DOA Scifi Tropes

[Spacescifi]

Here is a not by any means complete list:

Spaceships Are NOT bought and sold like ocean vessels: An ocean vessel is mostly dangerous to other ocean vessels and ports. A spaceship is dangerous to entire planets, spacecraft and spacestations. Han Solo won't exist, anymore than he flies airliners. Professional spaceflight companies would fly spaceships, and no one would OWN a vessel unless super rich. Chartering a vessel for a mission is more likely.

Antigravity Kills Orbital Spacestations: If you have a way to fall up the need for large orbiting spacestations disappears. Orbiting satelites with sensors are always useful, but big orbiting stations no longer matter as much, since space would no longer require a massive presence, as getting up and down a planet would be easy.

 

Not DOA But Needs Work:

Orion Antimatter Triggered Nuke Pusher Plate Propulsion Are The Best Torchships: Relatively speaking. Yet the real problem is is ship and station rendezvous. Possible, but do you really want nukes going off in your ship's direction as another ship slows to dock? Realistically a ship would need plenty of propellant for docking and rendezvous in outer space. No one wants nuke blasts during docking LOL.

What I like about this drive is that it scales up and down well. Put it on a missile OR big ship. Works either way. Lots of thrust and delta v. Want months long acceleration? Payload will be small, ship would be full of bomblets. Several days of acceleration is more likely if the ship has warp or FTL, since acceleration is only needed for adjusting orbitsl trajectories anyway.

What do you think? Anything to add?

Edited September 26, 2020 by Spacescifi

[Guest]

1 hour ago, Spacescifi said:

Orion Antimatter Triggered Nuke Pusher Plate Propulsion Are The Best Torchships: Relatively speaking.

This was never a trope, just your misconception. There is no use for antimatter-initiated nukes for an Orion. Also, no type of Orion is capable of torchship-like performance. They're pretty great cargo lifters, but just don't have the performance needed for a torchship. Antimatter doesn't help. If you want antimatter-initiated pulsed fusion, that is a technology that has nothing to do with Orion.

[Vanamonde]

What's DOA stand for in this context? 

[Spacescifi]

19 minutes ago, Dragon01 said:

This was never a trope, just your misconception. There is no use for antimatter-initiated nukes for an Orion. Also, no type of Orion is capable of torchship-like performance. They're pretty great cargo lifters, but just don't have the performance needed for a torchship. Antimatter doesn't help. If you want antimatter-initiated pulsed fusion, that is a technology that has nothing to do with Orion.

1. Reread the title just above what you quoted.

Are you not aware?

tps://en.m.wikipedia.org/wiki/Antimatter-catalyzed_nuclear_pulse_propulsion

It would require scifi AM production and containment, but the scalability, thrust, and delta v are all excellent.

 

13 minutes ago, Vanamonde said:

What's DOA stand for in this context? 

Dead On Arrlval.

 

Edited September 26, 2020 by Spacescifi

[Guest]

1 hour ago, Spacescifi said:

Are you not aware?

tps://en.m.wikipedia.org/wiki/Antimatter-catalyzed_nuclear_pulse_propulsion

Read the article. This has nothing to do with Orion. This is antimatter-catalyzed microfission, and it is not a torch drive. 

It is far more complex drive than Orion, and its performance, while rather good (as with all antimatter rockets), is not on a torchship level.

[DDE]

3 hours ago, Spacescifi said:

An ocean vessel is mostly dangerous to other ocean vessels and ports. A spaceship is dangerous to entire planets, spacecraft and spacestations. Han Solo won't exist, anymore than he flies airliners.

Only if you open up a certain can of worms:

[Spacescifi]

41 minutes ago, Dragon01 said:

Read the article. This has nothing to do with Orion. This is antimatter-catalyzed microfission, and it is not a torch drive. 

It is far more complex drive than Orion, and its performance, while rather good (as with all antimatter rockets), is not on a torchship level.

 

What makes you think I have not?

The point stands that it could easily, if such tech existed, be utilized in pusher plate propulsion (especially in scifi where a lot of unknown tech advancement is taken as a sure thing).

