PDA

View Full Version : Making a spaceship



Jayngfet
2009-05-24, 11:01 PM
So for a game I'm running I was wondering what spells would be needed to build a spaceship:

Animate object,Fly(movement)

Teleport, greater teleport(hyperdrive, "beaming up" to get to the actual planet)

Expedious retreat, plane shift (to shadow)(flying faster)

Magic missile, fireball(defenses)

Know direction, scrying(navigation)

create food and water(food synthesyser)

Any others?

Garian
2009-05-24, 11:34 PM
invisibility - cloaking device
something to survive spaces cold climate. I know there is a spell for this

Know direction is no good. It tells you what direction is north. There is no North in space.

Jayngfet
2009-05-24, 11:35 PM
Do you mean endure elements?

TheCountAlucard
2009-05-24, 11:36 PM
Magic missile, fireball(defenses)Since Magic Missile doesn't deal damage to objects, I'd recommend an Orb spell over it. Or Disintegration.

create food and water(food synthesyser)And Prestidigitation if you, y'know, want the food to taste good.

Garian
2009-05-24, 11:38 PM
Do you mean endure elements?

Exactly, thanks

Jayngfet
2009-05-24, 11:40 PM
invisibility - cloaking device
something to survive spaces cold climate. I know there is a spell for this

Know direction is no good. It tells you what direction is north. There is no North in space.

Perhaps it would point to the nearest celestial object that HAS a north?

elliott20
2009-05-24, 11:41 PM
force wall would probably be necessary too for air pressure purposes.

some divination spells to go with the on board navigation system would probably be good too.

Mando Knight
2009-05-24, 11:55 PM
Status (to keep track of ship systems)
Tongues, Message (with scrying, communication systems)
Telepathic Bond (for communications within the ship)

Draco Ignifer
2009-05-25, 12:11 AM
Nonmagical attacks have infinite range in space, and space has line of sight limited only by whether or not you can detect what you're seeing. Magic, on the other hand, is arbitrarily limited to 1,200 feet, or 2,400 if you enlarge, and you probably won't get that. Magical attacks, then, are actually inferior to a distance ballista, or even a normal longbow, because you can stay out of range and pepper your enemy to death. If you use the 10 range increments thing as an absolute limit anyway, distance ballista still win up until level 20.

This, of course, ignores the fact that modern weapons are accurate to much further than that, ultratech are probably even more accurate, and most space travelers will be ultratech. As DM, it is within your power to rule that there is no ultratech, and hence no other spacecraft that will obliterate this magical contraption without it ever being able to fight back.

Also, movement is going to take for-freaking-EVER at fly's speed, even when just talking intra-system, intra-planet, or even intra-continent. It's going to have to rely 100% on teleports for anything other than maneuvering, so consider carefully how to handle that.

imp_fireball
2009-05-25, 12:16 AM
You could always create epic custom spell feats that extend the range of certain spells. Or maybe the spells would be entirely customized with extended ranges.

I'd also make for spells that enhance vision (improve touch attack or allow LOS).

Sstoopidtallkid
2009-05-25, 12:26 AM
Generally, the best bet for propulsion is Decanters of Endless Water. It won't let you maneuver well, but constant acceleration is better than any arbitrary limit on speed less than a Chuck Unit.

For armor, Adamntite is nice(but expensive). If you're more economical, you could go Wall of Steel with an item that constantly repairs damage, then hope you're never badly hulled. A Bottle of Air should be enough to compensate for leakage over time, or just equip each crew member with a Necklace of Adaptation. I'd say both, so they can take on passengers and plants with less worry. Heat/Chill Metal should function for enviromental controls, but with the Necklaces isn't necessary. Cleric with a full stock of scrolls and a CLW trap for a medbay. There is also no reason to make it able to operate in-atmo, that's what the Greater Teleport trap is for.

I'd say look at Stronghold Bulder's guide for pricing and assembely of some stuff, and of course if someone could track down Tippy's design that would be awesome, too.

NecroRebel
2009-05-25, 12:32 AM
Tippy and some others were considering something like this a while back. What I can remember them coming up with:

Make the ship adamantine, perhaps with an inner bulkhead of lead depending on whether or not the denser material also has lead's radiation-blocking properties. This allows you to survive impacts with other objects (micrometeors and such), due to the high hardness of adamantine, and outer space's omnipresent hard radiation due to the lead.

