Hey guys what do you think about using nukes to travel to other stars?

Orion isn't fast enough to explore out solar system.

>There is already a hole in the ozone layer.
>Shoot the rocket through the hole.
>Crisis averted.

Congratulations.
You played yourself.

fusion won't be allowed either because it has the word "nuclear" in it.

Well, liftoff is a major no-no.
This 10th of thousand tons device would have to be built in space if you don't want to loose a fucking 1000 km2 worth of land from radiation.

Think of it this way.
>1000 km of REUSABLE rocket land.

Yeah, let's launch people into space from a radioactive area.

>Launching people

Robots and materials.

Delusional/10

youtube.com/watch?v=RE16UK2o1Yk

>NUKE
>NUKE
>We come in peace
>NUKE
>NUKE
>NUKE

STOP EATING THE BAIT YOU FUCKWITS

Laser sails are a thing, and are more controllable
could turn the sun into a laser projector for interstellar ships

why?

>to prevent militarization of space

They're too far away

A solar-powered laser near the Sun and a monster Fresnel lens out beyond Neptune.
space.com/22799-interstellar-solar-sails-light-propulsion-infographic.html

Turning the Sun itself into a laser...
I saw that Isaac Arthur video too. Can't fault the man for thinking small, but....

It is the best feasible idea we have for space exploration right now. I saw a presentation by some meme scientists, you know of him, who said it would endanger us to terrorism. I don't see how it would more than nuclear subs, and nuclear subs are probably a lot easier to get at than one of these. Security is of course key, so international development is out, but a joint US military and NASA project makes sense.

It could be. You can get up to meaningful fractions of the speed of light.

You mean well, but the only way we are going to avoid extinction is to collonize space and that is going to require tech at least as dangerous as nukes.

I guarantee that you and your retarded family have absolutely no clue how nuclear technology works nor the power output compared to fossil fuels.
I bet you have an orgone buttplug in your ass as we speak.

>Gather the nuclear arch-wizards.
>Threaten to obliterate the entire planet if we are not allowed get the fuck off of it.
>Leave these plebes behind and come back a few thousand years later to obliterate the planet anyway.

My family, too, hates human progress and tries to stymie it at all levels.

Since they will be traveling on a ship with nuclear bombs firing out the other end, there is no reason why the relatively small amount of radiation would be a problem.

It would be less of a problem with some shielding.

it's the obvious way we're ever going to be able to get to other stars.

1g acceleration trips made possible by the energy density of nuclear fuels

Neither fusion nor fission pulse is a viable interstellar propulsion device. Orion does make for a readily available way to do interplanetary within very acceptable timescales though.

If we're going to the stars it's gonna be by lasersail. Only pure antimatter rockets can even remotely compete but those come with a bunch of obvious... disadvantages.

The effective exhaust velocity of nuclear pulse propulsion is usually estimated at 3000ish seconds. Aka an exhaust velocity of 30kmish/s. Aka the same deltav at mass ratio of e (2.7ish).

That's good for getting to Mars or Jupiter in weeks or months respectively, but going lightyears would still take generations.

Hippies will never allow it nowadays. We could have got away with it in the 60s if Kennedy hadn't been a pussy and kicked the USAF off the project. There are risks sure but they're not as bad as people think.

Air bursts are pretty "clean" and don't give a lot of fallout. What there is rapidly dissipates. You really only have to worry about the launch site and even that would be safe enough to go about shielded after a few hours. Plus the warheads you'd use in atmosphere are small devices, a few kilotons max. You launch in a remote area and head out over unoccupied territory and you'd be fine. Main concern isn't radiation but actually EMP effects from charged particles getting caught in the Earth's magnetic field. These effects can be minimized by launching from the right latitudes into the correct inclination but you're still going to muck things up in certain orbits for a few hours.

what fanciful idea do you have about fusion that makes you think it's so drastically different from fission?
nuclear-powered sea-going vessels just dump their irradiated water into the ocean and your complaining hasn't stopped shit, and it won't fucking stop the nuclear-powered rockets when that time comes.

