Making ANY Scifi Spacecraft Hull Work

[Spacescifi]

 

I used to think that certain shapes are not to be used for spaceships at all, but tje truth is that with a little tinkering any and all shapes are viable for manned scifi spaceflight. Tinkering with the hull shape and deck layout only that is.

For example, in scifi most spaceships have engines at the rear, not the bottom, which would make all fall backwards under acceleration.

Solution? Put rotatable cylinders inside the hull and rotate them so that their floors are oriented 'down' with the acceleration.

Why do this instead of simply building the ship like skyscraper with thrust oriented beneath?

Cargo loading. Easier to do the closer a vessel's decks are to the ground. Having your main engines between you and the ground can make it more complex.

 

Angular or square hulls: While it is still true that pressurizing sharp angles is a bad idea, there is a way to still have them.

How?

 

Imagine the square is the outer hull. Thick I know! The inner hull is curved though, and flat decks can be put accross it as desired. Thus the internal air pressure won't hurt the angular outer hull at all.

Angular hulls seem to imply thick hulls, since there is no sane reason to pressurize them.

 

That's my two two cents on the matter, you may add to this or point out something I have not already.

Edited January 5, 2020 by Spacescifi

[razark]

4 hours ago, Spacescifi said:

The inner hull is curved though, and flat decks can be put accross it as desired. Thus the internal air pressure won't hurt the angular outer hull at all.

Why not do it the way submarines do? An round inner pressure hull, surrounded by an unpressurized outer structure of whatever shape you wish?

[Spacescifi]

9 hours ago, razark said:

Why not do it the way submarines do? An round inner pressure hull, surrounded by an unpressurized outer structure of whatever shape you wish?

 

Is that not what I said?

 

Same concept really. Even the picture I provided.

The only downside is extra hull weight from being thick, but a legitimate scifi ship needs that

[razark]

1 minute ago, Spacescifi said:

Is that not what I said?

It might be.  I think my mind took it as meaning something else.

However, if it is, then I don't understand the "Angular hulls seem to imply thick hulls..." part, and I took the picture to be an open inner area, surrounded by a square hull structure with very thick corners?

And "The only downside is extra hull weight from being thick..." makes me wonder.

 

What I'm talking about is shown in the cross sections on the right.  The inner circular section is the pressure hull, and contains all the people and equipment that need to be kept dry.  Everything outside that is open to the sea, and the outer hull is simply for streamlining.  In the case of a spaceship, you would have a similar setup, with the people-tank surrounded by whatever shape outer hull you want, of any thickness.  In addition, this outer hull could serve a spaceship as a Whipple shield to protect from debris impacts.

Is this what you were referring to?

[Gargamel]

1 hour ago, Spacescifi said:

The only downside is extra hull weight from being thick, but a legitimate scifi ship needs that

Why would a spaceship require a thick hull?   It only has to hold in a single atmosphere, or even a fraction of that...  A spacecraft might require shielding, and that might be thick, but shielding =/= hull. 

The reason subs have double hulls is that they require a place to store things that they want inside the vessel, but are not needed inside the crew areas, like ballast tanks and batteries. 

[kerbiloid]

25 minutes ago, Gargamel said:

Why would a spaceship require a thick hull?

To survive and win!

Spoiler

 

Especially from ~01:00, the protagonists' ship looking exactly like a space submarine.
Neil Johnson rulez! _{(It's a part of his space saga.)}

Edited January 6, 2020 by kerbiloid

[Spacescifi]

On 1/5/2020 at 10:16 PM, kerbiloid said:

To survive and win!

  Hide contents

 

Especially from ~01:00, the protagonists' ship looking exactly like a space submarine.
Neil Johnson rulez! _{(It's a part of his space saga.)}

 

Wow. That is a B movie if I ever saw one.

It says that guy is the last human but I saw nothing but humans in the trailer who appeared to be the bad guys.

 

Oh well... I guess the actors did'nt wanna wear colored makeup and go the rubber forehead route like Trek does.

 

Edited January 7, 2020 by Spacescifi

[kerbiloid]

1 minute ago, Spacescifi said:

It says that guy is the last human but I saw nothing but humans in the trailer who appeared to be the bad guys.

