Is Science Fiction Losing Its Charm Due to Unrealistic Space Travel?

[SHISHKABOB]

What do you mean? Why would it be a problem to just aim, accelerate it up to a high fraction of C and watch the fire works? If long distance is a problem add some form of sensor and some thrusters to tweak the course. Even a small fraction of a degree course change could have big consequences after light hours-years

this may be a misunderstanding on my part, but wouldn't it take a looot of energy to change the course of something moving extremely fast?

 

[Ryan_m_b]

this may be a misunderstanding on my part, but wouldn't it take a looot of energy to change the course of something moving extremely fast?

Kind of, by engaging in any kind of thrust you change the velocity. Simplistically think of two objects on a grid: A and B with the top being North, bottom South etc.

A is traveling north at a speed of 1 square per second. B is traveling north at a speed of 10 squares per second. Both of them apply thrust so that they are moving west at 1 square per second. For A this means that for every square it travels north it travels 1 west (creating a 45 degree angle if this grid were a graph). For B it travels 1 square west for every 10 north.

However you only have to nudge a tiny bit to be very off course over long distances. Let's posit B (a RKV now) traveling at 150,000,000 mps (~0.5c) and at some point it thrusts to one side (let's say port) so that it is traveling 1 metre to port for every 150,000,000 metres it travels forward. Over the course of a light hour (two hours of travel) it is now 3.6 km off course to port. Over a light year it would be 62,000 km off course!

And that is only supposing it sticks to the measly thrust that generates 1mps to port!

 

[SHISHKABOB]

right, I see now. Usually I imagine relativistic weapons as big chunks of stuff that don't have thrusters on them, but I guess it isn't unreasonable to put things like that on something like that.

 

[Ryan_m_b]

right, I see now. Usually I imagine relativistic weapons as big chunks of stuff that don't have thrusters on them, but I guess it isn't unreasonable to put things like that on something like that.

Without propulsion how do you get them up to relativistic speeds ? For me an RKV is just a spaceship on autopilot; the only difference between a relativistic spaceship and a weapon is how it plans to end its journey.

 

[SHISHKABOB]

well, perhaps you have some kind of accelerator like a railgun, but I can see how making it basically a spaceship makes more sense. Well, a lot more sense :P

 

[GTOM]

Although I am wondering.
Isnt it possible, that with this speed, collision with gas particles and micrometeors, electromagnetic induction from solar wind and magnetic field, will ruin its sensor arrays inside the Solar System?
Than it can still miss the Earth.

 

[Ryan_m_b]

Although I am wondering.
Isnt it possible, that with this speed, collision with gas particles and micrometeors, electromagnetic induction from solar wind and magnetic field, will ruin its sensor arrays inside the Solar System?
Than it can still miss the Earth.

Doubtful, space is incredibly empty, but even if it did all it would take is an accelerometer to sense course changes and an internal map built up from before it went blind would ensure it hit.

 

[GTOM]

I see.

What is your opinion about space fighter carriers?
I know that small ships and big ships moving through the same void... but i had the thought, that theoretically, we could convert our ships to huge airships, but it would be too expensive.

Maybe, for someone, it would be too expensive to fit an interplanetary cruiser with special lower specific impulse-high trust drives and super cooling mechanisms that can grant a fighter superior acceleration on a bigger scale than a not so special interplanetary ship.

I know you can't just dodge lasers and other beam weapons... but it isn't that easy to hit small flies, not even for a computer.

 

[rolerbe]

I like the whoooshing sounds they make. My favorite part!

 

[Ryan_m_b]

What is your opinion about space fighter carriers?
I know that small ships and big ships moving through the same void... but i had the thought, that theoretically, we could convert our ships to huge airships, but it would be too expensive.

Huh? You mean turn aircraft carriers into blips? Firstly that would be one huge balloon and secondly a couple of bullets in that balloon and you're going to have a bad day.

Regarding the fighter/carrier idea it really depends on the technology you have available. Put it this way if you had something like a VASIMR or fusion drive you are going to need to carry a honking great power plant (probably nuclear) to run it. Plus all the fuel, expendables etc means that for anything that you want to be able to operate for more than a few minutes it's going to have to be big. So that's a large amount of specific impulse but low thrust.

Conversely a "fighter" is so small that all it could fit is some sort of chemical drive which massively reduces it's specific impulse but might increase it's thrust. Problem is in what scenario is that helpful? It's hard to know without having a hypothetical military scenario on the table and a list of technologies.