Put atmosphere valves, dozens of very small ones, around the outside of the vessel, designed so that they open, venting atmosphere, if the pressure gets over ~14 psi (1 atmosphere) and close if the pressure gets below that point. Then, immerse open Bottles of Air in a tub of water - the Bottles only produce air if they're in an airless environment, hence the water - which will provide the whole ship with a breathable atmosphere, while the valves willprevent the atmosphere level from building past comfortable levels.

Have auto-resetting and activating Endure Elements traps scattered throughout the ship - you want to be damned sure that you get everyone to pass through the traps at least once per day. This will protect the crew from the temperature extremes of space to a certain extent, though you may also want to take advantage of Wondrous Architecture to climate-control the place as well.

For thrust, Tippy suggested Decanters of Endless Water. Basic magic is, simply put, too slow to make even intraplanetary travel practical, much less interplanetary or interstellar. While Greater Teleporting the ship will work for distances greater than about 1/4 AU, it doesn't really work for orbits, and isn't really practical for shorter distances. However, hundreds of Decanters can act as actual rockets if set to geyser, putting out a couple pounds of pressure each if I remember the math right.

As far as weapons go, you're going to be at essentially point-blank range with anything you can manage, just in terms of perception issues. You can constantly scan random patches of sky with scrying or other detection spells, but it just isn't enough to pick out other ships, which are also probably made of adamantine which very well might be matte grey or black and thus impossible to see against starfields. However, point-blank, in space, is several miles, and no magic spells or magic weapons can reach that far out. As such, your "weapons system" should actually be golems that can greater teleport to within range, and then they'll rip enemies apart. Essentially, combat drones.



Edit: I give you the thread in question. (http://www.giantitp.com/forums/showthread.php?t=86964&highlight=spaceship)

JeminiZero
2009-05-25, 04:23 AM
I'm once postulated that an easy way to build a spaceship was to use a custom item that permanently manifests a telekinetic sphere (http://www.d20srd.org/srd/spells/telekineticSphere.htm). Its indestructable, precisely maneuvreble, and comes with automatic slowfall.

For faster long distance movement, various means are possible, including decanters of endless water thrusters (since the text does not say that it cannot be moved externally and in fact emphasizes that things inside are 1/16th normal weight). Just add bag of holding to extend the space/weight limitations, and you're good to go.

AgentPaper
2009-05-25, 04:51 AM
something to survive spaces cold climate. I know there is a spell for this

Space is not cold.

Bags of holding are good for cargo, but I would use portable holes for rooms, since the entrance is larger and the area is static. Also, since the portable hole is in another dimension, gravity will be normal there, so you don't have to worry about muscle/bone decay.

Halaster
2009-05-25, 06:20 AM
Like Agent Paper said, space is not cold. The ship should lose little warmth to space, so you would probably be better served by lighting a fire in the ship (particularly if air is not an issue) or using an item that radiates heat (e. g. through a Heat Metal spell).

AgentPaper
2009-05-25, 07:01 AM
Like Agent Paper said, space is not cold. The ship should lose little warmth to space, so you would probably be better served by lighting a fire in the ship (particularly if air is not an issue) or using an item that radiates heat (e. g. through a Heat Metal spell).

Actually, the ship getting too hot is the only issue you're likely to run into, outside of atmosphere. There's no real way to dissipate heat inside a ship, so even just body heat will eventually make things uncomfortable, even if you don't have huge engines like a normal space ship would. Still, without said engines, a trap of frost or some such that you spring every once in a while would be more than enough.

Ravens_cry
2009-05-25, 07:25 AM
Like Agent Paper said, space is not cold. The ship should lose little warmth to space, so you would probably be better served by lighting a fire in the ship (particularly if air is not an issue) or using an item that radiates heat (e. g. through a Heat Metal spell).
Then you have to worry about heat build up, as a Thermos works both ways.
Spraying the outside of the ship with water from (yet another) endless flask would cause the water to absorb the heat, and then sublimate, taking the heat away with it.

hewhosaysfish
2009-05-25, 07:49 AM
There's no real way to dissipate heat inside a ship, so even just body heat will eventually make things uncomfortable, even if you don't have huge engines like a normal space ship would. Still, without said engines, a trap of frost or some such that you spring every once in a while would be more than enough.