He is the only natural human there.

Oops, no, not in that sense...

Just others are augmented ones, konstructs, robots, upgraded races, etc.

Edited January 7, 2020 by kerbiloid

[Fraktal]

On 1/6/2020 at 6:51 AM, Gargamel said:

Why would a spaceship require a thick hull?

Protection during aerobraking.

Same reason why @razark's idea is sound in vacuum due to saving weight, but leaving holes/seams in the outer hull is asking for a Columbia if the ship is meant to enter atmosphere at any point.

[magnemoe]

On 1/5/2020 at 7:48 PM, razark said:

Why not do it the way submarines do? An round inner pressure hull, surrounded by an unpressurized outer structure of whatever shape you wish?

Except submarines has to handle 20-50 bar outside pressure, spaceship only need to handle 1 bar internal. You don't need to make round structures for 1 bar pressure, you want rounded corners and round is lighter and strong so nice for structures. 
Rockets are also round. 

Now you need insulation outside the habitation and also part of the equipment like much of the storage, life support  and equipment. 
If you enter an atmosphere you will need an aerodynamic hull with heat shielding, think the shuttle or starship. If you only aerobrake this can just be the front or one side. 

Lots of scifi starship like in star wars and star trek has an ship deck layout because the designers are lazy and have no clue, yes the shuttle is also set up this way. however its in zero g outside of launch and landing. 
The spaceship in Freefall is also set up this way.

however its used either for an landed base and it lands flat like the shuttle, takeoff and landing, in zero g, or an multi day 0.1 g trust there they just live with the ship being unpractical for some days. The table can be rotated. assume beds is also set up to be moved. 

Starship uses an tower design who would be preferred for an tail lander. This is also the floor design you would use on an warship or other ships who has to trust hard and long. 

You can have crew modules who can be both spin and rotated so they always has an 1 g downward however I think having one trust and one spin living area will be easier assuming you trust 0.5-1 g for 2-20 months and then cruise for an longer time before braking, the trust compartments can still be uses in 0 g during cruise. However if the crew compartment is very small compared to the ship and the trust phase is long the folding and rotating crew quarter might win out. 
 

[Spacescifi]

38 minutes ago, magnemoe said:

Except submarines has to handle 20-50 bar outside pressure, spaceship only need to handle 1 bar internal. You don't need to make round structures for 1 bar pressure, you want rounded corners and round is lighter and strong so nice for structures. 
Rockets are also round. 

Now you need insulation outside the habitation and also part of the equipment like much of the storage, life support  and equipment. 
If you enter an atmosphere you will need an aerodynamic hull with heat shielding, think the shuttle or starship. If you only aerobrake this can just be the front or one side. 

Lots of scifi starship like in star wars and star trek has an ship deck layout because the designers are lazy and have no clue, yes the shuttle is also set up this way. however its in zero g outside of launch and landing. 
The spaceship in Freefall is also set up this way.

however its used either for an landed base and it lands flat like the shuttle, takeoff and landing, in zero g, or an multi day 0.1 g trust there they just live with the ship being unpractical for some days. The table can be rotated. assume beds is also set up to be moved. 

Starship uses an tower design who would be preferred for an tail lander. This is also the floor design you would use on an warship or other ships who has to trust hard and long. 

You can have crew modules who can be both spin and rotated so they always has an 1 g downward however I think having one trust and one spin living area will be easier assuming you trust 0.5-1 g for 2-20 months and then cruise for an longer time before braking, the trust compartments can still be uses in 0 g during cruise. However if the crew compartment is very small compared to the ship and the trust phase is long the folding and rotating crew quarter might win out. 
 

 

Yeah it depends on whether you have a jump drive and sufficient constant thrust or not.

1g for correcting orbital speed differences can take less than hour or several hours to days or more. Just depends on how vast the speed distances are relative to where you started.

[Gargamel]

17 hours ago, Fraktal said:

Protection during aerobraking.

Same reason why @razark's idea is sound in vacuum due to saving weight, but leaving holes/seams in the outer hull is asking for a Columbia if the ship is meant to enter atmosphere at any point.