It is the next best thing to a torchship, far better than using chemical propellant. The amount of fissile or fusile 'propellant' needed to cause a nuclear blast is much reduced, enabling smaller bombs just as powerful if not more so than normal nukes that take up more volume. That is why the thrust and delta v is so good.

Besides... in space opera they have warp/FTL, so AM catalyzed nuclear pusher plates would be like using the wheel (old but efficient propulsion method).

Warp gets you close enough fast, pusher plate will allow you to change trajectories so you can actually land or whatsoever in a reasonable amount of time.

20 minutes ago, DDE said:

Only if you open up a certain can of worms:

 

I wish... even at sublight velocities plenty of damage can be done. That is why civillians will never own starships in scifi... unless orbital defenses are overpowered enough to blast them to space dust in millseconds.

Any large spaceship is automatic WMD, even at lower velocities.

Edited September 26, 2020 by Spacescifi

[Guest]

1 minute ago, Spacescifi said:

The point stands that it could easily, if such tech existed, be utilized in pusher plate propulsion (especially in scifi where a lot of unknown tech advancement is is taken as sure thing).

It could, and it would also be a very stupid thing to do. The whole point of microfusion/fission is to use small, controllable, low-yield explosions that could be funneled through a magnetic nozzle. If you use a pusher plate, you'll have the exact same performance as an Orion, only with lighter (but absurdly expensive) pulse units. It's important to understand that antimatter, in those drives, only ignites the nuclear reaction. It contributes to thrust, but not very much, and it definitely doesn't make it any more energetic.

AM-catalyzed Orion would be like powering a Tesla truck by making a horse run on a treadmill placed on the bed. Overcomplicated, inefficient and pointless. The whole point of a pusher plate is to allow the use of full-sized nuclear devices. The whole point of AIM/ACMF is to allow the use of pulse units smaller than a full-sized nuke. Combining the two defeats the point of either.

Pusher plates are not efficient at all. In fact, they're really inefficient. Old tech is almost never really efficient (it might be reliable and/or cheap), and Orion is ridiculously primitive even today, nevermind in a futuristic civilization.

[Spacescifi]

10 minutes ago, Dragon01 said:

It could, and it would also be a very stupid thing to do. The whole point of microfusion/fission is to use small, controllable, low-yield explosions that could be funneled through a magnetic nozzle. If you use a pusher plate, you'll have the exact same performance as an Orion, only with lighter (but absurdly expensive) pulse units. It's important to understand that antimatter, in those drives, only ignites the nuclear reaction. It contributes to thrust, but not very much, and it definitely doesn't make it any more energetic.

AM-catalyzed Orion would be like powering a Tesla truck by making a horse run on a treadmill placed on the bed. Overcomplicated, inefficient and pointless. The whole point of a pusher plate is to allow the use of full-sized nuclear devices. The whole point of AIM/ACMF is to allow the use of pulse units smaller than a full-sized nuke. Combining the two defeats the point of either.

Pusher plates are not efficient at all. In fact, they're really inefficient. Old tech is almost never really efficient (it might be reliable and/or cheap), and Orion is ridiculously primitive even today, nevermind in a futuristic civilization.

 

Absurdly expensive? Not in scifi! FTL/warp starfleet man!

Good points you make though. As I said civillians won't own this type of thing.

Magnetic nozzle is okay-ish, but the pusher plate is more versatile.

Like if for some reason I wanted to use the pusher plate in an atmosphere I could... not so with a magnetic nozzle. It would ruin it.

Old, reliable and versatlie is good enough for me though.

Also advanced tech may allow the small pellets to make shaped explosions too.

Edited September 26, 2020 by Spacescifi

[Nuke]

letting everyone have an interstellar capable space ship is a lot like letting everyone carry their own nuclear weapons. even intra system torch ships can pose a threat. you might have a dune like situation where everyone can have slower than light ships, but the ftl ships are controlled by an entity who's interests lean to the non-destructive. 