 

[GTOM]

"You mean turn aircraft carriers into blips? Firstly that would be one huge moon and secondly a couple of bullets in that balloon and you're going to have a bad day."

Turn regular ships into airships with many rotors. They wouldn't sink if they hit their belly, subs with torpedos don't threat them, they could cross the ocean faster...
At least I think, its theoretically isn't impossible, but that would be too expensive...

So it might be possible to have similar analogy with space fighters and carriers.


Historically, they started to build torpedo boats against dreadnoughts.
They doing research, to decrease a TeraWatt lasers cooldown time to some hours...
So a dreadnought with a giant cannon won't be effective against a fighter swarm, they can get close to deliver a fatal blow with particle cannons. /Of course after the shot there is hours long cooldown and recharge time/
Well destroyers was meant to counter subs and torpedo boats.
But space fighters don't simply sink, and they could be used for flanking operations together with frigates, that can take out the destroyers with their cannons. Of course that requires careful planning with fleet operations.

Well I don't say this combo is superior to dreadnought and destroyers combo... but in war, you can't choose every time, what is the best thing, you use what you got.

Otherwise i don't argue, that space fighters are primarly meant to be brown water navy, fighting in giant shafts of asteroid mines and moonbases could be their special mission.

 

[Ryan_m_b]

Turn regular ships into airships with many rotors. They wouldn't sink if they hit their belly, subs with torpedos don't threat them, they could cross the ocean faster...
At least I think, its theoretically isn't impossible, but that would be too expensive...

The amount of power and rotors would be gargantuan and it would still be fragile. Also, what's the point? Aircraft carriers exist to grant a mobile refuelling base for aircraft so as to extend their operational range and response time. There would be little advantage to having a flying aircraft carrier

Historically, they started to build torpedo boats against dreadnoughts.
They doing research, to decrease a TeraWatt lasers cooldown time to some hours...
So a dreadnought with a giant cannon won't be effective against a fighter swarm, they can get close to deliver a fatal blow with particle cannons. /Of course after the shot there is hours long cooldown and recharge time/
Well destroyers was meant to counter subs and torpedo boats.
But space fighters don't simply sink, and they could be used for flanking operations together with frigates, that can take out the destroyers with their cannons. Of course that requires careful planning with fleet operations.

Well I don't say this combo is superior to dreadnought and destroyers combo... but in war, you can't choose every time, what is the best thing, you use what you got.

Otherwise i don't argue, that space fighters are primarly meant to be brown water navy, fighting in giant shafts of asteroid mines and moonbases could be their special mission.

I'll refer to my previous point about needing to know a military scenario and technology to have a proper exploration of the issue but I can't think of any reason why someone would fly down an "asteroid shaft" anymore than an aircraft on Earth would try to fly into a cave.

 

[GTOM]

"I can't think of any reason why someone would fly down an "asteroid shaft" anymore than an aircraft on Earth would try to fly into a cave."

Well, maybe i played too much with this :

http://en.wikipedia.org/wiki/Descent_(video_game )

Asteroid mines can be the valuable things you want to capture. Maybe the whole war is about the resources of asteroids and moons. /Stroming a planet isn't such a good idea.../
The shafts can be so giant /as you don't need to reinforce them in low or zero gravity/ that small ships can manuever in them.

"The amount of power and rotors would be gargantuan and it would still be fragile. Also, what's the point? Aircraft carriers exist to grant a mobile refuelling base for aircraft so as to extend their operational range and response time."

That is my point for space fighter carriers, if the fighter squadrons can take out enemy capital ships with the focus fire of their cannons, no need to convert an entire huge interplanetary ship to a fast nimbe battle platform.
Of course that supposes that long-range missiles arent the best choices, due to enemy defences, but lasers don't always hit from a big range.

It is maybe a bit paradox. My main point against long-range missiles, that one can launch several interceptor missiles, mines against one, and they have to enter into point blank range of defences. Fighters can protect themselves from missile weapons with their lasers and agility to dodge shrapnels, and they can fire from 100.000 km. From that range one tenth arcsecond of error in targeting (limited sensor accuracy, light lag, random acceleration, tiny errors in tracking device) mean a 50m miss.

Of course that is purely speculative. I just wondered is it so lame to justify carriers with theese reasons? Like you said, it is lame to justify fighters with targeting role.