Again, shielding =/= Hull.   The was a hole in columbia's shielding, not it's hull.   That's why it failed.  

Thick hull = more mass = less dv available to you.   Thin hull with appropriate lightweight shielding = less mass.

[kerbiloid]

Just to be said.

The enormous pressure at the Venus surface is 90 atm ~= 1 km of the Earth ocean.
The already visited Mariana Trench is 11 km deep ~= 12 times greater than on Venus. Just cooler.

So, there should be strength classes of the future spaceship space hulls:

0 = 1 m depth = 1 atm = no strength, just an envelope, or unpressurized hull
1 = 10 m depth = 2 atm (depth + air). For the Earth splashdown, for Venusian cloud stations, for Titan.
2 = 1000 m depth = 100 atm.  For the Venusian surface or for coastal areas of the Earth.
3 = 10000 depth m = 1000 atm. The deepest possible depth in the Solar Sysem except the gas giants.
3+ or 4 = 20000 m depth. At this depth the capsule would be almost a solid metal ball with no room inside. Just4lulz.

N.B.
Jules Verne's Nautilus has visited 16 km depth, iirc. 3+.

Edited January 8, 2020 by kerbiloid

[magnemoe]

5 minutes ago, kerbiloid said:

Just to be said.

The enormous pressure at the Venus surface is 90 atm ~= 1 km of the Earth ocean.
The already visited Mariana Trench is 11 km deep ~= 12 times greater than on Venus. Just cooler.

So, there should be strength classes of the future spaceship space hulls:

0 = 1 m depth = 1 atm = no strength, just an envelope, or unpressurized hull
1 = 10 m depth = 2 atm (depth + air). For the Earth splashdown, for Venusian cloud stations, for Titan.
2 = 1000 m depth = 100 atm.  For the Venusian surface or for coastal areas of the Earth.
3 = 10000 depth m = 1000 atm. The deepest possible depth in the Solar Sysem except the gas giants.
3+ or 4 = 20000 m depth. At this depth the capsule would be almost a solid metal ball with no room inside. Just4lulz.

N.B.
Jules Verne's Nautilus has visited 16 km depth, iirc. 3+.

Its not like that you will land an spaceship on Venus anyway. 
Think we can classify ships into either landers or ships who stay in space, and then if you land in atmosphere as in Earth, mars or Titan. or land on air less bodies like the Moon and other bodies with relevant gravity. 

Yes some ships like starship or the savage chicken in Freefall can can do both but this has its downside like no spin gravity, it let you aerobrake but only at pretty low speeds, not at the end of an week with an 1 g acceleration  If you land in atmosphere you need aerodynamic and heat resistance. 
For landing on the Moon you need landing legs and an strong enough engine to slow down.  You want to use the lander to be used after landed you want the floor to be down

However an in space only ship let you use spin gravity and also engines you can not put inside an hull like nuclear engine, it also let you use huge radiators or solar panels. 
Her you don't really need an external hull however it can be practical for one it protect from micro meteorites and debris, especially if spaced out a bit from the insulation below. 
Also easier to see if something hits and make the ship looks better. Same goes for actual armor but here you want more layers and more distances. 
 

[Nuke]

i like the idea of surrounding the crew area with your mission consumables. things like water, spare parts, fuel, etc. you have to carry it anyway so why not use it as radiation shielding. then you have whatever superstructure you need to support the drive, reactor, radiators, solar, etc built on top of that. i even thought about making the whole kitten kaboodle a toroid so you could spin for gravity, but that might be problematic structurally. endo spin or thrust gravity might work better in this config. 

19 hours ago, magnemoe said:

Except submarines has to handle 20-50 bar outside pressure, spaceship only need to handle 1 bar internal. You don't need to make round structures for 1 bar pressure, you want rounded corners and round is lighter and strong so nice for structures. 
Rockets are also round. 

Now you need insulation outside the habitation and also part of the equipment like much of the storage, life support  and equipment. 
If you enter an atmosphere you will need an aerodynamic hull with heat shielding, think the shuttle or starship. If you only aerobrake this can just be the front or one side. 