[DerekL1963]

4 hours ago, Spacescifi said:

Spaceships Are NOT bought and sold like ocean vessels: An ocean vessel is mostly dangerous to other ocean vessels and ports. A spaceship is dangerous to entire planets, spacecraft and spacestations. Han Solo won't exist, anymore than he flies airliners. Professional spaceflight companies would fly spaceships, and no one would OWN a vessel unless super rich. Chartering a vessel for a mission is more likely.

Yeah, no.  Dangerous is dangerous.  If an ocean vessel, which is a threat to a port where millions of people can live, are legal to own - then it doesn't make sense to limit the ownership of spacecraft on the same basis.  (You're forgetting the cargo shipmate - that's a much larger threat than the hull itself.)  And there's marginal shipping companies aplenty moving dangerous cargos across the oceans.   (One such finally got caught, and it was their seized and improperly stored cargo that took a chunk out of Beirut recently.)

And when it comes to Han Solo, same mistake.  There's plenty of airliners and large bizjets in private hands.

[Guest]

3 minutes ago, DerekL1963 said:

And when it comes to Han Solo, same mistake.  There's plenty of airliners and large bizjets in private hands.

Actually, most airliners are in private hands. It's just that the entities owning them are nearly always large companies, which use them to do business, and have appropriate (for most part) regulatory oversight. It is very rare for a plane of significant size to be actually reserved for the owner's personal use, and every one of those owners is very wealthy. Han Solo was hardly one of those types.

Ocean vessels big enough to pose a threat, especially ones transporting dangerous cargo, are owned by companies, too, and receive a lot of oversight. Sure, sometimes such a company goes out of business, and then a dangerous cargo might end up with unclear legal status, but this is a relatively uncommon event. Again, personal freighters are not really a thing. Owning a 100m+ yachts is a privilege of ultra-rich, and they're usually not involved in how these ships run, beyond telling the captain where to go. They don't carry any cargo, either, and are only dangerous to smaller vessels that happen to blunder into their path.

I'd expect starships to be the same. Large, expensive, ran by large companies. No space swashbucklers and space pirates. No smuggling, either, unless as a side business of an otherwise legitimate commercial ship operation. There are ways to be sneaky in space, but not for a simple freighter on a regular basis, so a smuggler would need a legitimate reason to come and go, at least. Occasionally, some billionaire could have one for personal use. 

[Spacescifi]

25 minutes ago, DerekL1963 said:

Yeah, no.  Dangerous is dangerous.  If an ocean vessel, which is a threat to a port where millions of people can live, are legal to own - then it doesn't make sense to limit the ownership of spacecraft on the same basis.  (You're forgetting the cargo shipmate - that's a much larger threat than the hull itself.)  And there's marginal shipping companies aplenty moving dangerous cargos across the oceans.   (One such finally got caught, and it was their seized and improperly stored cargo that took a chunk out of Beirut recently.)

And when it comes to Han Solo, same mistake.  There's plenty of airliners and large bizjets in private hands.

 

Well... there is a danger, and then there is WMD danger. Whole. Nother (I know grammar, did that on purpose). Level.

A spaceship using orion AM ignited fusion bombs is an order of magnitude more dangerous than most ocean vessels (excluding nuke missile carrying subs). That is why commoners owning them seems unlikely.

As for private ownership, those tend to be rich guys/gals. So I don't even disagree, inasmuch the rich are the minority anyway.  Han Solo might be a charismatic Captain of a large chartered freighter, but he surely won't own it, anymore than a cruise ship captain does.

[Guest]

If you want civilian ownership, this creates another reason why AM-ignited Orion is a ridiculous idea (leaving aside that no profit-oriented company would waste antimatter like that). This type of drive relies on bombs, which are easy to weaponize, to say the least. Such a thing would likely be never allowed to exist in civilian hands. Really, just use a direct fusion drive or any other sensible, continuous thrust technology such as DFD, flow-stabilized Z-pinch or, if you really want antimatter, plasma core thermal. The latter is very much a viable torchship drive. Not only they would have better performance, they would be harder to use as outright weapons. 