We could put our rockets (Decanter's) at the front of the ship rather than the back, run the high-pressure water through pipes through the centre of the ship and shoot it out the back.
Combined coolant/propellant system.
The downside is, if your pipes spring a leak then the interior of your ship will get very wet, very quickly. I suppose this is only an inconvenience if you're using Necklaces of Adaptation and pressure-release valves. Of course, most of the thrust from the ruputured pipes would be wasted through these valves so you would have to have some thrusters that weren't being used for cooling.

Alternatively you could run the pipes around the outside of the ship: that would reduce the probability that a leak would be sprung into ships interior (instead leaking into space) but would reduce its cooling ability and increase the chances of it being damaged by an attack.

Radar
2009-05-25, 08:30 AM
Actually, the ship getting too hot is the only issue you're likely to run into, outside of atmosphere. There's no real way to dissipate heat inside a ship, so even just body heat will eventually make things uncomfortable, even if you don't have huge engines like a normal space ship would. Still, without said engines, a trap of frost or some such that you spring every once in a while would be more than enough.
Two words: thermal radiation. A human body emites 100W of radiation. A big spaceship will emit proportionally more, since it has to keep about the same temperature (300K) to be habitable. And space is cold - IRL it's less then 3K. In fantasy settings it can vary, but it has to be significantly lower then life supporting temperature. Otherwise planets couldn't dissipate energy gained from a local sun.

As for the long distance travel: Gate - hop to some other dimension and then hop back in a different place. Even with Decanters of Endless Water and assumption that there is no limit to velocity (probably proved by Chuck) it's still not accelerating fast enough to be usable for space travel (even through the Plane of Shadow).

bosssmiley
2009-05-25, 08:31 AM
Take one medieval sailing ship, add spelljammer helm (3E versions are in Dungeon #92, 4E versions in the 4E MotP or here (http://www.thepiazza.org.uk/bb/viewtopic.php?f=2&p=16919)). Ride the solar winds as a feared stellar corsair. Job done.

Related reading (http://www.giantitp.com/forums/showpost.php?p=4396752&postcount=33)

Thrust? Reaction mass? Explosive decompression? Hah! Grubbian physics laughs at your puny gurlyman considerations...

(Or there's always the excessively detailed and over-elaborate section-by-section flying ship generation system from "Champions of Mystara"...)

Yuki Akuma
2009-05-25, 08:42 AM
Two words: thermal radiation. A human body emites 100W of radiation. A big spaceship will emit proportionally more, since it has to keep about the same temperature (300K) to be habitable. And space is cold - IRL it's less then 3K. In fantasy settings it can vary, but it has to be significantly lower then life supporting temperature. Otherwise planets couldn't dissipate energy gained from a local sun.

No space is not cold. There's nothing out there to be cold. Radiation is a lot less efficient than conduction, so the heat loss will be minimal for something with such a tiny surface area.

Planets dissipate heat well because they are ****ing massive and also because they only actually receive any energy on one half at a time.

Chiron
2009-05-25, 08:44 AM
*goes digging*

I actually did a little work on something like this once. But I didn't like the feel of what the finished product was turning out to be...

First off I started off with an organic body made out of wood basically directly stolen from a device Stephen Baxter has used more than once (http://en.wikipedia.org/wiki/Raft_(novel)) (it's also in 'Space (http://en.wikipedia.org/wiki/Manifold:_Space)'). Also: Kevin J. Andersen uses it in the 'Saga of Seven Suns (http://en.wikipedia.org/wiki/Saga_of_seven_suns)' too (just haven't gotten to that book yet.)

The ship hulls were magically engineered by Elves and provided their own stable, life-supporting environments and solve the cooling problem pretty much automatically: The leaves at the rear along with the internal circulation system act as a giant waste heat array (sidenote: the hulls would need to be a pored or fibrous wood like a hardwood or palm. Yes I was REALLY into shop class in Highschool). Internally they also recycle CO2 into O2. win/win.

Pretty much everything else has to be added on once a ship is mature enough to be usable (i.e. fit at least four people in relative comfort): 50 or so years.

