Project Orion: A discussion of Science and Science Fiction

[kerbiloid]

The fat is a hydrostatic bed to protect the internals from high acceleration from inside.

Fatter pilot - better flight.

Do not drink! Eat!

Why, do you think, the Kerbals prefer fastfood aka snacks?

The sumoists should be perfect pilots. Well-trained, relatively good heart and blood pressure, much anti-overload fat.

Just the fighter payload should be less by a 300 lb bomb.

Edited March 31, 2022 by kerbiloid

[Spacescifi]

3 hours ago, Gargamel said:

And undertall. 

I would safely wager money on the fact that a significant minority, if not a small majority of people who have been to space would be floating around.   
 

But then.... what about 65 kg of water in a (remarkably heavy) 5kg tank?   How does the gravity tell it’s working on one thing not two. What if they drink some water?   
 

This is what we keep saying.    Arbitrarily devised details in fiction create paradoxes in logic that destroy any suspension of disbelief. 

 

The water tank would be attracted of course.

The tiles detect all items touching it while touching each other as 'together' and combine their weight. So far more things would be effected than you realize.

If I were to drink a glass of water standing, the water cup would 'feel gravity) standing on the table, and also the moment I grabbed it. It would become weightless the moment I let it float in the air.

Ultimately the only time gravity would be 'off' is when even anything bounces off th floor or when someone tries to drop something.

Needless to so throwing any ball would be like neverending pong till it slows dramatically enough to just float around or rest on the ground without bouncing.

[wumpus]

On 3/30/2022 at 12:22 PM, Spacescifi said:

It was an 'experiment' to see what would really happen IRL.

Nothing in IRL is infinite, at least no mass is, but massless things at least appear to be so (time and space).

I do not like infinite with 'experiments'. It's like cheating im KSP

My point was that the limits of the 21st century are unlikely to be constraints that are even considered by the 24th.  By that point there is no reason to believe we can't efficiently throw enough argon (or whatever atom you want to yeet) at relativistic speeds out the spaceship to reach the desired thrust.  With that, you have arbitrarily large Isp and presumably enough thrust to make any passengers have to decide between length of journey and g-forces they have to withstand during said trip (possibly even using torchship means).

And yes, there are other ways to make a torchship.  I like the idea of a cyclotron flinging particles, largely because it is an extreme example of current systems (ion drives) and clearly shows that the amount of momentum you can impart on any given mass is only limited by your cyclotron.

[Terwin]

8 hours ago, Spacescifi said:

 

The water tank would be attracted of course.

The tiles detect all items touching it while touching each other as 'together' and combine their weight. So far more things would be effected than you realize.

If I were to drink a glass of water standing, the water cup would 'feel gravity) standing on the table, and also the moment I grabbed it. It would become weightless the moment I let it float in the air.

Ultimately the only time gravity would be 'off' is when even anything bounces off th floor or when someone tries to drop something.

Needless to so throwing any ball would be like neverending pong till it slows dramatically enough to just float around or rest on the ground without bouncing.

 

If items of disparate components(like a shoe or bottle of Gatorade) are combined into a single object for determining if a gravity plate will affect it, why does it not include the surrounding air?

If a 4 kg tank holding 65kg of water dissolves a couple kg of air(or co2 for carbonization) sitting on a 70kg tile, is it affected by gravity?

What if most of that co2 has left solution but is heavy enough compared to the surrounding(very still) air, to stay as a layer on top of the water?

Would a 65 kg scuba tank holding 10kg of compressed air be affected by a 70kg tile? 

What about a 69kg bath-tub that is large enough to hold 1.5m^3  (ie ~ 2 kg of air) but is open on the top?  Does a fan in the compartment cause the tub to float?

A helium filled balloon with 2kg of lifting capacity tied to a 70kg weight on a 70kg tile? 

 

The more details and stipulations you include in how something works, the more holes you open up.

In StarTrek there is grav-plating and a grav-generator, and for some reason there is a neat little zero-g area half way between the grav-generator and the main power core.

These things are not used for propulsion, presumably because impulse engines and warp drives are better.

 

Even in-world explanations like 'I don't understand why, but the scientists say that it just does not work for propulsion, and all the engineers trying to prove them wrong have failed.'  provide more detail than is really needed, but at least it does not open up any holes for the readers.

 

Plot is what should be driving all of these decisions, physics(both real and imaginary) just get in the way.

It does not matter to the story if the reason the generational ship is one-way is due to politics, financing, or physics when the MC is a 3rd generation colonist looking forward to standing on a planet for the first time in their life.

[Spacescifi]

I find it ironic how overpowered scifi can get when you mix fiction and rrality together so here goes.