Edited September 26, 2020 by Guest

[Spacescifi]

1 hour ago, Dragon01 said:

If you want civilian ownership, this creates another reason why AM-ignited Orion is a ridiculous idea (leaving aside that no profit-oriented company would waste antimatter like that). This type of drive relies on bombs, which are easy to weaponize, to say the least. Such a thing would likely be never allowed to exist in civilian hands. Really, just use a direct fusion drive or any other sensible, continuous thrust technology such as DFD, flow-stabilized Z-pinch or, if you really want antimatter, plasma core thermal. The latter is very much a viable torchship drive. Not only they would have better performance, they would be harder to use as outright weapons. 

Here even I agree with you... AM may have awesome applications but surely there must be another way in scifi.

Direct Fusion Drive is kind of weaksauce for my purposes. The flow stabilized Z pinch scientists find unstable, which either means they cannot, cannot yet, or are doing it wrong. Time will tell.

What is my purpose?

Antigravity I guess. You really need nothing else except for asteroids, and for that nuclear thermal propellant can suffice. They have antigravity to repel away from planets. It is possible to warp around a planet and either repel away or fall toward it, then rinse and repeat and attain any trajectory one wants.

 

Can antigravity be used as a weapon? You bet it can! But it won't be explosive unless an author wishes...  per the fact that they are purely fictional devices so far.

Edited September 27, 2020 by Spacescifi

[kerbiloid]

I believe, the antimatter-powered pusher-plate micro-orion RCS thrusters would help a lot on the docking operations.

[satnet]

Here's the thing with sci-fi: You can get just about any concept to make sense with the right rules for your fictional world. No concept is truly DOA, though some things require more work than others to make believable. Your list definitely has concepts that require a fair amount of work to really make sense, but it isn't impossible.

For example:

1. Private ownership of starships - If "planetary shields" are a thing you could allow private ownership because you now have a defense (of course now you need to explain how shields can exist). There is also the option of doing something like Babylon 5 where non-military ships require well controlled jumpgates rather than being able to achieve high speeds on their own.

2. Anti-gravity and spacestations - If anti-gravity fields require a lot of power then space stations can still make sense. It really depends on the rules you create for your anti-gravity drive whether it really kills space stations. You can also make a plausible case for space stations as orbital habitats (maybe to handle overpopulation or just to give humanity a backup option) even if anti-gravity makes it easy to get to orbit.

Having said that, good science fiction extrapolates from existing science to a place that is logical enough that it doesn't require a lot of explanation to to achieve "suspension of disbelief". There are certainly a lot of tropes in science fiction that are extremely common, but actually don't make a lot of sense based on current science. These are usually because they were tropes before the science was established or more often because they fix a common need in narrative story telling.

Examples:

1. FTL - While there are some vague theories about how this can be achieved, most require negative energy and other things that may simply not exist. It does however make it plausible for the same crew to see more than one planet in their lifetime, so we generally accept it.

2. Transporters (Matter->Energy->Matter type) - The Heisenburg uncertainty principle makes this highly unlikely. The fact that this involves containing the same energy as a matter/anti-matter detonation of equivalent mass also stretches credibility. Star Trek at least had the Heisenburg compensators as a nod to those in the audience who knew why it probably wouldn't work.

3. Telepathy  - The idea of one brain naturally interfacing with another is pretty far-fetched. Doing it wirelessly is even more so. I will however give Babylon 5 credit for having a semi-plausible explanation (direct genetic manipulation by a more advanced species rather than a naturally emerging trait).

4. Energy Shields - We know of nothing that could allow anything like an energy shield to exist. They do however make it possible to have space battles that aren't just ships firing missiles beyond visual range at one another (though the Expanse proves that can be cool too if you know what you're doing).

5. Knew elements with fantastic properties - No matter what planet you're on the atomic elements are the same (different ratios for certain, but the same elements). You aren't going to another planet and finding new elements, that will probably happen in a lab. If the proposed "island of stability" exists you might be able to create heavier elements, but they will almost certainly have the properties you can extrapolate from their position on the periodic table. Also my recollection is that the stability is relative and they are still short lived, just not the femtosecond lifetime you might expect. You can definitely get some materials with unexpected properties, but the trope is usually a new atomic element.

