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Project Hyperion: Interstellar ship design competition

projecthyperion.org

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Re: Project Hyperion: Interstellar ship design competition

#321

Post by vl »

nn3 wrote: post #107
vl wrote: post #102

Earlier quoted context omitted.

Cool concept, but some things are just strange: Power provided by toroidal nuclear fusion reactors in the outer shell of the living module, but why do you need such reactors if your primary propulsion is provided by Helium 3 - Deuterium Direct Fusion Drive? If you have direct fusion technology, you don't need toroidal reactors. Rotating inner shells mechanically for 400 years is terrible design, it's much easier just…

If you would spin the whole structure you couldn't have multiple shells all with 1G on their surface. The required spin speed for 1G depends on the diameter. But their whole concept is built around multiple shells, which is clear from the name. Regarding the GDP needed once you have a working "mine from the moon and send to orbit" economy it doesn't seem to be too bad. The assumption would be that a lot of technology…

Re: orbital assembly. L1 point is bad in every respect. If most materials come from Moon, then the best assembly point is low Moon orbit (as benefit you get a boot to your launch speed to escape Earth gravity), if most material comes from Earth, then best assembly point is low Earth orbit. Hauling all material to L1 is going to be more expensive in either case (unless the ratio of materials is very exact, which is unlikely).

Re: spin. I still claim that the best design is to rotate entire living module as one. Most of the activity is going to be on the outer shell. Warehouses, etc will be in the lower gravity inside. No moving parts.

The only question is what to do with fuel and retro engines. Rotate them as well? Fuel tanks need to be stronger. Do not rotate? Then maybe living module can undock for the flight and rotate separately.

Re: Project Hyperion: Interstellar ship design competition

#322

Post by vl »

JumpCrisscross wrote: post #44
BizarroLand wrote: post #38

Earlier quoted context omitted.

The question is how well will they hold up for 400 years? Well, that, and how do you ensure that the people 400 years from now would know what they are for or how to implant them? Lots of unknowns. Would make for an interesting story though

> how do you ensure that the people 400 years from now would know what they are for or how to implant them? A ship travelling at 0.01c for 400 years could get 4 ly away. They'd still be able to be coached. More likely: their computers would still be able to be updated.

Of course there is this thing is that while they were coasting faster technology was developed and another ship arrived way before them, with better computers, engines, everything.

Re: Project Hyperion: Interstellar ship design competition

#323

Post by protocolture »

jmyeet wrote: post #110
protocolture wrote: post #93

Earlier quoted context omitted.

The winning design assumes redundant toroidal fusion reactors.

Having a fusion engine or fusion reactor is basically hand-waving away the energy problem. Controlled fusion has a fundamental problem: neutrons. Even if you solve the problem of container destruction (ie neutron embrittlement), which is significant, you still face the problem of significant energy loss to the system through high-energy free neutrons. Stars solve this problem by simply being really large so a free ne…

IIRC (Its a long document, and I only skimmed it) they assumed 20% efficiency on behalf of the reactors.

I think they just wanted a plausible future energy source that they didnt have to look at too closely.

My first issue with the design is that it looked like a decent percentage of the planet would have to be launched into space just to build the thing.

A lot of the space math looked alright, but theres several issues of practicality.

>Even if you solve the problem of container destruction

No idea if this is related, but everywhere they needed 1 reactor, they had 4. 2 in active/active failover, and 2 cold spares. It seemed relatively easy for them to perform maintenance on these. But its just heaps more launch mass, heaps more acceleration fuel, and a lot more deceleration fuel.

Re: Project Hyperion: Interstellar ship design competition

#324

Post by AtlasBarfed »

vl wrote: post #317
WithinReason wrote: post #181

Earlier quoted context omitted.

