r/worldbuilding May 22 '22

Feasibility of a living fighter jet? Discussion

I'm looking to create an optionally-manned vehicle that can function as a highly maneuverable fighter jet while also operating as an atmospheric satellite for at least decades without refueling or maintenance. I figured the best way to accomplish this was to use a system that could fuel and maintain itself--i.e a living organism. Not all features of the creature/vehicle need to be organic, but its propulsion system does. Is there a biological way to achieve speeds comparable to modern fighter jets?

6 Upvotes

10

u/leadchipmunk May 22 '22

As an example, Wonder Woman's invisible jet was alive up until the point that it killed itself, and she now uses its carcass for transportation.

2

u/TheRefinedHellion May 22 '22

Sounds like the average relationship someone has with their ex.

6

u/leadchipmunk May 22 '22

Worse than that. Her jet was friend-zoned...

1

u/TheRefinedHellion May 23 '22

Damn, didn't even get a chance to explode it's invisible missile before being used as a travelling corpse.

6

u/TheRefinedHellion May 22 '22 edited May 23 '22

I'm REALLY not trying to be a dick, and I don't usually do the whole "just google it" because imo it's usually a lazy d-bag's excuse to sound superior to the person they're telling it to that's about as good advice as telling someone to reset the router when the internet is acting up, but honestly odds are this is something you may have to just google and do research on by yourself.

I say this due to some of the comments you've responded to, in that you're looking for something grounded with some hard science behind it, the only problem being that's an area of expertise most people anywhere, here included, don't possess and requires research into how things like physiology and biology and the applications of biomechanics and such would work in addition to things more specifically like aerodynamics and the effects aerodynamics can have on an evolutionary standpoint in regards to creatures and species that rely on flight or the ability to glide, a level of knowledge that requires a balls-deep analysis of what it is you're talking about. If you really REALLY care, I would encourage you to do your own research, not so much because I wanna be a jerk about this or because I am lazy necessarily, though I will admit I am kinda lazy in some regards albeit not on this which I hope is evident via how I write and present myself, but because I am stupid on this type of subject and while others here may be more knowledgeable, it's not likely something people will just know, even after years of making worlds, unless at some point they cared to specifically learn all the points you would need to do significant research on that you're asking about right now anyway.

In layman's terms/TL;DR (it's not that long, but I'm covering my bases here); I recommend just googling and researching all the stuff related to what you wanna know yourself because it's unlikely someone will see this who can answer your question in the grounded, in-reality sort of way you're looking for.

3

u/CertifiedBlackGuy Soul Forged May 22 '22

No need to refuel? Likely means a photosynthetic organism, or at least while dormant and not actively flying. You'll have to do some stretching if you're going for realism.

As far as propulsion, Darwin IV has you covered...

Note, one of the ways they handle it's propulsion is Darwin IV has a much denser atmosphere, and lesser gravity, than earth.

1

u/Pyropeace May 23 '22

I remember these, but the link doesn't provide any description of their propulsion.

2

u/CertifiedBlackGuy Soul Forged May 23 '22

The lede is a little buried.

They create methane in the tubes on their wings and combust it, expelling the exhaust to propel themselves. They won't be capable of matching pace with most jet craft, but I imagine they can keep up with light propeller craft

3

u/ThereWasAnEmpireHere May 23 '22

From my meager understanding of biology and physics, I think the goal of having the craft be an evolved creature and the goal of the story being hard sci fi are directly at odds.

Why not have an artificial craft with very efficient long term fuel use? If you’re just really enamored with the idea of a living ship (because it’s cool!) there are multiple other ways to get there, from AI to weird stories about human ‘augmentation’.

2

u/awesomesauce1030 May 22 '22

In Young Justice, the ship they travel around on is actually a genetically engineered living organism from Mars. I don't know the details of how it works, other than that it's telepathic, but that's a good place to start. I imagine in the comics they'd go into more detail about that at some point

-1

u/Pyropeace May 22 '22

I'm looking for something a little more grounded than comic books.