They've already built and tested nuclear powered rockets, right in our atmosphere, outdoors, at ground level. Your shit didn't stop it then, it won't stop it now, it won't stop it ever. Shut up. Sit down. Take your cancer meds.
we've proven that there are more efficient ways to use nuclear fuel than just tossing nuclear bombs out the back

>nuclear-powered sea-going vessels just dump their irradiated water into the ocean and your complaining hasn't stopped shit, and it won't fucking stop the nuclear-powered rockets when that time comes.
This will only happens if the chinks decide to militarize space. Turns out the Vodkaniggers and Amerimutts were too pussy to actually build orions. There is not much immediate motivation for initial space colonization besides preventing your enemies from getting there first.

>Update

Even without nukes our air is already irradiated.
Our cells die at 1.5 million per second.
EVERYTHING IS ALREADY DEATH REEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE

At least maybe we will have a fighting chance against the odds in a world where space is just an everyday thing, as it stands now, a single barrage of meteorites and we ALL go bye bye.

>what fanciful idea do you have about fusion that makes you think it's so drastically different from fission?
Pure fusion devices in theory give a better specific impulse for Orion drives and would also result in less fallout for ground launches.

>fusion reactors are fusion bombs we could all die any second now!
>fusion reactors emmit dangerous neutrinos that pass through everything even lead and cause autism!
>fusion reactors generate heat accelerating global warming!
>fusion rockets can be set to hover over populated areas and kill people!
Fusionfags are under the delusion the hippies and whoever decides to make use of their idiocy will let them play with energetic toys. Seems history teaches nothing.

>all the art is for tiny demonstrator versions of nuclear pulse propulsion

The true benefit is that you could build a million ton vehicle, out of steel, single stage to Callisto

using nukes astern to accelerate: fine
using nukes ahead to break: bad idea

>wasting more then 95% of the explotion's energy which is already a small portion of the energy in the fuel
i dont think that shit's gonna happen

also very short bursts of very powerful radiation which means either very heavy shielding or some active shielding (which dosnt protect against everything )

Focus gets too diffuse at interstellar distances.

Try antimatter.

The direction you fire makes no difference. The exhaust still travels "away" from the ship.

Bomb propulsion does indeed waste a great deal of energy and momentum. A controlled fusion rocket would probably be much better.

Project Orion had only one advantage.
We KNOW how to build fission and fusion bombs.
We don't know how to build a fusion motor, and fission motors do even less well than bombs because we have to run them at temperatures which don't destroy the motor. Couple of thousand degrees. Bombs can expel matter at velocities equivalent to millions of degrees because they're intended to self-destruct!

That does not make them any closer.

Travelling to distant stars takes Thousands or even millions years unless (in the frame of the traveller) you're able to do it at relativistic speeds, but this would require impossible amounts of energy and would be actually hazardous, the smallest dust grain being more harmful than an atomic bomb if you hit im at more than 250000 m.s^{-1}

waste is irrelevant anyways, almost all the energy of chemical rockets is "wasted" too

efficiency is very, very important when going interstellar, as the amount of fuel you require is fucking ludicrous under the best circumstances

No, you can thank M.A.D. For that. Can anyone else not fucking stand it when talking about politics and people actually believe we are living in the most peaceful time due to democracy? Instead of you, nuclear fucking weapons?

no its a question of cost, Isp, thrust, etc
Not the amount of fuel or what useful amount of energy you can derive from each ton.

*know
>I’m not phone posting on the shitter. I swear.

The HUGE lense keeps it focused. I forget how big Forward says the lense is, but it's REALLY BIG!

Would we be capable of making a spacecraft that would be capable of accelerating at 1g half way, then decelerating the other half continuously from Earth to Mars? Could a Fusion powered ship do that?

Ever heard the term torchship? Fusion could let us build them.

Would direct thrust be better suited for this? or would using an electric propulsion system be better?

so build a relay highway for this purpose

Direct thrust all the way

If you build the ship for this purpose, you can time the pulses to give a linear acceleration feel to those onboard due to the shocks.

Waste is QUITE relevant.
Chemical rockets are barely up to achieving orbit.
They can't afford unnecessary losses. That's why all boosters nowadays use strap-on solids to minimize that initial "crawl" when thrust barely exceeds the weight of the fully-loaded booster.