 

The scenario: An orion battleship with an antigravity shield device is blasting across the sky where jetliners fly ij midair.

 

Because of the device it can float weightlessly as if it were in space even though it is only in the air.

 

Modern fighters and drones are dispatched to take it down.

The orion projects a 3 kilometer field around it that nullifies the pull of earth's gravity inside the field.

 

Upon detecting the fighters approaching the orion turns it's pusher plate in their direction and begins blast detonating.

 

Do the fighters have a realistic chance of shooting down the Orion?

If tge orion was struck deeply enough the device itself could be hit and the orion would fall out of the sky unless it used the pulse detonation to reach space.

 

I honestly think the fighters would not want this mission. It's nearly suicide.

 

This is the kind of mission you send drones on... and even then I think the nuclear EMP's might drop them too.

Edited April 7, 2022 by Spacescifi

[Shpaget]

Modern air to air missiles have quite decent range.

[kerbiloid]

A drone starts flying around the Orion making it to endlessly rotate.

[Codraroll]

8 hours ago, Spacescifi said:

Because of the device it can float weightlessly as if it were in space even though it is only in the air.

Then what does it need an Orion for? Such a device would be a vastly superior propulsion system to the heavy and clunky Orion drive. You seem to have a strange fixation for trying to fit the Orion-shaped peg into any hole no matter the size.

Also, the answer to your question: two missiles attacking simultaneously from different directions.

[Gargamel]

Hi folks!  

We've been seeing a number of threads pop up over the recent past about Project Orion, in both a scientific analysis of feasibility and uses in Science Fiction.  We have decided to merge these into one large megathread to help reduce redundancy in the discussion.  We do apologize for any overlap or confusion in the existing threads. 

Please, carry on with the current discussion de jeur, and direct any new discussions or topics that pertain to Project Orion to this thread.

Thanks!

[kerbiloid]

2 hours ago, Codraroll said:

Also, the answer to your question: two missiles attacking simultaneously from different directions.

Many orions attached to a ring.

Spoiler

Omnidirectional orion defence and artificial grafity.

Two counterrotating rings will stay on place.

51 minutes ago, Gargamel said:

We have decided to merge these into one large megathread

Orion rules! The Megathread is alive again!

Edited April 7, 2022 by kerbiloid

[wumpus]

On 12/20/2020 at 3:09 PM, Scotius said:

No. Real life Orions are cars without engines. Instead they have anvils welded to rear bumpers. You propel them forward by pulling a pin from a hand grenade and throwing it out from the rear window. Then entire assembly gets propelled forward by the shockwave and cloud of shrapnel hitting the anvil. Sounds awesome, right?

The unbearable awesomeness of Orion was that it was a fusion (or at least nuclear) powered spacecraft that could be built in the 1960s and provide capability straight out of E. E. Doc Smith.  What would make your Orion-car similarly awesome would be to build it in the middle ages.  Could you see the Connecticut Yankee smashing through knights with such a thing?  Or merely going trading between distant places while outrunning bandits?  This is most of the issue with any fixation on using pusher-craft much after mid-21st century: they are simply a primitive beast of a device that harnesses the most extreme power source available in a way that doesn't require any understanding or control of the release of such energy.  But merely by working at all the provide a massive boost in capability.

[kerbiloid]

Orion basic concept.

Spoiler

 

[Spacescifi]

On 4/7/2022 at 5:46 AM, Codraroll said:

Then what does it need an Orion for? Such a device would be a vastly superior propulsion system to the heavy and clunky Orion drive. You seem to have a strange fixation for trying to fit the Orion-shaped peg into any hole no matter the size.

Also, the answer to your question: two missiles attacking simultaneously from different directions.

 

Floating like balloon wont get you to orbit anytime soon lol.

 

But even without gravity inhibition.... project orion is literally special because unlike chemical rockets, you can SSTO massive payloads with it.

 

The price you pay is what it means to detonate nukes.... but in all honesty it simply requires small-ish super bombs, and nukes are the first we have made.

 

Who is to say futuristic bombs could be made just as powerful and small witj minimal or zero radioactive fallout.

 

Just off the top of my head there are antimatter catalyzed pure fusion bombs (only theoretical due to our immature antimatter production and storage) and metalliv hydrogen thermobaric bombs (theoretical due to metallic hydrogen production being difficult or impossible).

MH bombs would have zero radioactive fallout and antimatter catalyzed pure fusion bombs would have less than a similar yield nuke.

 

What I am getting at is the fact that chemical propellant reactions are less energy dense than superbombs.

 

Which means it requires MORE propellant for what you could actually do with LESS superbombs.

 

Try and SSTO a large spaceship with rocket engines and it would I reckon need to be huge and mostly propellant.