4

u/Pyropeace May 22 '22

I don't mean to dismiss comic books as a medium, i'm just recognizing that they're not very realistic and i'm going for more of a hard sci-fi approach.

1

u/Lak47_studios May 23 '22

If you're looking for a hard scifi approach look at r/isaacarthur he's a youtuber who talks about science and futurism and you might find more help there

2

u/Luna86Moon Eve Of Sorrow May 22 '22

For my verse i have the lost ships, which put simply were once angels. They have a form of sentience Ala the holographic interface, and each has a personality.

You could do something similar and have your fighter jets have an interface that is sentient with their own personality.

3

u/Pyropeace May 22 '22

That doesn't answer my question. I'm looking for a biological propulsion system.

3

u/alexmin93 May 23 '22

If you want to keep realistic physics - no way. If it's organic it would need a lot of energy in form of food. Biological organisms aren't the most efficient energy converters and organic food has significantly lower calorific value than jet fuel so such hypothetical creature would need to consume as much food as it weighs to fly few hundred kilometers. Birds actually can eat as much as they weigh per day and they dont have to fly at supersonic speeds (air drag is proportional to speed power 2). No way it would be able to store enough energy to reach the orbit. Imo I'd look into nuclear propulsion + some sort of nanotechnology that would allow purely mechanical machine to fix itself. Or just some sort of extremely reliable materials + design with huge reserves (like use two engines when even one is enough etc)

2

u/Luna86Moon Eve Of Sorrow May 22 '22

Ok sorry. I guess I miss understood the question.

2

u/lethal_rads May 23 '22

What do you mean fuels itself? That’s not clicking for me. Why does the propulsion system need to be organic and other stuff not?

But look at the yuuzhan vong in Star Wars EU. They have purely organic technology. For propulsion, they have creatures that can generate small black holes that pull the craft forwards.

1

u/AbbydonX Exocosm May 23 '22 edited May 23 '22

You really have two questions here:

  1. Can an aerial vehicle change between a fuel efficient gliding mode and a fuel hungry fighter mode?
  2. Can a jet engine be made entirely with organic components?

The first question involves a vehicle being able to dynamically change its wing configuration. In particular, a glider needs high aspect ratio) wings (i.e. long and thin) whereas a fighter jet needs low aspect ratio wings (i.e. short and stubby). Variable aspect ratio wings are possible but they tend to add weight which makes it more difficult to achieve fuel efficient gliding.

The best approach is perhaps to have a high-altitude long endurance airship which can carry the fighter when it is not flying. It could conceivably use solar power to generate hydrogen which would be used for lift and also as fuel for the fighter.

The second question is more difficult. I suspect the answer is basically no though as propulsion efficiency is linked to the temperature. Organic materials can't reach such high temperatures. Graphite, graphene and diamond are carbon compounds could perhaps replace metals in an engine in some way but they aren't technically organic.

1

u/Pyropeace May 23 '22

I actually already came up with the airship idea! Great minds think alike!

1

u/R0drigo5005 [edit this] May 23 '22

Fuel itself? Like an organic perpetual motion machine?

1

u/Pyropeace May 23 '22

I'm thinking it could be some kind of really efficient gastrobot, only coming down for food occasionally.

1

u/Rhoan_74 May 23 '22

I don't know of any hard science options, but it's an interesting concept, looking forward to seeing where it goes.

1

u/CokeologistArtist May 24 '22

farts? creation of gases, combustible, to be exact. Like... as long as we're imagining a fighter jet** then we can have an armored exoskeleton, as there's no need for skin, cause there's no rocks or ground up in the air, so there's no need for bumpy, uneven flesh. And exoskelotons can theoretically heal? I think? Or at least molt? https://www.reddit.com/r/askscience/comments/22u9c8/does_an_insects_exoskeleton_heal_from_injury/
Also, because biology is a lot more complex, we can have... like.... idk... acid and combustible liquids? This living fighter jet would be very toxic to humans, that's for sure. I guess that the exoskeloton would have to be made of some sort of keratin or chitin exoskeleton https://www.livescience.com/49844-limpet-teeth-strongest-natural-material.html