Really you need to keep your audience engaged and keep from pulling them out of the story while they try to make sense of your concept. This usually means not straying too far from the rules we have come to know in our everyday lives with some plausible extrapolations. You should also try to avoid creating rules that contradict existing laws (over-unity energy production for example). Probably more than anything you need to be internally consistent (once a rule is introduced don't change it) and you should probably avoid creating rules that obviously only exist purely to satisfy the needs of your narrative.

[kerbiloid]

Before discussing the "private starships", can somebody explain at least what does it mean: "private", in the society where the starships are so cheap and common that can be "private"?

***

The term "private" has any sense when there is some property to be exchanged. Till now it basically means that you produce something to exchange it for food, clothes, habitat, etc.

When the starships are enough cheap to be "private", this means that everything listed above (food, clothes, habitat, transport, entertainment) is almost free, as their production is much cheaper and easier than the starships.

Also this means that noone can produce any significant value,  so actually it means that almost everything used by everybody is distributed for free rather than sold.

So, if define the "property", "private" as "a value owned by the person", this means that no person actually has an owned value. "You" get everything for free, paying only by your societal loyalty.
If somebody takes it from "you", it's even not a stealing or robbery, it's just a profanity, as "you" just go and take another such thing instead of the taken from you, loosing nothing.

In such society the "property" and "private" just make no sense, only "societal influence" exists. If you are an important societal influencer, you can manage the starship missions, but the starships cannot be "yours" because you cannot exchange them, just because others don't have anything same significant to exchange, and you don't have as well, to exchange this for a starship.

Actually this means the death of "money", "property", "owner", "private" and other such entities in whole.

***

So, you can be a Second Grand Regional Supercargo managing two starships owned by the Regional Commonship, but can't own them, and they can't be "private".

Edited September 27, 2020 by kerbiloid

[KSK]

14 hours ago, Spacescifi said:

Here is a not by any means complete list:

Antigravity Kills Orbital Spacestations: If you have a way to fall up the need for large orbiting spacestations disappears. Orbiting satelites with sensors are always useful, but big orbiting stations no longer matter as much, since space would no longer require a massive presence, as getting up and down a planet would be easy.

I'm not going to go around the antimatter fanservice loop yet again since that's come up on several previous threads.

But antigravity killing orbital space stations is... a limited viewpoint in my opinion. Some possible uses of large space stations even assuming antigravity is a thing.

• Zero G manufacturing.  Another well-trodden sci-fi trope and made more plausible if there was a cheap, easy and clean way of transferring material in bulk to and from orbit. Like vehicles equipped with antigravity devices for example.
• Space Embassy /Observation / cultural non-interference/Deathworld.  Any setting appropriate reason why landing a spacecraft on another planet could be seen as provocative to the inhabitants of that planet or dangerous to the spacecraft crew. Instead you have an embassy in orbit.
• Tourism/real estate.  People living in orbit for sociological reasons - status, curiosity or simply a lack of living space on the surface. Again, reasons that are made much more plausible by cheap and easy and clean access to orbit.
• Remote control of facilities on the surface. Found a planet which is full of valuable ores but totally inhospitable to humans? Send down the robo-miners and stick a teleoperation station in orbit to supervise them.
• Automated refueling stations. Exploring a star system with reaction drives? It might be a good idea to build some infrastructure ahead of time, so that your survey teams can refuel and get home again. Very dependent on limitations you choose to put on your antigravity systems but if your mothership is too big to land then refueling it in orbit becomes your only option.

Also, a sufficiently large spacecraft could be regarded as a space station with engines if you can't get it to the surface, even with antigravity lifters. Here we're getting into the realms of Iain M Bank's Culture novels where an entire interstellar civilization lives in space, whether that's in gigantic spacecraft or orbital habitats of various kinds.

More generally, from participating in several of your threads, you seem to have a fixation on the notion of a single ship that can do it all - take off from one planet, travel somewhere else at a plot convenient speed and then land on another planet. If that's the setting you want to to work in that's great - and in such a setting, antigravity may well make space stations obsolete. For other settings - not so much.

[Codraroll]

Antimatter in general. If you have the means to make it, you don't need it.