Lots of scifi starship like in star wars and star trek has an ship deck layout because the designers are lazy and have no clue, yes the shuttle is also set up this way. however its in zero g outside of launch and landing. 
The spaceship in Freefall is also set up this way.

however its used either for an landed base and it lands flat like the shuttle, takeoff and landing, in zero g, or an multi day 0.1 g trust there they just live with the ship being unpractical for some days. The table can be rotated. assume beds is also set up to be moved. 

Starship uses an tower design who would be preferred for an tail lander. This is also the floor design you would use on an warship or other ships who has to trust hard and long. 

You can have crew modules who can be both spin and rotated so they always has an 1 g downward however I think having one trust and one spin living area will be easier assuming you trust 0.5-1 g for 2-20 months and then cruise for an longer time before braking, the trust compartments can still be uses in 0 g during cruise. However if the crew compartment is very small compared to the ship and the trust phase is long the folding and rotating crew quarter might win out. 
 

deck style layouts are only acceptable for belly landers, the shuttle falls into this category. for when it spends any amount of time flying in an atmosphere (not falling). like in expanse season 4, un1 gets away with it because they actually show the ship disembarking from another vessel. i presume you could argue that the ship is stowed for transit on a more conventional thrust gravity configuration (may even be docked cross axially such that mothership down == belly lander down, or the crew may move to the mothership for transit). once docked it is essentially cargo. incidentally in the books the rossi is actually capable of belly landing. but i think they didnt want to confuse people who may already be confused. 

Edited January 8, 2020 by Nuke

[magnemoe]

3 hours ago, Nuke said:

i like the idea of surrounding the crew area with your mission consumables. things like water, spare parts, fuel, etc. you have to carry it anyway so why not use it as radiation shielding. then you have whatever superstructure you need to support the drive, reactor, radiators, solar, etc built on top of that. i even thought about making the whole kitten kaboodle a toroid so you could spin for gravity, but that might be problematic structurally. endo spin or thrust gravity might work better in this config. 

deck style layouts are only acceptable for belly landers, the shuttle falls into this category. for when it spends any amount of time flying in an atmosphere (not falling). like in expanse season 4, un1 gets away with it because they actually show the ship disembarking from another vessel. i presume you could argue that the ship is stowed for transit on a more conventional thrust gravity configuration (may even be docked cross axially such that mothership down == belly lander down, or the crew may move to the mothership for transit). once docked it is essentially cargo. incidentally in the books the rossi is actually capable of belly landing. but i think they didnt want to confuse people who may already be confused. 

If you have an long ship you could do an tumbling pigeon, yes this would make the floor towards the front of the ship. 
And yes you could have an stove position there down is towards the engines. However if the shuttle is mostly an low orbit-ground- low orbit use and then docked to an interplanetary ship it would be cargo anyway. If its has crew living space this could be used 
But if you do tumbling pigeon make bottom of shuttle up

The savage chicken in freefall could have avoided the long term low powered trust from back if they had the high ISP low trust engines on the bottom, it has vtol engines here anyway. 
It has some very efficient polywell style fusion reactors however one reactor is an box in the cargo hold, if you go past low orbit you are required to have two fusion reactors.  Its said the low trust engines is some sort of ion engines ship also has an higher trust lower ISP engine in the back to get into orbit, if fueled for orbital burn it need an linear accelerator to get it supersonic. 
Recommend the freefall comic, its very hard scifi outside of some rules of funny and some minor mistakes, I don't think an skyhook would be very relevant if you have 95% efficient fusion. and get an extra reaction mass tank in orbit for one. 

Has to get the expanse. 

[Nuke]

you could probably turn a shuttle into a centrifuge if you instal a counterweight and tether system in the cargo bay. deploy for spin. tether could also double for power generation. for a space plane going say from earth to venus it makes sense to be a belly lander since you are going to need one at both ends. once you get into space it doesn't matter how you orient the craft. you could have your transfer engines pointing down through some doors in the heat shield so the belly down orientation still works (either in a constant thrust or tumbling pigeon).

Edited January 9, 2020 by Nuke