The engines were just force spells which provide a pushing force against the rear of the craft also providing the Waste Heat Array with a limited protection from weapons fire.

Attitude control was entirely mechanical. High-quality rope (think steel cable) on a block and tackle arrangement to reduce force required to operate it. Making the best place for the bridge/conn to be near the engines on the centreline of the ship (FINALLY! A tactically significant location on a space vessel that is PROPERLY situated!).

You could also go with a DnD analogue for a solar sail to give things a little more high-seas feel. Just feel free to ignore the massive sail-area to weight ratio unless you like the idea of a 30-person vessel having a sail area of a large city. Not too sure on what to use for an analogue... maybe a material that has a higher concentration of positive energy than normal, and thus in strong light the two act like matching poles between two magnets.

For fast travel, maybe consider a number of transitive planes to which portals can be opened (or found?) and each one has a different speed ratio to normal space (much like hyperspace (http://en.wikipedia.org/wiki/Hyperspace_(science_fiction)#Babylon_5))

Weapons:
Spells would be an obvious choice. But not all of them. Fireball, chain-lightning etc would still require oxygen to work (but them I'm the sort of DM who LIKES the idea of titanium elementals). In addition to that being a vacuum the percussive force of an explosion is going to be limited to direct contact with an enemy vessel and heat energy will disperse much quicker.

Meteor-swarm is always win

As always your best-bet is a kinetic weapon. But, despair not! Just like you can have shock/fire/frost arrows arrows, why not have shock/fire/frost torpedoes? bullets of shaped stone wrapped in bands of steel/adamantium and enchanted with maximised fireball, that, once the prow of the missile strikes the hull of a target it activates the spell blowing away pieces of hull in a manner much like an AP shell. YAY!

As always though: Keep it fantasy. Fantasy in space is always a fine line to walk, dealing with real-world physics vis-a-vis space in a fantasy setting kills the fantasy aspect of it, and solving said problems with magic kills the sci-fi aspect of it. This is what killed my enthusiasm for my own project in the end. Best advice: if it looks cool and makes the setting come alive: it's in. If it destroys suspension of disbelief: it's out. So maybe go the whole Treasure Planet (http://www.youtube.com/watch?v=AMGXq9_IQBQ&feature=related) route and hang everything else.

Edit: The spaceport in that movie was EXACTLY the way I always imagined Sigil to look.

archon_huskie
2009-05-25, 09:05 AM
Know direction is no good. It tells you what direction is north. There is no North in space.

Not technically true. There is a Galatic North pole with regard to the central mass of the galaxy and the direction of which the galaxy spins around the central mass However, simply knowing Galatic North is not going to help in navigating a three dimensional area.

You will need to know the distance you are from the Galatic North pole, the distance you are from the Galatic South pole, and the distance from two other known points in the galaxy to determine your location in the galaxy.

Truthfully the discance from any four known points will work. That's how Satellite tracking works. But since we want to travel around the galaxy let's modify the Know direction spell to allow us to determine the distance to North and another Know direction spell to determine the distance to Galatic South. Next you will want to modify the Locate object spell so that you will know the distance from a particular object. Once such object will be placed here on Earth.

Your ship's first misson should be to place the second Locate Object a good distance away from Earth.

Radar
2009-05-25, 09:40 AM
No space is not cold. There's nothing out there to be cold. Radiation is a lot less efficient than conduction, so the heat loss will be minimal for something with such a tiny surface area.

Planets dissipate heat well because they are ****ing massive and also because they only actually receive any energy on one half at a time.
1. There is cosmic backgroung radiation - remnant of a Big Bang (as in our universe) or just radiation from distant stars and other objects. It does have a temperature as weird as it sounds and can be important when calculating thermodynamical balance.
If there is totally nothing, temperature is 0K (that's zero, not O - for clarity).
2. With temperature of 300K, an ideal black body would radiate 460W per m^2. Assuming a cube 10X10X10m (a small spaceship) and emissivity of 0.3 (good estimation for a metal) we will get 138kW of energy loss due to radiation. Heat capacity of iron is 3.5MJ/(Km^3). Even if the whole cube is iron, it's temperature will fall by 1K every 7 hours - a lot faster considering, that most of the volume will be taken by air. It's neglectable, if the space travel is short, but for a longer ride it has to be dealt with by adding a heat source.
3. Actually the smaller the object is, the faster it looses thermal energy - surface grows with the size^2, heat capacity grows with size^3. It's not imoprtant for the Earth, since it's more or less in balance.
4. Yes, Earth doesn't heat up too much, because only one half is exposed to Sun radiation, the other is exposed only to background radioation which is a lot weaker. If Earth maintains thermal balance, while being constantly charged by Sun, then a spaceship that is not exposed to external/internal light/heat source will gradually get colder.