But, yes, most of the energy of a rocket is "wasted" until it attains a speed comparable to it's exhaust velocity. Most of the energy in the fuel winds up as heat in the air.
That's why all schemes for rocket-powered cars, locomotives, ships, and (most) airplanes are insane.

The amount of energy you can derive from each ton IS what determines the Isp.
Some fraction of the energy released constitutes the KE of the exhaust.
"Pure" uranium fission (just expelling the fission fragments aft) would give you an exhaust velocity of a little over 4 percent of lightspeed -- an Isp of about 1 million.
To reach 10 percent of c (and stop at the far end) would take a mass-ratio of 110.

Of course, cost and thrust matter too. No point bankrupting the whole world to send a kilogram to another star in a few hundred years. No point in building a craft which could attain 20% lightspeed -- after 100,000 years of operation.

A fusion torchship MIGHT be capable of boosting all the way to Mars at 1 gee.
Image shows a 100 metric tonne (empty fuel tanks) ship going to Mars when the planets are at their closest. The drive is deuterium-tritium fusion and you start with 6 tonnes of fuel.

Total energy used during the flight -- 481 megatons (nearly ten times the Tsar Bomba!)
Energy release is 3.2 kilotons/second
That's Hiroshima every five-and-a-half seconds! You do NOT want to get in the way of the exhaust.
The power is 13.5e12 watts. ASSUME the engine is 99% efficient. Wildly optimistic!!!! That leaves you with 13.5e10 watts inside your own ship, which you have to dispose of by radiation. That's 135,000 megawatts.
For comparison, the Hanford reactor (intended to produce Plutonium) had a thermal output of 250 megawatts (two-tenths of a percent of what we're talking here) and required 30,000 US gallons of cooling water (110,000 L) per minute.
The radiators are going to be large, fragile, and likely to limit the ship to very low accelerations. The Epstein Drive, this isn't!

how do you slow down something that got accelerated by laser sail? assuming it's the first to go where it's going

If you look at the picture in you'll see the sail is ring-shaped with a small detachable center section.
Light from Earth is reflected off the ring. It gets driven to even higher velocities, but the reflected light decelerates the central payload section.

Obviously, this all takes very careful aiming.
And you don't set out until you're confident the people back home with the laser won't lose interest in the project while you're in transit.

only really deadly for the first few weeks

That is interesting, thanks.

You're welcome.
The problem with efficient rockets; i.e. those with good specific impulses and low fuel flow rates (you can see how "thrifty" is) is that momentum varies directly with the exhaust velocity, but the energy in the exhaust varies as the SQUARE of the velocity. The "ultimate" exhaust -- pure light -- carries very little momentum for the amount of energy it takes to create it. That's why flashlights don't recoil.

Larry Niven turned this into "The Kzinti Lesson". The Kzin had some sort of non-rocket space-drive and their ships could run rings around Terran craft. But the exhaust from Terran fusion motors cut the Kzin to ribbons.

>Waste is QUITE relevant.
Of course its relevant, but the optimization is for cost, not for Isp

Thats where all this nut talk about fusion drives comes from. Rather than sane practical ideas of EPP drives

Thats just one of those old sci-fi tropes of "low tech beats high tech" nonsense.

What if you made the propulsion system an open cycle? Meaning, the majority of the heat gets tossed out as the exhaust. Meaning significantly less need for radiators.

how do you dump heat into an exhaust that is millions of degrees

Nein. What I meant was to develop something like a chemical rocket. In that the exhaust IS the waste heat. All of it is being shot out of the rocket. So what I’m saying is, could we use a form of fusion propulsion that uses the same design principle. As in, shooting the plasma n sheit out the ass of the rocket to get rid of heat that way.

god user, I haven't laughed that hard in a long time

>hey guys what do you think about using nukes

What exactly are you doing on Veeky Forums then?

A generation ship with nuclear pulse propulsion is probably the only hope we'd have of surviving as a species if we detected a planetary threat.

Mass-ratio (and, therefore, cost) scales VERY rapidly if you change the Isp.

If your required dV is, say, 3 times exhaust velocity you need an R of 20.
If you switch to a less expensive fuel which only has half the exhaust velocity, R goes to 400.