 

[Ryan_m_b]

(Just so you know when you want to quite someone just press the quote button in the bottom right)

Asteroid mines can be the valuable things you want to capture. Maybe the whole war is about the resources of asteroids and moons. /Stroming a planet isn't such a good idea.../
The shafts can be so giant /as you don't need to reinforce them in low or zero gravity/ that small ships can manuever in them.

Assuming you did want to capture an asteroid a crawling bot or person in a suit would be better. The amount of fuel you would have to use to change course, direction etc would be prohibitive and unless it's anchored to something the slightest nudge and it could go spinning away.

It is maybe a bit paradox. My main point against long-range missiles, that one can launch several interceptor missiles, mines against one, and they have to enter into point blank range of defences. Fighters can protect themselves from missile weapons with their lasers and agility to dodge shrapnels, and they can fire from 100.000 km. From that range one tenth arcsecond of error in targeting (limited sensor accuracy, light lag, random acceleration, tiny errors in tracking device) mean a 50m miss.

Advantages of a missile is what you can cram inside (rather than a cockpit, air, controls etc just have countermeasures and explosives), they could achieve much higher g-forces, it is less of an issue when they get hit etc.

Also I don't agree with your advantages of a fighter for "firing 100,000km away" what exactly are they firing and why couldn't a long range missile also be equipped with a weapon?

 

[GTOM]

Assuming you did want to capture an asteroid a crawling bot or person in a suit would be better.

Well of course men are also required to capture and hold that mine, but the ships can help them, like a helicopter, or river boat can support ground troops IMHO.

Advantages of a missile is what you can cram inside (rather than a cockpit, air, controls etc just have countermeasures and explosives), they could achieve much higher g-forces, it is less of an issue when they get hit etc.
Also I don't agree with your advantages of a fighter for "firing 100,000km away" what exactly are they firing and why couldn't a long range missile also be equipped with a weapon?

Well, i can't really argue, that in deep space, drone level intelligence and remote control is enough, but i prefer to call that platform an unmanned, remote controlled fighter, I think this platform is more intelligent to be called simply missile.
It can be preferable to make it reusable, in more difficult situations (like the one i mentioned in the first paragraph, and orbital platform where civilans neutral parties and valuable infrastructure can be involved) it should be manned. In deep space it can be launched remote controlled, you could fill the cockpit not with oxigen, but an additional fuel tank, or coolant, heat sink, or something like that. Of course that requires sophisticated engineering.
It could fire a relativistic particle beam for example, short range, high punch. (Long charge and cooldown time.)

 

[GTOM]

Well, maybe any more suggestions what can be a good book?
I saw another thread, but that was about movies.

 

[GTOM]

Well someone recommended Ian Douglas, is it a "hard" sci?
At first blink it seemed to project near-past wars to space.

 

[Travis_King]

I particularly like the way Asimov creates these great ideas that seem perfect, and then works throughout his novels proving himself wrong. He creates a set of laws which seem to be the perfect answer to keeping robots in check, then systematically cuts them down with loopholes. Genius.

As to the original topic, yea. I really enjoyed the new Battlestar Galactica, but I cringed whenver I saw one of them doing their crazy little flip-spin-turns.

Though, admittedly, with a powerful enough propulsion system which doesn't devour fuel, you could conceivably pull something like these maneuvers, assuming your relative velocity to the stuff around you doesn't change (that is, if your ship and the ship you are fighting are in the same ballpark as far as velocity goes. If you could counteract the acelleration forces on the body and have directional jets with enough specific impulse to stop you quickly, I don't see why rapid changes of direction and speed would not be possible. I don't think they'd be economical though.

If you want a writer who's got this bit sorted out, read The Lost Fleet series by Jack Campbell. This is hands down the best space-fleet combat I've read. It takes the spaceship combat action from an angle of how it might actually be like. I highly recommend it. [Edit: FYI, if you can't read a book without in-depth character development, then this may not be the book/series for you. I enjoyed the military planning, execution, and battle descriptions, more so than the development of the, admittedly, somewhat 2D characters]

 

[Ryan_m_b]

If you want a writer who's got this bit sorted out, read The Lost Fleet series by Jack Campbell. This is hands down the best space-fleet combat I've read. It takes the spaceship combat action from an angle of how it might actually be like. I highly recommend it.

