of expelled air, we'd need to essentially build a funnel-like construction with a narrow enough end so that the expelling of air increases its speed to 7,6 km/s, which should be just about 20 cm in diameter if my math doesn't leave me.
So i could build a solid metal "bottle", on the bottom of which a permanently active rune of that spell churns along, with an appropriately sized nozzle.

While it isn't non-magical it's at least a well fortifiable system that would need extensive damage or ethereal-shenanigans to have someone be able to disable/dispel it. How solid that thing needs to be to be able to take km/second winds is the next question however.... :D

[Mato]

So, without involving things like spelljammer, elemental-powered airships or magic item crafting that would take months in-game: What would be the logical, and necessary, steps of discovery and experimentation/creation that could lead to the start of constructing an expandable, permanently inhabited (by mortal creatures that need oxygen/heat/food) space-habitat.You could have them go on a small side quest to fulfill their desire. The DMG has a few examples.

Perhaps a starship from a much more highly advanced civilization landed or crashed in the campaign world. ... Or perhaps the advanced civilization was native to the campaign world but is now long gone ... you could decide that many of the strange creatures found in the world result from ancient genetic engineering. Finally, perhaps members of some advanced civilization have come to the campaign world with their advanced science and now serve as patrons or overlords. They dole out their technology in small doses to those who serve them well.

Also to cut down on some of the houserules, and later changes as you realize you may need more, you can use Modern's SRD for some official ones. Like different environments & radiation (http://www.d20resources.com/future.d20.srd/environments/).

The d20 MODERN® Roleplaying Game, a D&D-compatible roleplaying game for present-day adventures, contains a much more extensive treatment of firearms and other high-tech gear.

[Jowgen]

Loving that people remember my old terraforming thread :smallbiggrin:


Also to cut down on some of the houserules, and later changes as you realize you may need more, you can use Modern's SRD for some official ones. Like different environments & radiation (http://www.d20resources.com/future.d20.srd/environments/).

Radiation has two rulesets to my knowledge, one being Sickstone (http://archive.wizards.com/default.asp?x=dnd/fw/20021228a), the other being from a actual bloody nuclear reaction in the "Return to the Temple of the Frog" adventure. Both deal con damage, the reactor actually has a cumulative chance to give you an x-men style mutation.

There is also a 3.5 example of an actual illithid spelljammer in 3.5 setting in the "flow of fresh brains" adventure, where the party portals up to a disabled ship, and I believe it has rules for what happens if you get sucked into space. Personally though, I'd stick with the Elder Evils atropus set of rules.

Now, while a lot of good suggestions have been made regarding solutions, I'd like suggest something about the process of developing the program.

First, your character would study the conditions that come with increasing altitude. Build prototypes of different units designed to get you into and keep you alive in orbit, then test them by like sending up some monkeys or whatever, with some measuring equipment. Once you know what sorta environment variables you're dealing with, then he can start refining solutions for atmosphere, pressure, temperature, radiation protection, long term effects of low gravity, sustenance, base maintenance, and of course transport of materials.

To keep with the whole crafting-archivist thing that wants to go a little less magic-heavy, I think the best thing to work towards would be to make a space elevator.

D&D has materials that have more than enough tensile strenght/mass to make that workable. If you can get yourself a lift, then working on slowly expanding the base and making a big space-island dome thing that you might eventually work into an actual space port will be much simpler.

[Palanan]

Originally Posted by Jowgen
…I think the best thing to work towards would be to make a space elevator.

I was going to suggest this earlier, but from the OP’s comments the kobolds are trying to find a safe haven, and a space elevator would be a conduit for their enemies rather than a barrier.

Also, a comparatively tiny habitat in orbit would be easy to hide, but a space elevator is pretty much a giant line drawn from the surface straight to the community that’s trying to escape the surface. Not the best way to stay out of sight.

I think a space elevator is an awesome concept in its own right, and deserving of development, but not sure if it’s the best approach for this particular situation. But the OP knows his situation best (and that of the allied kobolds) and might have a different view.

[unseenmage]

Word to the wise, teleporting materials becomes much easier if they're hit with Shrink Item then Animate Objects first.

Also of note is the Attune Gem feat from (I think) Magic of Faerun. Basically let's you make any arcane spell into a Portable contingent spell.

Good for automating space base construction by planning and casting on the ground then teleporting someone up there with a handful of preplanned magical if-then statements which result in Permanencied Wall of Force construction.

Another idea if Fabricate on some Riverine (St) to make astronaut statues then Minor Servitor (SS) to turn them into undamagable severe environment workers.