What kind of military spacecraft can we create with current technology?

[Diche Bach]

"Myoparo!" A new word I never heard of!

[kerbiloid]

4 hours ago, Diche Bach said:

"Myoparo!" A new word I never heard of!

The most popular Roman-age pirate ship. Like a gunboat, but without engines. Made of skins and wood.

[Nibb31]

15 hours ago, kerbiloid said:

The first Interstellar Battleship really engineered (just still not built) by humanity.

A quick sketch on a paper napkin is not engineering.

15 hours ago, kerbiloid said:

A two-staged thermonuclear booster accelerates a 450 t kinetic warhead up to 0.1 c speed, aiming to a potentially habitable planet system, as close to the target planet as it's possible.

At 0.1c, it's actually more likely that your spacecraft gets disintegrated by hitting a micro-meteorite or a particle of interstellar dust long before it reaches its target.

[kerbiloid]

26 minutes ago, Nibb31 said:

At 0.1c, it's actually more likely that your spacecraft gets disintegrated by hitting a micro-meteorite or a particle of interstellar dust long before it reaches its target.

They put a beryllium screen against meteorites (you can see it on the top).
Btw also this screen would protect this kinetic warhead peaceful scientific probe against neutrons of ET ABM nukes.

26 minutes ago, Nibb31 said:

A quick sketch on a paper napkin is not engineering.

As any project which could be sampled here. Except an orbital station with 23mm gun.

Edited September 19, 2016 by kerbiloid

[tater]

 

(HST, but looks pretty much the same as KH 11/12)

That's pretty much it, as there is no reason to build anything that looks anywhere except Earth from a military standpoint.

[DDE]

1 hour ago, tater said:

 

(HST, but looks pretty much the same as KH 11/12)

That's pretty much it, as there is no reason to build anything that looks anywhere except Earth from a military standpoint.

You forgot these two puppies:
 

Spoiler

 

 

 

 

[peadar1987]

19 hours ago, kerbiloid said:

The first Interstellar Battleship really engineered (just still not built) by humanity.

...

Once a sentient race achieves this technical level, it starts sending kinetic warheads peaceful scientific probes to any potentially habitated planet in 100 l.y. around. With a lethal accuracy.

Except if you're going to hit something, ever, it's overwhelmingly likely you're going to hit a star, or a gas giant.

Take out solar system for example. The sun is 110 earth radii. Jupiter is 11, Saturn is 9, Uranus and Neptune are about 4.

That means the sun is a target with an area 12,000 times that of earth. Jupiter a further 120, Saturn 80, and so on.

If you launched 10,000 warheads, you'd still only have a 43% chance of hitting anything other than the sun. And that's neglecting any gravitational effects. The sun is a big gravitational mass, and will curve trajectories towards it, even at 0.1c, giving it an even larger effective radius as a target.

Spamming the heavens randomly with kinetic warheads is hardly an effective way of achieving anything at all.

[Diche Bach]

2 hours ago, peadar1987 said:

Except if you're going to hit something, ever, it's overwhelmingly likely you're going to hit a star, or a gas giant.

Take out solar system for example. The sun is 110 earth radii. Jupiter is 11, Saturn is 9, Uranus and Neptune are about 4.

That means the sun is a target with an area 12,000 times that of earth. Jupiter a further 120, Saturn 80, and so on.

If you launched 10,000 warheads, you'd still only have a 43% chance of hitting anything other than the sun. And that's neglecting any gravitational effects. The sun is a big gravitational mass, and will curve trajectories towards it, even at 0.1c, giving it an even larger effective radius as a target.

Spamming the heavens randomly with kinetic warheads is hardly an effective way of achieving anything at all.

Even more support for my space-pirate capsul . . . erm "Space Myoparo"

[kerbiloid]

3 hours ago, peadar1987 said:

Take out solar system for example. The sun is 110 earth radii. Jupiter is 11, Saturn is 9, Uranus and Neptune are about 4.