 

Even if you use an antimatter rocket or NSWR to SSTO I think it still be huge and necessarily larger than an orion.... and we both know Orions are not small.

 

Superbombs give you more thrust for less mass compared to rocketry.... period I believe.

 

If superbombs could be made small enough you could make star trek van size shuttlecraft.... only with pusher plates abd rocket enginrs to land.

[Terwin]

14 hours ago, Spacescifi said:

Superbombs give you more thrust for less mass compared to rocketry.... period I believe.

 

If superbombs could be made small enough you could make star trek van size shuttlecraft.... only with pusher plates abd rocket enginrs to land.

If you shrink it further, you get a fusion pulse drive or fusion torch drive.  Either of which would be far more efficient than this anitmatter-calayzed fusion Orion.

I also rather suspect that liquid helium would work much better, be far less complex, and much more possible than trying to use metallic hydrogen in fusion.

As has been explained again and again, a pusher-plate is *never* better than a rocket using the same energy source.  A pusher-plate is a low-tech way to use a small fraction of an over-powered energy source.  It was only ever considered because 1% of nuclear potential is better than 100% of chemical potential.

[JoeSchmuckatelli]

52 minutes ago, Terwin said:

It was only ever considered because 1% of nuclear potential is better than 100% of chemical potential

I wonder if that's because we only have a crude method of releasing the energy. 

Would be cool if we learned to moderate the power of of the bomb in a slower more controlled way than simply exploding it. 

[Terwin]

35 minutes ago, JoeSchmuckatelli said:

I wonder if that's because we only have a crude method of releasing the energy. 

Would be cool if we learned to moderate the power of of the bomb in a slower more controlled way than simply exploding it. 

Yes.

It is called nuclear energy, and it is very cool.  It could address all of our energy needs for centuries into the future(possibly millennia if you include fuels other than uranium), but it is also a bogey-man that will summon al NIMBY protestors within a thousand+ miles, and is regulated to the point where it is no longer cost-competitive with coal and other fossil fuels.

(one might almost see a conspiracy in that...) 

[JoeSchmuckatelli]

I'm a big fan of Nuclear Power. 

But what I don't want is a space ship with nuclear power 

I want a space ship with NUCLEAR POWER 

 

(just one that does not require using bombs) 

[kerbiloid]

We need it!

We need the New Clear Power!

Windmills, solar panels...

https://en.wikipedia.org/wiki/Ecballium

Ecballium to push the pusher plate, instead of nukes.

Spoiler

 

Plant the ecballiums onboard (in Russian - "rabid cucumber") and throw them back.

It will spit into the pusher plate and fly back.

Pure ecofriendly 100%

Edited April 10, 2022 by kerbiloid

[Spacescifi]

5 hours ago, Terwin said:

If you shrink it further, you get a fusion pulse drive or fusion torch drive.  Either of which would be far more efficient than this anitmatter-calayzed fusion Orion.

I also rather suspect that liquid helium would work much better, be far less complex, and much more possible than trying to use metallic hydrogen in fusion.

As has been explained again and again, a pusher-plate is *never* better than a rocket using the same energy source.  A pusher-plate is a low-tech way to use a small fraction of an over-powered energy source.  It was only ever considered because 1% of nuclear potential is better than 100% of chemical potential.

 

A fusion pulse drive with a magnetic nozzle is what you are referring to right?

Trying to SSTO with a magnetic nozzle may damage it since magnets do not like excess heat and atmospheric explosions tend to conduct just that.

A fusion torch drive SSTO I already implied would be probably be larger than Orion simply because it's only way to shed excess waste heat is with it's propellant during launch. Again trading payload/cargo space for propellant would occur using rocketry as opposed to orion which would allow greater payload to fuel ratios...  unless you can honestly tell me that an advanced rocket would have higher payload to fuel ration than an orion without melting it's engine.... I doubt it.

 

That is one of the main advantages of external pulse propulsion... you will never melt your 'engine'..... not for a long, long time anyway.

 

So orion may be more primitive, but it has more applications (can SSTO) and also seems to have better high payload to fuel ratios.

 

What does it matter if an advanced rocket is more fuel efficient than an Orion if it can carry less cargo than an Orion?

 

More ships is not always better if they basically fuel tanks more than anythimg else.

I would rather have a few orions with a lot of payload capacity than a bunch of fuel tanky low cargo super efficient torch drive rockets.

Orion os efficient enough and only gets more so the more super tye bomb you have.

As for metallic hydrogen, I was referring to metallic hydrogen bombs.... not fusion bombs.

If we had thermobaric metallic hydrogen bombs with shaped blasts you would not have to radiate the lower atmosphere at all... swtiching to pure fusion bombs once the air thins out high in the atmosphere.