But then the whole project takes thousands instead of hundreds of years

And also it requires extraordinary navigation precision. These launches are going to be spread in time, which means that they don't happen from the same place (all celestial bodies move relative to each other). Which in turn means that when you approach the pellet there is going to be perpendicular velocity component. Even without taking this into account all systems are going to need active guidance - there is no wa…

I didn't say it would be easy :-)

But orion pulse nuclear propulsion is pretty powerful stuff, especially if you can antimatter-catalyze it.

Re: Project Hyperion: Interstellar ship design competition

#325

Post by thmsths »

vl wrote: post #318
thmsths wrote: post #307

Earlier quoted context omitted.

Your washing machine probably used cheap nylon gears which self destructed. There are windmills older than 400 years old that still operate today despite using gears :)

This is false example - these windmills are actively maintained and repaired, how are you going to replace massive gears or bearings in space? Are you going to bring spare parts with you?

No, you will bring manufacturing capabilities with you. Decently sized warships carry a machine shop for a reason. A generation ship will have to be totally self sufficient, this will include not just food, air and water but also being able to manufacture pretty much anything they might need.

Re: Project Hyperion: Interstellar ship design competition

#326

Post by throwaway290 »

random_is_rando wrote: post #245
throwaway290 wrote: post #243

Earlier quoted context omitted.

Measuring spin is impossible without changing the particle. You assume a human is the same as a chair? seems like a stretch

I don't understand, what is the purpose of measuring electron spin for your various atoms? Electrons are in a probability cloud, you need to scan/replicate the atomic structure, not measure the electron spin of your atoms. Doesn't really make sense for me, do you have something particular in mind or?

> Doesn't really make sense for me, do you have something particular in mind or?

Do you? I already said what I have in mind. particles are not indistinguishable and "scanning" objects without destroying them not possible in this reality

Re: Project Hyperion: Interstellar ship design competition

#327

Post by kanisae »

m4rtink wrote: post #296
antisthenes wrote: post #278

Earlier quoted context omitted.

It's not going to work because the energy requirements of reaching another habitable planet through interstellar space are mind-bogglingly high. You need to be able to run a fusion reaction in space, for 100+ years and have absolutely nothing in the system break or require maintenance. Until you do this, these spaceship competitions are just fancy CGI renders.

I think with highly enriched uranium you could definitely power a (set of spare) fishion reactors for that long during transit with reasonable mass budget.

Fission is the way to go for this for its general simplicity of design and it can self start by manually moving control rods. I never see anyone talking about they are going to restart a fusion reactor if it ever goes offline for any reason.

My thought is to use fission for powering the ship, and fusion for the drive. The fission reactors can start the fusion drive as needed and you can have multiple portable fission reactors like the NASA kilopower designs in an offline/inert state that could be powered on in an emergency.

Re: Project Hyperion: Interstellar ship design competition

#328

Post by xyzsparetimexyz »

protocolture wrote: post #89
Paul_S wrote: post #18

I love that most of those designs give bigger houses to people in a spaceship than modern houses in the UK on planet earth. Love the designs, doubt democracy would get them through more than 250 days, let alone 250 years.

Hypothetically, if you designed something that resembled the UK and tried to have humans live in it, that would not be ethical.

Yankee go away

Re: Project Hyperion: Interstellar ship design competition

#330

Post by gaws »

munificent wrote: post #100
JumpCrisscross wrote: post #29

Earlier quoted context omitted.

> we are never leaving this solar system unless we discover some new physics to get around our speed limitations The winning proposal coasts at 0.01c. Propulsion systems--not the speed of light--and thus engineering, not phsyics, are the relevant limitors.

I am increasingly certain that culture is by far the biggest limiting factor when it comes to large-scale problem solving now and in the future. We couldn't even reliably get people to put a piece of fabric over their face to stop killing their own relatives. Even if we could build a generation ship, it would turn into an Event Horizon hellscape if we don't figure out better cultural, communication, and sociological…

> I am increasingly certain that culture is by far the biggest limiting factor

We're never leaving because "woke."

/s

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