charl
2009-05-25, 10:28 AM
All you need is a spellhelm and enough rations and water to last for the journey.

Radar
2009-05-25, 10:42 AM
All you need is a spellhelm and enough rations and water to last for the journey.
Traps of Creat Food/Water. Traps of Prestidigitation to flavor the food and for cleaning purpose.

That is, if you don't bother to cast those spells yourself.

Jayabalard
2009-05-25, 11:09 AM
something to survive spaces cold climate.Space isn't cold; since vacuum (or near vacuum) is a such a good insulator, the problem tends to be that you can't lose heat fast enough.


Even if the whole cube is iron, it's temperature will fall by 1K every 7 hours - a lot faster considering, that most of the volume will be taken by air. That's not a good example; you're ignoring the most important fact: any occupied vessel contains life forms, which produce heat as one of their waste products; they're probably going to have some sort of light, which also adds heat; if the vessel is technology based then they probably have other machinery, which gives off more heat as waste.

Going back to what spurred the origional point: "Space's cold climate" ... the radiative heat loss that you mention is nothing compared to the heat loss due to convection in a cold earth climate... I seriously doubt that it's even comparable to the convective heat loss in most hot earth climates.

Radar
2009-05-25, 11:25 AM
Space isn't cold; since vacuum (or near vacuum) is a such a good insulator, the problem tends to be that you can't lose heat fast enough.
It might be true for an astronaut in a spacesuit, because a human body generates a considerable ammount of heat. It's quite the opposite for a spaceship that doesn't have any significant heat source.
edit:

That's not a good example; you're ignoring the most important fact, which is that any occupied vessel contains life forms, which produce heat. Quite a bit of heat.
Yes, about 100W per person of heat radiated (that's recalculated to about 2000 kcal per 24h - we eat about that much a day) - compare that to 138kW, which the ship radiates. You will not comfortably fill the 10X10X10m space with 138 humans to compensate that. With bigger ships things will start to change (volume increases faster then surface), but we are talking really, really big spaceships then.

Jayabalard
2009-05-25, 11:33 AM
It might be true for an astronaut in a spacesuit, because a human body generates a considerable ammount of heat. It's quite the opposite for a spaceship that doesn't have any significant heat source. See my post above (http://www.giantitp.com/forums/showpost.php?p=6151652&postcount=24).You happend to catch me while I was editing in a response to that... your example is not useful. Ships generally have people in them too; humans, light sources and machinery all add up to a fairly significant heat source.

Radar
2009-05-25, 11:57 AM
You happend to catch me while I was editing in a response to that... your example is not useful. Ships generally have people in them too; humans, light sources and machinery all add up to a fairly significant heat source.
People and other normal living creatures have been adressed already (this time you catched me, while i edited to include your edit :smallsmile:). As for machinery: there isn't any - there is just hull, Decanters of Endless Water (they might heat up in geyser mode, but i don't have info on that) and some magical devices - not much to go about.

RL examples: ISS - it is kept in thermal balance for obvious reasons and it's heated by the Sun; it also has more heat generating objects, then a magical spaceship would have. So far away from stars with less heat sources the outcome is obvious. Also the Apollo 13 astronauts had low temperature problems, when they shut all systems down to conserve energy.

charl
2009-05-25, 01:44 PM
The Phlogiston conducts heat very well. It is in fact flammable, so over-heating is not going to be a problem, unless you plan on lighting huge bonfires on deck, but even then your ship will be enveloped in a cloud of air that lasts for several months and as such must be pretty large.

Jayngfet
2009-05-25, 01:49 PM
Prestidigitation can, in addition to adding flavor, cool the ship off slightly. Ray of frost, another cantrip, can be cast as well.