That means the sun is a target with an area 12,000 times that of earth. Jupiter a further 120, Saturn 80, and so on.

That's true if just launch the penetrator probe towards the star system at all.
Easy to calculate that launching such probe towards the Solar System we would get mostly photos of black abyss of space.
Barnard Star - the Daedalus main target - had been chosen due to its two planets (as we now know, just phantom ones).
So, to get reasonable results from the over-expensive craft you should launch it as close to the planet of interest as your accuracy allows. The closer - the better. Like New Horizons, exactly close to Pluto and Kharon.

So, you would use not Solar system total area, but Earth passing-by area.

[Sereneti]

high speed, high altitude Bomber.

Orbital-laser.

Anti-Satelite-weapons.

Kessler-"Bombs" (a lot of small steel/keramik balls)

a War in space, will took out the whole humankind possibiliti to go into space. Kessler - Syndrome....

Edited September 19, 2016 by Sereneti

[peadar1987]

1 hour ago, kerbiloid said:

That's true if just launch the penetrator probe towards the star system at all.
Easy to calculate that launching such probe towards the Solar System we would get mostly photos of black abyss of space.
Barnard Star - the Daedalus main target - had been chosen due to its two planets (as we now know, just phantom ones).
So, to get reasonable results from the over-expensive craft you should launch it as close to the planet of interest as your accuracy allows. The closer - the better. Like New Horizons, exactly close to Pluto and Kharon.

So, you would use not Solar system total area, but Earth passing-by area.

Yes, but you were saying that if you missed your initial target, you would eventually hit something. I was just pointing out that that something would most likely be a star, which wouldn't even burp at a 50 gigatonne impact.

At 0.1C, it would be pretty easy to destroy as well. A 20km/s asteroid is a planet-killer. A 30,000km/s relativistic kill vehicle would turn into a rapidly-expanding cloud of plasma if you fired a few ball bearings at it. Beryllium shield or no. And it would be very obvious if one was coming for you.

[Kerbinchaser]

A probe with a Thermo nuclear vacuum missile. It would have to withstand heat though. 

[Kerbart]

I'm surprised that only a few have mentioned the #1 application for military space vehicles: reconnaissance. And everyone who's space capable is already doing a ton of that.

Aviation started the same way. Excellent vision, not challenged by surface weapons. That quickly changed in WW1 though

When we have a serious armed conflict between two space-faring nations we'll learn what the arms race is space is really going to look like. Let's hope we'll have to do with theoretical models for a long time.

[kerbiloid]

56 minutes ago, peadar1987 said:

Yes, but you were saying that if you missed your initial target, you would eventually hit something. I was just pointing out that that something would most likely be a star, which wouldn't even burp at a 50 gigatonne impact.

OK, this is true. Also is true that any IRL missile and even every anti-aicraft shell necessary contains a self-destruction mechanism which destroys it after a miss - though it almost always will fall somewhere in unpopulated area with even less chances to fall on somebody than Earth:Sun ratio..

I was just amused when realized that Daedalus is 50 Gt shell just to be thrown at hazard without any attempt to prevent its possible collision with somebody's planet - just because it's "scientific", not "military".

Edited September 19, 2016 by kerbiloid

[Emperor of the Titan Squid]

 

14 hours ago, DDE said:

You forgot these two puppies:
 

  Hide contents

 

 

 

 

Is that polyus, skif, kaskade, or something else entirely? 

Edited September 19, 2016 by Emperor of the Titan Squid

[Reactordrone]

2 hours ago, Emperor of the Titan Squid said:

 

Is that polyus, skif, kaskade, or something else entirely? 

The first two pictures are an Almaz military space station(unmanned radar recon version) and the cannon that the manned stations were armed with.

Edited September 20, 2016 by Reactordrone

[DDE]

8 hours ago, Emperor of the Titan Squid said:

Is that polyus, skif, kaskade, or something else entirely? 

What the Cyberman said.

The second is an IS kamikaze sat, along with DoD's conceptual depiction of a non-kinetic ASAT.