Even if the cheaper fuel is only 10% of the price per lb, it's still not worth it.
It all depends on the mission parameters.
You shouldn't generalize.

When I offered those calculations, I WAS thinking open cycle where the majority of the heat goes out the exhaust. 99% efficient, remember?

Nuclear thermal rockets can't even achieve the temperatures chemical engines do. Burning H2 in O2 releases the heat IN the gas. In a fission reactor, the fuel elements and support structure must be hotter than the gas (often quite a bit hotter!) or there's no heat transfer. And you can't let your engine melt! The advantage of NTRs is the low molecular weight of the hydrogen exhaust. The molecules move much faster at a given temperature. I covered some of this in In a fusion rocket we have to assume the energy goes straight into the KE of the reaction-products, analogous to the way a chemical motor works. You use some sort of magnetic bottle with a deliberate "leak" to keep the gasses from touching the material structure of the engine. But there's nothing you can do about the EM radiation from the reaction, visible light, x-rays, and gammas. Whatever impinges on the engine is going to turn into heat. Even 99% efficiency isn't good enough when dealing with the magnitudes we're talking here.

We don't have controlled fusion, yet, so all current plans for extremely high ISPs (10s of thousands of seconds and up) are ion drives or plasma engines. They take electricity. Converting heat into electricity requires heat exchangers, turbogenerators, condensers, and it's a LOT less than 99% efficient. Typically, half the heat or more is thrown away. Thermodynamics places a strict limit on the heat-to-useful energy efficiency.
So ion drive craft are limited to low accelerations.

KE scales with the square of velocity, while Isp scales linearly with exhaust velocity
The highest possible Isp will never be the optimal choice.

Obviously we can talk about a fictional fusion torch drive, but they aren't a reality yet, nor anywhere close.

So for the foreseable future, even if an interstellar launch took a million tons of plutonium & tritium, thats how you would have to do it.

>And you can't let your engine melt!
Your engine can't melt if the fuel is already a gas.

en.wikipedia.org/wiki/Fission-fragment_rocket

>The fission-fragment rocket is a rocket engine design that directly harnesses hot nuclear fission products for thrust, as opposed to using a separate fluid as working mass. The design can, in theory, produce very high specific impulse while still being well within the abilities of current technologies.

>With exhaust velocities of 3% - 5% the speed of light and efficiencies up to 90%, the rocket should be able to achieve over 1,000,000 sec Isp.

en.wikipedia.org/wiki/Nuclear_salt-water_rocket

>A nuclear salt-water rocket (NSWR) is a theoretical type of nuclear thermal rocket which was designed by Robert Zubrin.

>The fission reaction in an NSWR is dynamic and because the reaction products are exhausted into space it doesn't have a limit on the proportion of fission fuel that reacts. In many ways this makes NSWRs like a hybrid between fission reactors and fission bombs.

>Due to their ability to harness the power of what is essentially a continuous nuclear fission explosion, NSWRs would have both very high thrust and very high exhaust velocity, meaning that the rocket would be able to accelerate quickly as well as be extremely efficient in terms of propellant usage. Such an engine being able to produce both high thrust and high ISP is a very rare trait in the rocket world

>it would be plausible to use another design which would be capable of achieving much higher exhaust velocities (4,700 km/s) and use 2,700 tonnes of highly enriched uranium salts in water to propel a 300 tonne spacecraft up to 3.6% of the speed of light.

allows the fuel to melt, and loosens the temperature limits, but the rest of the engine still has to be cooled. Note "to radiator" caption. Performance is improved, at the cost of losing tremendous amounts of expensive fissionable material -- quite a lot of which has yet to undergo fission. No one ever solved that problem, not even "lightbulb" designs.

is halfway to being an "Orion" and shares some of that concepts advantages and disadvantages. Zubrin's original plan had the reaction just BEHIND the vehicle. Your diagram looks like it's INSIDE, but additional water is injected. Either alternative "dilutes" the thrust, just as Orion does. The NSWR still has excellent performance (though 10,000 sec is "just" 100 km/sec exhaust). See image. With an assumed R of 20, initial acceleration is much less than 1 gee, and a coast period is required. No one at NASA would object to a 5 day trip to Mars! (No one except the accountants!!) Not The Expanse though.

is new to me. The Wikipedia article really doesn't explain how all the desirable characteristics are achieved without overheating the engine (though gamma and neutron absorption, if nothing else.) It also concedes "technical challenges remain". Any additional references?
"Dusty plasma" reminds me of '50s concepts where radioisotopes are thinly plated on a backing sheet and allowed to decay naturally.