I'm a fan of the lost fleet series but I disagree with this; the combat is far better thought out than soft science fiction however it still relies on soft-SF handwavium like inertial negation, impossibly powerful propulsion, force fields and a lot of the explanations for limitations don't really stack up like ships not being able to engage at closing speeds of more than 0.2c because relativistic distortion will mess with the sensors.

IMO the Dread Empire Fall trilogy dealt with it better, it still involves some handwavium (copious amounts of antimatter) but the ships can only accelerate at the limit that their occupants can safely handle and the tactics of formations in 3d are very clever. For example; ships conventionally remain close to maximise their close-in defence against missiles but because of this they are in danger of catastrophe once one ship gets hit and it's antimatter is released. To combat this various patterns are formed that maximise defence but allow the ships to move around erratically.

In fact those two series are very interesting in how similar yet how different they are.

 

[Travis_King]

I forgot about the forcefields...
Dread Empire Fall, huh? I'll have to take a look. I really enjoyed the "naval" formations in the LF series, I thought Campbell did a great job of painting the picture in 3D and allowing you to visualize from/to where the attacks were coming and going.

There's got to be some handwaving haha, in real life I imagine it would pretty much just be both ships blowing each other up once they found their location and trajectory. I suppose some evasive maneuvers could be used, but really I think it would be pretty anticlimactic.

 

[Ryan_m_b]

I forgot about the forcefields...

I'll give Campbell his credit, he doesn't make the mistake of trying to explain his handwavium. Ships have forcefields, they accelerate to significant fractions of c in no time at all and that's that.

Dread Empire Fall, huh? I'll have to take a look.

It has it's flaws but it's worth a look. Especially to compare to LF.

There's got to be some handwaving haha, in real life I imagine it would pretty much just be both ships blowing each other up once they found their location and trajectory. I suppose some evasive maneuvers could be used, but really I think it would be pretty anticlimactic.

It really relies on what technology is available and what the military goal is. Realistically however if it happens in the future it's not going to be anything resembling dog fights or naval fleets.

 

[ImaLooser]

Lol yeah I reckon if I had read it when I was younger I could have just enjoyed it (and I did enjoy the lot of it but that enjoyment faded over time).

"The Golden Age of science fiction is fourteen."

 

[Ryan_m_b]

"The Golden Age of science fiction is fourteen."

Lol, I think as I've aged I lean more towards hard SF with the occasional spattering of soft. "Big ships go bang with lasers through hyperspace" gets tiresome after puberty.

 

[SHISHKABOB]

Lol, I think as I've aged I lean more towards hard SF with the occasional spattering of soft. "Big ships go bang with lasers through hyperspace" gets tiresome after puberty.

While I do agree that sci fi with big space ships with big lasers and explosions is often kind of shallow, I do know one example that contradicts it. It's a show called Legend of the Galactic Heroes, and it's got quite a few big space battles between huge fleets of space ships that fly around like boats, etc.

but the rest of the show is waaaaaay deeper than that. It's definitely not meant for kids.

The space part of it is honestly used to make it more exciting and interesting. It's pretty much a "war in peace in space". In terms of number of characters and breadth of plot and setting.

 

[Ryan_m_b]

While I do agree that sci fi with big space ships with big lasers and explosions is often kind of shallow, I do know one example that contradicts it. It's a show called Legend of the Galactic Heroes, and it's got quite a few big space battles between huge fleets of space ships that fly around like boats, etc.

but the rest of the show is waaaaaay deeper than that. It's definitely not meant for kids.

The space part of it is honestly used to make it more exciting and interesting. It's pretty much a "war in peace in space". In terms of number of characters and breadth of plot and setting.

I might check it out don't get me wrong, sometimes all I want to do is read something so soft you could spread it on your toast in the morning. But generally I'm more of a 4/4.5 on http://tvtropes.org/pmwiki/pmwiki.php/Main/MohsScaleOfScienceFictionHardness

 

[Borek]

Even more off topic:

Lastly IIRC from the latest batch of Star Wars films George Lucas made a bizarre government for (I forget the name of the planet where the first one is based) wherein they have an elected Queen who sits out two terms maximum and abides by a constitution...