[peadar1987]

18 hours ago, kerbiloid said:

OK, this is true. Also is true that any IRL missile and even every anti-aicraft shell necessary contains a self-destruction mechanism which destroys it after a miss - though it almost always will fall somewhere in unpopulated area with even less chances to fall on somebody than Earth:Sun ratio..

I was just amused when realized that Daedalus is 50 Gt shell just to be thrown at hazard without any attempt to prevent its possible collision with somebody's planet - just because it's "scientific", not "military".

Haha, okay. Yeah that's not a problem humanity have had before. We never risked destroying the New World by sailing a galleon at it too quickly!

[SomeGuy123]

Ok, let's assume the aliens don't have force fields or antigravity or anything else that known science doesn't say is possible.

So what do they have? Well, they have interstellar flight.  And they must have used anti-matter pion propulsion to do it.  (or maybe a black hole engine).

So there's actually one big advantage we'd have on Earth.  Warning time.  Their ship would take decades to decelerate, and leave a flare of gamma rays as it does so.  Both engine types emit much of their exhaust energy in the form of gamma rays.

Ok, what else do the aliens have?  They probably have molecular nanotechnology, and they probably can copy themselves very rapidly given the needed resources.  But their starship itself is probably very small and light at the end of an interstellar voyage, having burned off most of it's mass during the trip as propellant and expended stages.

If that's true - again, I'm assuming plausible limitations based on current scientific knowledge - then it's not hopeless.

Basically you have to assume that the alien ship is higher quality than anything we can make on earth.  It can probably reconfigure itself and repair damage very rapidly.  So you need at least 100 : 1 odds.  If the alien ship weighs 1000 tons of payload*, you need to send 100 kilotons of warships to intercept it.  And you have to reach it before it can dock with an oort cloud object and grow rapidly into an unstoppable fleet.

What would the warships be?  Orion nuclear pulse battleships, armed with lasers and nuclear howitzer rounds.  Obviously.  There's no stealth in space so you just have to get into range.  Realistically you'd probably want to try to ram the alien ship.  You've got to assume that long before you get into range, the alien ship would probably reconfigure itself into a gamma ray laser with incredible range or something.  Maybe 100 : 1 odds isn't enough...

* you calculate the payload mass of the alien ship with spectroscopy to analyze their engine flare, then you look at how fast it is decelerating.

It certainly sounds like an interesting scenario.  

Edited September 20, 2016 by SomeGuy123

[Diche Bach]

Aren't "wormhole" generators just about as plausible as "pion" propulsion (whatever that is)?

Are the tracking and targeting parameters even realistic? I mean: incoming ship decelerating from interstellar flight and "Orion nuclear pulse battleship" attempting to intercept. Could either of them even track one another (with existing tech) much less hit one another?

Obviously they could establish communications link or rendezvous, but that is not the same thing as hitting a moving target, eh?

Who cares how big your cannonball or arrow (missile) are if every shot you fire misses by hundreds of kilometers!?

And then we come to electronic warfare. You said "no stealth" in space, but  . . . really?

ADDIT: also, if the alien ship is using "antimatter" power source for its propulsion, then why assume it would be "lighter" after its long journey!? or that it would involve "stages" at all? no?

I'm guessing: if you have the tech to do antimatter power, then you probably don't even need to be "near" the target planet. Just send a killer drone ship within range of the target system and generate an antimatter cannonball on an impact orbit: might take months or years but end result enemy defeated, their entire planet vaporized. They might not even know what hit them.

Edited September 20, 2016 by Diche Bach

[SomeGuy123]

15 minutes ago, Diche Bach said:

Aren't "wormhole" generators just about as plausible as "pion" propulsion (whatever that is)?

Are the tracking and targeting parameters even realistic? I mean: incoming ship decelerating from interstellar flight and "Orion nuclear pulse battleship" attempting to intercept. Could either of them even track one another (with existing tech) much less hit one another?

Obviously they could establish communications link or rendezvous, but that is not the same thing as hitting a moving target, eh?