, if you disagree with my assumptions, suggest a mass-ratio, exhaust velocity, initial acceleration (when the tanks are full), limiting acceleration (engine throttled back to avoid squooshing the crew), and total distance to be covered. I can run, and post, at least a few cases.

>No one at NASA would object to a 5 day trip to Mars!

stop, my penis can only get so erect.jpg

How about alternating or simultaneous fusion and fission?
Is it more possible using "fuishion"?
Is fuishion even theoretically possible?

>My family's been hardcore anti-nuke activists and we'll be fighting tooth and nail to prevent militarization of space.
Good luck with getting visa to China kek

Why do people think we would be capable of developing materials that can withstand a very close nuclear bomb detonation? That deflector plate would be all sorts of cracked and warped before we got out of our solar system. Material science is farther from developing that than we are from building warp drives.

The pusher plate is very large, the bomb is further off than you think it is, and there's no air so the only force on the plate comes from the vaporized bomb casings.

Famous case of an A-bomb set off at the bottom of a shaft. It is only an urban legend that the "manhole cover" was blown clear off the Earth. It probably vaporized from air friction. But high speed movies showed it zipping away, still intact, at several times the speed of sound,

Actual tests have shown materials can survive such blasts. Interestingly, they found a plate whose surface layer had vaporized -- except there was a raised fingerprint on the surface where the material had been left unharmed. The radiation had gone into boiling off the natural oils on someone's skin. So the plan is to "grease" the plate before a shot.

isn't it obvious? He is here to spy on us so we don't get out of line.

Here you go.

youtube.com/watch?v=uQCrPNEsQaY

>to prevent militarization of space.
Implying It's a bad thing.

What use for military would we have in space? Are we fighting Martians? Enforcing the galaxy's immigration laws?

Militarization of space mean more money in space wich is always a good thing.

A generational orion would be a viable interstellar option.

Making Mutually Assured Destruction obsolete. Which in turn. Allows whomever has in space ABM systems (lasers n shiet) invincible to nuclear strike on a strategic level. And well, if you ever wanted to get rid of all of your opponents in the game of life without bad things being inflicted upon you. That would be a good time.

I'm not talking about shitty SDI shit either. Things that were origionally designed for in space solar power, such as using lasers to beam energy back to earth to be used for electricity had the small side effect of being incredibly easy to weaponize into something that could shoot down anything with ease. We're talking 10's of MW to even GW powered fiber optic lasers essentially vaporizing any ICBM and or warheads, and even decoy's. With ease. And the best part. You can send an entire complete satellite with a laser in the range of many MW to GW in one launch. I'm actually surprised Veeky Forums and /k/ don't talk more about this.

Cassaba Howitzer

The real fun lasers and particle beams would have taken more than one launch. iirc Zenith Star, the closest the US got to a functional laser satellite would have required two. And that was supposed to just be a test rig, full power system would have required multiple launches and/or new boosters. (Rumor has it that the proposed Shuttle-C's payload bay dimensions were set partly with launching such lasers in mind)

The only system that could handle a full strike in "one launch" would be bomb pumped lasers. Essentially you can make a rod in such a way that when you hit it with a shitload of X-rays (Sourced from a nuclear bomb) it focuses the X-rays into a laser. Enough power to kill just about anything. They destroy themselves when fired but a single bomb can power dozens of lasers. They're not that big either. You can send multiple up at once on most launchers. In theory they could have crammed enough of them into a single shuttle launch and invalidated the entire soviet land based ICBM force in one go. Decoys and all.

This thread is already talking about weapons of mass destruction and genocides.

This is why nuclear is wrong - anything it promises inevitably leads to human suffering and environmental destruction.

If you consider yourself intelligent it is a crime against everything not to oppose that evil.

>caring about the people that you are genociding
I don't think you know how to properly genocide people user.