Electing a King? Not a problem:

http://en.wikipedia.org/wiki/Royal_elections_in_Poland

 

[Ryan_m_b]

Even more off topic:



Electing a King? Not a problem:

http://en.wikipedia.org/wiki/Royal_elections_in_Poland

Ah interesting. Though in keeping with the weirdness of lucas I'm guessing none of these royals had to abide by a two term constitution

 

[SHISHKABOB]

I might check it out don't get me wrong, sometimes all I want to do is read something so soft you could spread it on your toast in the morning. But generally I'm more of a 4/4.5 on http://tvtropes.org/pmwiki/pmwiki.php/Main/MohsScaleOfScienceFictionHardness

I don't have a lot of experience with the mohs scale, but after reading through the different levels I'd toss LoGH into like... somewhere around 2 or 3. The sci-fi is pretty darn soft. They don't ever bother explaining how the FTL travel works, it's just "yeah they get around". It's also not... terribly consistent, I suppose.

But that's just the science fiction aspect of it. What makes it a great show is the characters and the plot. Plenty of politics, discussions on stuff like authoritarianism vs. democracy, the role of the military in a democracy, the merits of authoritarianism/democracy. etc. To be quite honest, the science fiction is almost there just to "spice things up" and make it more interesting. It's just a show about two nations going to war, but transplanted into space.

I think my favorite theme of the show is summed up in a quote by one of the characters: "There are few wars between good and evil; most are between one good and another good."

I could probably count the "truly evil" characters on one hand, maybe two. They're all spread throughout the whole setting. In fact, one of the biggest jackasses of the show is one of the most powerful men in the democratic faction.

 

[GTOM]

Thank you for your suggestions. :)

Although i have to say i didnt really liked LoGH, but there were good parts I admit. :)
What i despised is Yang Wenlii... the empire attacks a patrol with an another patrol... send there our whole fleet yeah why not... Next time they attack with a BIG fleet, oh it is bound to be a decoy, the real attack, comes from the other direction.
Then the politicians : but Phezzan will not let it... and what did they think, what can a single planet do against a fleet of an empire, if the empire's leader don't respect the status quo?
But again i admit there were good thoughts in it. :)

New BSG i liked it at first :), but at the end of the third season... i hoped the Cylons will win...

On rocketpunk manifesto, we thought about, what can be the closest relative to the pop sci space fighter. (well, maybe its only me, i more like swarms of ships, than big battleships just keep shooting each other)
I think we worked out something : it would be a several hundred tons ship (mostly remote controlled), with nuclear thermo drives, most of its mass is the propellant (monatomic hydrogen). Capable to perform some tenth G acceleration in order to change its orbit, ascend to high orbit from low orbit, then return, or reverse.
Armed with laser jammers, cannons for self defence, (short range) missiles for attack.

It would be the descandent of present day littoral patrol and combat boats, mostly used to maintain peace and order (that is an important task in modern warfare, in Iraq, Afganistan)
In actual combat, unlike a simple missile, it is reusable (yes they will require the support fire of either bigger ships, or planetary defence to keep the mortality rate down) and more adapt in operating in orbital environment, where are cover, background clutter, possibly lots of debris, anti missile mines, satellites, aerial and ground targets.
(In a simple deep space combat, simple missiles are enough, and require less resources. )
The mothership would be the descandant of torpedo boat tenders, it is task is to regroup surface troops and orbital ships between colonies, invade, pacify, secure, aid them.
It can also serve a mobile base for your fleet.

Does that sound a bit plausible?

 

[ImaLooser]

I think space ships are old school. I don't see how you can take one to Jupiter, much less to another star.

I've got ideas but they are speculative so I ain't saying nuttin.

 

[GTOM]

I guess you watched StarGate. :) If you have other ideas, you can share me privately.

 

[Ryan_m_b]

Does that sound a bit plausible?

Reading through all of that gives me a distinct reminder of reading accounts of how tacticians circa 1900 thought speculative air battles would be. I'm agreeing with ImaLooser on this point:

I think space ships are old school.

The fundamental concept that space craft can be analogised to naval ships automatically handicaps the discussion. The differences between space and the ocean are significant in spite of superficial similarity.

 

[GTOM]

"The fundamental concept that spacecraft can be analogised to naval ships "

I know there are several differences, but i find it hard to ignore certain analogies...
The word battlecruiser sounds better than big size rocket with patrol/attack duties. Frigate sounds better then middle sized patrol spacecraft .
Travel lengths, lots of people sharing the hull of a single vehicle, that travels through a hostile environment, also brings up theese analogies.