Who cares how big your cannonball or arrow (missile) are if every shot you fire misses by hundreds of kilometers!?

And then we come to electronic warfare. You said "no stealth" in space, but  . . . really?

ADDIT: also, if the alien ship is using "antimatter" power source for its propulsion, then why assume it would be "lighter" after its long journey!? or that it would involve "stages" at all? no?

I'm guessing: if you have the tech to do antimatter power, then you probably don't even need to be "near" the target planet. Just send a killer drone ship within range of the target system and generate an antimatter cannonball on an impact orbit: might take months or years but end result enemy defeated, their entire planet vaporized. They might not even know what hit them.

No.  Wormhole generators are not known to current science.  If you had typed pion propulsion into wikipedia, you'd get this : https://en.wikipedia.org/wiki/Antimatter_rocket

TLDR, if you combine antiprotons and protons you get charged particles called pions.  You can redirect them out the back with magnetic fields.  People have worked out how strong the magnets would need to be and what geometry they would be in.  All feasible with current science.  The missing piece is mass production of antimatter but there are plausible methods to do that.

A ship decelerating from interstellar flight headed for an Oort cloud object would be interceptable as it would be going far slower at the end of it's journey.

There isn't stealth in space.  All weapons use thrusters to course correct during flight, casablanca howitzer rounds would have onboard control and thrusters.   

There's no reason to assume that the aliens could "hack" or "fool" human systems they have never encountered, especially since the hard laws of physics means their ship must emit a signature flare that is incredibly bright in order to have the ISP for interstellar flight.

Yes, if the aliens plan to ram the earth we are screwed.  I'm assuming they recognize the earth, as a naturally occurring biosphere, is in itself valuable and they intend to seize it without destroying it's value.  Their plan, if they got that far, would be to dock with oort cloud objects.  Self replicating factories would rapidly expand, and in a few years they'd have an unstoppable fleet of thousands or millions of warships.  They'd be able to conquer earth by sniping all the military forces with laser fire from orbit and then sending ground robots to the surface to root out any remaining resistance.  As they would have self replication and artificial intelligence, casualties would be meaningless.

 

[KSK]

24 minutes ago, SomeGuy123 said:

Ok, let's assume the aliens don't have force fields or antigravity or anything else that known science doesn't say is possible.

Sounds good.

24 minutes ago, SomeGuy123 said:

So what do they have? Well, they have interstellar flight.  And they must have used anti-matter pion propulsion to do it.  (or maybe a black hole engine).

Ohhh-kay. Black hole engines sound totally legit and within the realms of scientific possibility. Personally, I'd go for an Infinite Improbability Drive but whatever.

26 minutes ago, SomeGuy123 said:

They probably have molecular nanotechnology,

 

27 minutes ago, SomeGuy123 said:

It can probably reconfigure itself and repair damage very rapidly.

Not much point having molecular nanotech if it can't tbh.

27 minutes ago, SomeGuy123 said:

So you need at least 100 : 1 odds.

We do?

28 minutes ago, SomeGuy123 said:

Orion nuclear pulse battleships, armed with lasers and nuclear howitzer rounds.  Obviously.

Obviously. Although any spare antimatter from that pion drive is going to make a real mess of an Orion. If the aliens are packing enough antimatter for interstellar flight, they've probably got enough left over to use as munitions. Hey - I can play the 'probably' game too!

35 minutes ago, SomeGuy123 said:

It certainly sounds like an interesting scenario.  

It sure did make for a great sci-fi novel.

[SomeGuy123]

12 minutes ago, KSK said:

Ohhh-kay. Black hole engines sound totally legit and within the realms of scientific possibility. Personally, I'd go for an Infinite Improbability Drive but whatever.

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

Unlike wormholes, black hole engines violate no known principles of physics.  It is true that science is a bit uncertain about certain critical facts* as we've never seen a black hole, so using one as an engine may not be possible - but from current knowledge it is possible.  All it is is E=mc^2 in the opposite direction.  The black hole is acting like a perfect converter of matter to energy, and then your ship just has to reflect the released gamma rays (doable, using methods demonstrated on earth) backwards.  The black hole must be able to hold an electric charge so that it can be kept attached to your ship's engine bell via magnetic or electric fields.