 

But yeah, what @satnet said. It's sci-fi. Fiction. You can have your setting make use of whatever you want. If you want FTL ships that run on algae grown in vats onboard, you can have that. Take some liberties, that's literally what sci-fi is all about.

[Spacescifi]

6 hours ago, KSK said:

 

More generally, from participating in several of your threads, you seem to have a fixation on the notion of a single ship that can do it all - take off from one planet, travel somewhere else at a plot convenient speed and then land on another planet. If that's the setting you want to to work in that's great - and in such a setting, antigravity may well make space stations obsolete. For other settings - not so much.

 

Exactly true.

I like the lone starship exploring the galaxy trope.

Apply modern tech and it simply falls apart since:

1. First you send drones if possible or a drone ship to an unexplored system... actually that's a good idea, since if nothing is of interest then why send a manned mission over? Indeed, if the drone finds a planet rich in diamonds or made or platinum or something then yeah... send a manned mission and set up an ore extraction base and export port. Or if there is life, observe and report back to starfleet in deep space, which then report back to homeworld. That prevents dangerous stuff from piggybacking all the way back to homeworld.

2. Realism with reaction propellant drives would require a whole fleet, or a big vessel with parasite craft, nothing more, nothing less. In fact, a lot of time would be spent simply waiting while refueling off ice from comets or water from planets as much propellant would be burned through. Which is kinda boring for the plot if you ask me.

[sevenperforce]

10 hours ago, kerbiloid said:

I believe, the antimatter-powered pusher-plate micro-orion RCS thrusters would help a lot on the docking operations.

I feel like that is a good idea, but what we should REALLY do is give Starship gluon-plasma-triggered pusher-plate nano-Orion ullage thrusters to save RCS propellant.

18 hours ago, Dragon01 said:

Pusher plates are not efficient at all. In fact, they're really inefficient. Old tech is almost never really efficient (it might be reliable and/or cheap), and Orion is ridiculously primitive even today, nevermind in a futuristic civilization.

Yep, this.

Pusher plate designs were proposed ONLY because of technological limitations on the containment of thermonuclear weapons. They are extraordinarily inefficient.

A pusher-plate spaceship is like running a train by having Superman sit in the engine and use his heat vision to boil water to make steam. It’s technically more efficient than running a steam engine on coal, but that’s about it. 

[Spacescifi]

6 minutes ago, sevenperforce said:

I feel like that is a good idea, but what we should REALLY do is give Starship gluon-plasma-triggered pusher-plate nano-Orion ullage thrusters to save RCS propellant.

 

It would be a good idea if the ship is truly massive, to the point where the amount of propellant spent doing attitude adjustment is very inefficient.

 

It is interesting that there IS a weight limit to how heavy one can make starships even if we could repel away from planets with antigravity.

 

Namely once your ship is so heavy that nuclear pusher plates are the most efficient RCS you can use... we have gone too heavy.... way too heavy LOL.

 

How heavy would auch a vessel be anyway?

Star Destroyer heavy?

Given a calculated volume of about 54,000,000m³ for Star Destroyers at 1600m length, and a density range of 500-1000kg/m³, the mass of a Star Destroyer should fall somewhere between 27,000,000,000 and 54,000,000,000 kilograms. That's 27 to 54 million metric tonnes.Jan 21, 2010

 

Edited September 27, 2020 by Spacescifi

[kerbiloid]

As anyway a superstarship using any modern technology becomes a Superman-like entity, it's better just to use a Superman. He doesn't need a ship at all and still is same sciencish as the superstarship.

Edited September 27, 2020 by kerbiloid

[Guest]

1 hour ago, Spacescifi said:

It would be a good idea if the ship is truly massive, to the point where the amount of propellant spent doing attitude adjustment is very inefficient.

It would be an idiotic idea, and you failed to see the sarcasm. Leaving aside obvious technobabble, low frequency pulsed engines are useless as RCS, because their minimum impulse is large. You simply cannot, by definition, have any sort of fine control with such a drive.

If you have the technology level that you want to have, pusher plate is the worst option available to you. I don't know why you insist on using it. Orion is a very primitive way of making an efficient spaceship, but it's a technological dead end. 

Edited September 27, 2020 by Guest