Should someone come up with entirely new terms?

 

[Ryan_m_b]

The problem is the imposition of similarities based on assumptions. For example: the idea that you would have "patrol ships" because patrolling would be a necessary job of military space craft. To have this discussion properly you have to first determine what situations military spacecraft would be necessary/desirable for as well as determining what technology will be available for them.

 

[GTOM]

Ok.

Well it is easier to answer certain questions in an SF operatic setting with the good old magical hyperspace jump drive.

But at first a not so far future scenario i have the following thoughts :

There would be space stations producing stuff requires zero-G, act as luxury hotels for rich people. There would be lunar colonies, mining HE-3 and other things. There would be much cheaper methods to reach orbit than today : induction catapults, laser assisted rockets, skyhooks lifted up by magsailed ships. There can be also orbital habitats for lunar executives who has to be relatively close, but don't want too much exposure to low-G.
There would be near Earth asteroid mines, orbital depots.

Earth still don't has a monolithic government, corporations also have the power of small (or not so small...) nations, there might be corporate warfare, terrorism and organised crime can be also significant.

An orbital fast attack craft (fighter) would have the following jobs : monitor surface, possibly drop kinetic bombs, force suspicious ships (they might smuggle guns or drugs, spies, crime lords, terrorists, or maybe they try to ram you in a 9/11 style) to change their course to your port, abandon resistance. Or maybe destroy them if necessary.
(Well some of theese things supposes that there won't be really strong long range lasers, and kinetics still have an important role.)
A corvette (attack/transport craft) could carry more kinetic bombs, or transport police, military commandos, detainees.

If things get nasty, you might need fast Earth-to-Moon ships, that can reinforce the local ones (frigates, destroyers). (The first two kind of rockets act between LEO and GEO or possibly they land on the surface.)
If things get really bad, you might even need the mothership, that would be a mobile spinning station, that can house lots of fighters, corvettes, marines, supplies.Later if we could reach even farer, there can be big battleships and destroyers meant to take over particulary valuable asteroid mines, battlecruisers to attack or protect convoys.

 

[GTOM]

The bigger they are, the better they are. Assuming for a moment that we are just talking about something like a telescope (that looks for visual and infrared) if the ship has interferometers along it's length then it is in essence a giant telescope (there's an equation for figuring out the resolution of a telescope based on its diameter but I don't remember it). If the ship needs better resolution then what it should do is spread out a bunch of probes in an ever expanding sphere so that they act like one giant telescope rather than loads of tiny ones.

If we're not just talking about telescopes though IIRC a larger ship benefits from being able to house neutrino detectors which would make any ship using a fission or fusion reactor/drive stand out like a flare in a dark field.

Exactly.

Well, i would like to have another question about it.
A Kepler and Hubble can already see many many things, explore the shadows of very distant planets etc. I guess the military could have launched something like that to watch Earth.

Yet as far as i know, that doesn't turned old fashioned recon obsolate...

Why is it? It looked like to me, you could scale up resolution with a huge telescope to see everything you want to see on a certain area of Earth.

 

[Ryan_m_b]

Hubble can't see anything on Earth's surface, it would be a huge blur. Regardless though...is your question serious? The reason why satellites haven't replaces HUMINT is that they have severe limitations like not being able to see in buildings or overhear/steal/gain through talking intelligence locked in people's heads or other media. As far as I'm aware there's no one not on Earth worth getting intelligence out of :rollseyes: Also if we do propose space colonisation that doesn't change much. HUMINT operators will have to use whatever travel is available to get to their destination settlement.

One final but oft repeated point: space is big. There is no analogy for a space patrol.

 

[GTOM]

Ok i wasnt punctual enough : when i meant recon, i thought about locating vehicles or machinegun nests, or troops for example, not people inside a buliding, not secret intelligence. And there are still recon vehicles and drones, not just satellites for the former purpose, or am i wrong?

Well unless we introduce certain operatic things, then ok, you don't use a ship just to detect something in space, but if you want to something with a situation, and local forces (if we talk about a situation on the ground) arent enough, then it is good to have a patrol ship IMHO.
(And it only has to patrol between areas of interest and act if necessary, otherwise its simple presence is threatening to bad guys. At first level i think about an operational area of Earth's orbit or Earth to Moon.)

 

[cephron]

If we're not just talking about telescopes though IIRC a larger ship benefits from being able to house neutrino detectors which would make any ship using a fission or fusion reactor/drive stand out like a flare in a dark field.