I find is reasonable plausibly that you can do this.  What isn't plausible is wormholes because they require negative energy, which current science has never observed anywhere.  We've observed black holes and theorize that a small artificial one would do what we want.

Those theories may be wrong - but maybe fusion drives are also impossible.  Maybe AI's impossible.  And molecular nanotech.  Essentially you can assume that anything that doesn't exist right now this very week is impossible due to undiscovered laws of the universe.  I would call that "motivated cognition" - you disagree with me on plausibility and thus want everything I want to be impossible.

* the 2 major critical facts are : can a black hole hold an electric charge, and how easy is it to feed a tiny black hole via a particle beam?

TLDR, a black hole engine is : 

1.  Ram together metal rods at close to the speed of light to form a black hole using an apparatus that spans across a solar system

2. Feed the resulting black hole from a particle beam so it remains the same size.  Size determines power output, it would emit gigawatts to petawatts in the form of gamma rays so it burns matter constantly.  Feed the hole a diet rich in either positively or negatively charged particles so that it retains a charge, even if said charge is actually matter clumped at the event horizon and the hole itself is neutral.

3.  Using magnets and electric fields, install it in a starship, which is a gigantic parabolic dish of gamma ray reflective lensing material that bend the gamma rays to all travel backwards.  

4.  Ride that baby to wherever you want.  You can even collect interstellar hydrogen to feed the black hole, unlike a fusion ramscoop you would actually gain velocity doing this.  You have an ISP of something like 5C...and an acceleration somewhere between a few centimeters per second^2 to m/s^2.  (limit is how well you can reject waste heat from the gamma ray reflector and how much of the gamma rays are absorbed)

An infinite improbability drive is a purely fictional contrivance and it has no mechanism described whatsoever.  I'm sure you can see the difference now between the 2.

Edited September 20, 2016 by SomeGuy123

[KSK]

Disagree. From the Wikipedia article you quote:

"Alexander Bolonkin and Louis Crane, Shawn Westmoreland offered and published a paper and book [1 -3] investigating the feasibility of this idea. Their conclusion was that it was on the edge of possibility, but that quantum gravity effects that are presently unknown will either make it easier, or make it impossible."

So we don't actually know whether it's even theoretically possible. 

But anyway, even assuming all of your alien futuretech works, the idea that we're going to be fighting it using Orion battleships is absurd. In fact the idea that we're going to be fighting it is absurd. From Wikipedia.

"The Oort cloud (/ˈɔːrt/ or /ˈʊərt/,^[1] named after the Dutch astronomer Jan Oort), sometimes called the Öpik–Oort cloud,^[2] is a theoretical cloud of predominantly icy planetesimals believed to surround the Sun to as far as somewhere between 50,000 and 200,000 AU (0.8 and 3.2 ly)"

0.1c appears to be a good cruising speed for an Orion ship. Assuming that acceleration and deceleration times are negligible, it's going to take about thirty years to get out to your alien starship, even assuming we had a convenient Orion battleship parked in orbit and ready to go. That's going to take a chunk out of any lead time we get by being able to track the aliens as they decelerate towards the Oort cloud. But, even assuming we manage to overcome that and get an Orion there in time, before the aliens manage to magic - excuse me, nanotech up their unstoppable fleet, that Orion is going up against a starship propelled by ridiculously intense gamma radiation.

Aliens spot Orion coming, Aliens turn spaceship around, Aliens fire up their gamma ray drive. Bye, bye Orion. Or bye bye Orion as an effective fighting vessel anyway.

Edited September 20, 2016 by KSK

[Diche Bach]

I thought wormholes were a pretty good theory though!? No?

Shucks.

ADDIT: this thread needs a theme song

 

Edited September 21, 2016 by Diche Bach
theme song