Edited April 10, 2022 by Spacescifi

[Terwin]

1 hour ago, Spacescifi said:

So orion may be more primitive, but it has more applications (can SSTO) and also seems to have better high payload to fuel ratios.

I am pretty confident that an Orion can *not* SSTO, because if you are not in a vacuum, then a single shield plate will not protect you from the radiation of your bombs. (radiation will bounce off air molecules and sterilize your entire vessel unless you have hefty radiation armor protecting all parts of your vessel, making it too heavy to launch)

Not just radiation but hot molecules can also bounce off of ambient air and provide enough heat to your vessel(that by-passes the pusher-plate) that will bake your crew, once again sterilizing the vessel(possibly melting it) long before it can get to orbit.

Finally, the shock-waves of all those nuclear blasts will rip apart an Orion vessel in the atmosphere.  Once again, this is not something you need to worry about in space because there is no ambient atmosphere to carry the shockwaves.

Those three reasons an Orion cannot SSTO are only for traveling through an atmosphere however.

For an Orion to launch from a surface(with or without atmosphere), it will need to be protected from the radioactive shrapnel  caused by exploding a nuclear bomb on the surface of a planet.

A pusher-plate will not be sufficient to shield from radioactive surface shrapnel, so you either need lots of additional shielding, or a rocket engine to get you far enough from the surface to prevent the surface shrapnel.(making it a tsto at the very best, and even that is only on airless bodies)

 

1 hour ago, Spacescifi said:

If we had thermobaric metallic hydrogen bombs with shaped blasts you would not have to radiate the lower atmosphere at all... swtiching to pure fusion bombs once the air thins out high in the atmosphere.

Once again, we are talking about something akin to lighting a maltov cocktail behind your car for the purposes of propulsion instead of putting gas in the tank.

 

Edited April 10, 2022 by Terwin

[kerbiloid]

22 minutes ago, Spacescifi said:

magnetic nozzle may damage it since magnets do not like excess heat

Magnetic nozzles aren't magnetic.

[Spacescifi]

Scenario: SSTO project orion vessel capable of VTOL via flanking chemical rocket thrusters, then flipping in midair and using rear pusher plate blasts from HE explosives to get some distance from the ground before switching to pure fusion explosives to reach orbit.

 

Refueling the flank chemical rocket boosters: Obviously they need to be refueled or the ship cannot slow to land again.

Most Likely Space Fuel for boostersl: Ice is my guess, split into hydrogen and oxygen.

 

Most likely sources: Asteroids or comets. Moons are harder because they require landing... unless a moon base exists. In which case I suppose it could spin launch a full tank into orbit for the orbiting orion to rendezvous with, refuel and let the near empty tank deorbit with pure fusion bombs of it's own blasting off it's own pusher plate, and land using belly thruster reserve fuel.

 

Why Ice: Because LOX and LH are potent together and fairly common in space. Ice is also easier to turn liquid than other solids.

 

Other fuels: Water ice is not the only ice in space, I reckon CO2 ice and others exist on other moons. Oxidizer is often necessary for chemical rockets though, so without liquid oxygen you can almost forget VTOL with chemical rocketry. Also LOX and LH exhaust are non-toxic to humans so that is an added bonus. It's not like we are messing around with fluorine.

 

What do you think?

I think an explorer ship based on the OP would not expect moon bases to exist where it is going. Instead I would expect a minimal crew and more machinery dedicated for processing ice into liquid rocket fuels, with  different tanks for each  type. Orion blasts would still push the vessel around the solar system, but chemical rocketry would be the means to land the ship safely anywhere.

 

In fact I would expect optimization to factor in the most. So large crews would not exist except in the case of passenger liners that were taking people to a massive city in space (oneil cylinder) or for trips to and from Earth clone worlds.

Humans are resource hogs, so if you optimize for them you are bound not to be optimized for other matters in space.

Edited June 5, 2022 by Spacescifi

[magnemoe]

For mars Methane+oxygen sound smart but else hydrogen and oxygen as it only require ice+ power and is suitable for the Moon and asteroids.  
Now you can make electrolysis systems small, its an cubesat engine idea using water as fuel, you use the solar panels to split water into hydrogen and oxygen gas who you store up a bit of and then burn, repeat. Not sure how this compares to ion engines, I assume higher trust but lower ISP while still in hydrolox bracket. 

[kerbiloid]

For the Orion drive they should mine tuballoy to refine oralloy.

[Scotius]

Anything that is readily available, and offers a decent Isp. Ammonia, nitrogen, methane, water.  Titan is one big ball of hydrocarbons for example.