Fascinating! I'll have to read up on this. Would you basically need multiple neutrino detectors arranged at distance from each other, in order to pick up relative differences and calculate the position of the source? Or can a single detector obtain the direction of the source?

*goes off to wikipedia...*

 

[ImaLooser]

The thing about space combat is that it is very difficult to hide anything. Even with today's technology tiny things can be tracked.

My guess is that any kind of space combat would be so fast and secretive that it would all be done by computers. There would be no human involvement at all. You would be flying along and either suddenly cease to exist or get a computer message that you just won.

Any ordinary spaceship would have a tiny crew that was bored as could be, just waiting for something to repair. Any sort of warship would be completely unmanned.

 

[Ryan_m_b]

(And it only has to patrol between areas of interest and act if necessary, otherwise its simple presence is threatening to bad guys. At first level i think about an operational area of Earth's orbit or Earth to Moon.)

Space is big. Patrolling between areas of interest is at best going to take days (Earth-Moon system) and at worse years. There is no point sending a craft on a continual loop between interesting locations on the off chance that during its months/year long round trip something might happen at just the right moment for it to be around to help. This is why the idea of patrolling makes no sense.

Similarly if it takes years to get anywhere then by the time you get there the thing to came for is likely to be over. If military presence was deemed to be a necessity then it's likely to be a permanent, on site feature rather than something that is moved around like today.

Fascinating! I'll have to read up on this. Would you basically need multiple neutrino detectors arranged at distance from each other, in order to pick up relative differences and calculate the position of the source? Or can a single detector obtain the direction of the source?

*goes off to wikipedia...*

I'm not sure, I'm guessing several.

The thing about space combat is that it is very difficult to hide anything. Even with today's technology tiny things can be tracked.

Quite, it's even easier when the object in question is several hundred degrees hotter than its surroundings http://www.projectrho.com/public_html/rocket/spacewardetect.php#id--There_Ain't_No_Stealth_In_Space

My guess is that any kind of space combat would be so fast and secretive that it would all be done by computers. There would be no human involvement at all. You would be flying along and either suddenly cease to exist or get a computer message that you just won.

Any ordinary spaceship would have a tiny crew that was bored as could be, just waiting for something to repair. Any sort of warship would be completely unmanned.

It really depends on what we mean by space combat. Curiously we don't generalise for anything else, why space?

 

[GTOM]

What about orbital patrol? The ranges are smaller.

I think about the descandants of this : http://en.wikipedia.org/wiki/Boeing_X-37

(Ok, than no frigates just destroyers with Earth to Moon range...)

I would be still curious : if we can already see distant planets, why USA sends drones to unfriendly countries, where they are shot down and hacked up? Why can't they solve recon with a big orbital scope? I don't think a RQ-170 Sentinel could enter into buildings, overhear conversations...
Is it because the distortion of the atmosphere, or what?Otherwise I can agree that short range craft can be remote controlled, but i sure wouldn't trust decision making to compus (at least... ). It would be too much temptation to politicans and military leaders.
A drone operator can still feel remorse, guilt.

 

[Ryan_m_b]

What about orbital patrol? The ranges are smaller.

You can drop patrol there and just say orbit unless you want a craft tat burns through all its few a short time after deployment. Otherwise sure.

I think about the descandants of this : http://en.wikipedia.org/wiki/Boeing_X-37

I doubt like this. I'm thinking more along the lines of the international space station with more propulsion and weapons. Not a space plane. You can't dog fight in space and there isn't a role that I can see for a fighter type craft between larger craft and smaller missiles.

I would be still curious : if we can already see distant planets, why USA sends drones to unfriendly countries

Firstly our detection of exoplanets is not by seeing them directly, but by observing the effect they have on their sun. Secondly whilst we can see planets in this system there are things that telescopes can't do that we use probes for. Thirdly what we're talking about in this thread is the detection of spacecraft which would not be done by visual means of the craft itself but by thermal means of it and its exhaust. Lastly satellites in Earth orbit have only a tiny amount of the the surface they can see at anyone time in their orbit (presuming no cloud cover and its day). No nation has so many satellites that they can see any point on Earth at any time so drones are used (amongst other reasons).

 

[GTOM]

"I doubt like this. I'm thinking more along the lines of the international space station with more propulsion and weapons. Not a space plane. You can't dog fight in space and there isn't a role that I can see for a fighter type craft between larger craft and smaller missiles."

I think that depends on exactly what you want to achieve. (And what kind of engine developments can we achieve.)

Ok if you can barely have enough delta-V to reach a certain target and only want to destroy that, yes you use a missile.

If you want to reach multiple targets, you can provide enough delta-V, and maybe not destroy just capture some of them, i see a role for smaller planes.

For example you might want protect your own satellites meant to watch a country, attack the satellites (and anti satellite missile sites) of that country, that means all of them will fly above that country.
Then you can position a squadron of small ones to a low orbit, where they might protect an own satellite at first, bomb a missile site next, then modify orbit to attack an enemy satellite. (They might use the upper stratosphere to modify their vector?)
During this, you might want to keep your precious station on a high orbit, possibly GEO above your country. (if they have the technology to attack it... yes it can defend itself much better than the small ones, but you can afford to lose some of the small ones, while you don't want to endanger a big station)

Or you want to capture a rocket of a crime lord, before it could reach a safe haven.
A missile can't capture a ship, a plane can fire warning shots to it, and only destroy it if absolutely necessary. Ok you might fire a missile and blow it up, if they modify their course, but you sacrifice the missile.
Assuming that fuel will be cheap enough, and there will be cheap methods to get it to orbit (asteroid mine, induction catapult, space elevator from Moon) it is better to sacrifice fuel then missiles, and care about versatility and reusability.
(Well intercontinental ballistic missiles exists for long, there are also high-precision missiles, but attack vehicles are still needed. )

I have a Mohs scale 5 situation in mind.

 

[Ryan_m_b]

You're really underestimating how much all that manoeuvring is going to cost in terms of fuel and energy and therefore mass and therefore thrust. Orbital speed it a hell of a lot faster than anything in atmosphere. You can't just shed that and speed off in other directions. On top of that you should brush up on the basics of orbital mechanics, you can't have a squadron of planes hovering under the orbit of a satellite, at least not without constant thrust. On top of that none of the tasks you mention would be best suited to planes over weaponised satellites.

Regarding capturing a craft that's pretty much impossible. It requires you carefully match velocity and gently dock. Not going to be possible if the other craft doesn't want you too, all they have to do is spin their craft along its axis and you're screwed.

I'm sorry but this isn't moh-5, more like 2. I think you're basing too much of this on science fiction and not science.

This thread has gone on long enough with no development. I suggest we take a break until anyone has something definitive to discuss I.e some actual science to speculate on or some fiction to talk about.

 

[GTOM]

Ok, weaponised reloadable satellites.
I hope this is a development, if not, than sorry, do what you have to do.


Another things : in space there are pretty much radiation. Earth is protected by its magnetic field from the worst things. Could this be a viable method to protect spaceships (colonies) instead of thicker hulls?

 

[Ryan_m_b]

There is research along those lines
http://physicsworld.com/cws/article/news/2008/nov/06/magnetic-shield-could-protect- spacecraft

 

[GTOM]

Thank you.


A bit more about protection and sci-fi : i found a link in this forum, in an experiment they used magnetic fields and lasers to keep particles at one place. When they released them, they drew away that much energy, that they called their state beyond absolute zero...
Is there any chance that this super entropy-less state could be used to create some supersolid armor? (well a bit like to the concept of energy shield)

Second, about induction catapults, mass drivers, coilguns.
What could be the theoretical limit of acceleration, that a simple solid object could withstand without ripped to plasma dust?

So for example, if one would like to take out a meteor, and boost a projectile to 10km/s in order to do it, what could be the minimum length of the coilgun?
(Assuming, with some next generation technology, they can solve power supply, engineering, recoil etc)

 

[Ryan_m_b]

Here is the PF discussion on the topic https://www.physicsforums.com/showthread.php?t=662268.

Re acceleration if it is uniform across the object then the answer is infinite. If not it's down to the material properties of whatever it is made out of. Re length it depends on how fast you're accelerating. Ask in one of the physics forums if you want to learn how to work it out.

 

[GTOM]

Ok, thank you.

(And again, sorry for our previous misunderstainding. :( I should have made it clear that I imagined the orbital craft to operate in a wider orbital belt, so it could observe and attack more, gradually modificating course during turn around the planet, and by capture, i meant, force to surrender by lethal threat. )