Orbital weapons

[p1t1o]

21 minutes ago, YNM said:

Your silos aren't really photograph-proof. Satellites however, are almost always photograph-proof - once up in orbit no one can really see what's up there in detail.

But a silo can withstand all but a direct hit from a high-yield nuclear strike, a satellite can be taken out by a ball bearing. Or at the very least, much much less than that required to knock out a silo.

There are political advantages to having your weapons easily observed as well, and disadvantages to stealthy less-readily-identifyable ones.

I dont imagine that the identification of battlestations would be that much of a difficulty for a determined adversary, there are specific things about them which make them stand out - size, thermal signiture, orbital parameters etc. It is probable that they will be tracked by significant players from the moment thy are launched.

[Hypercosmic]

38 minutes ago, p1t1o said:

That is...quite far...I wonder what sort of effect you will get spreading 1GW across the sort of spot-size you can expect at 100,000km.

I cant see the picture from here unfortunately, where is this laser from?

Using this calculator:

http://www.5596.org/cgi-bin/laser.php

1GW at 50,000km vaporises 0.5mm per second of aluminium. Its not great.

At 1000km though, it vaporises 6.2metres of aluminium per second.

However, this laser requires a 10metre lens and will generate megawatts of waste heat. Along with a Gigawatt powerstation...

Further to that, the simple calculation ignores things like material blow-off which will significantly impact penetration.

These capabilities dont come cheap, which is the problem. Whilst "technically" "feasible", as weapons they may be worse than useless.

This laser draws 1.00 GW, the output is 416 MW (yes, absurd efficiency!) at wavelength of 77 nm. Intensity at 1 km is 552 PW/m², and at 100,000 km is 55.2 MW/m². I assure you, this is enough for disabling incoming missiles at 100,000 km.

You are correct about the cost. The game said it is 30.1 Mc. While the 'credit' has no real world counterpart, this is enough to buy small player-class warships (with all the OP weapons such as 100 km/s sandblaster railguns and smaller 1000 km-range lasers). Install some of them on your asteroids and space stations.

Edited April 28, 2017 by Hypercosmic

[YNM]

3 minutes ago, p1t1o said:

But a silo can withstand all but a direct hit from a high-yield nuclear strike, a satellite can be taken out by a ball bearing. Or at the very least, much much less than that required to knock out a silo.

There are political advantages to having your weapons easily observed as well, and disadvantages to stealthy less-readily-identifyable ones.

I dont imagine that the identification of battlestations would be that much of a difficulty for a determined adversary, there are specific things about them which make them stand out - size, thermal signiture, orbital parameters etc. It is probable that they will be tracked by significant players from the moment thy are launched.

But is still stands that they have one and you don't. Remember the missile crisis ?

 

When deterrence is your real war, you want to be further as possible technologically from your enemy. Real nuclear war is like planting a massive RIP sign all over the Earth.

EDIT : alright, yes I know you might be confused. But intelligence (the agent things not the remote sensing things) will gather what sort of things went away, but not probably where it is.

Edited April 28, 2017 by YNM

[cantab]

I feel pretty confident saying that actually building a 400 MW output laser with a tiny beam divergence will not be easy. If you can build one it's a potent space-to-space weapon, but that's a big if. The cooling system operating at nearly melting point for the materials involved is a big if too. CoaDE is instructive but it's not the final say, and it assumes engineering well beyond what we are presently capable of.

And then space-to-ground is another matter as well. The atmosphere has interesting effects on laser beams.

[p1t1o]

5 minutes ago, YNM said:

But is still stands that they have one and you don't. Remember the missile crisis ?

 

When deterrence is your real war, you want to be further as possible technologically from your enemy. Real nuclear war is like planting a massive RIP sign all over the Earth.

EDIT : alright, yes I know you might be confused. But intelligence (the agent things not the remote sensing things) will gather what sort of things went away, but not probably where it is.

If we are talking real life, and not hypotheticals, then orbiting battlestations are right out. Nobody wants foreign battlestations closer to their heads than their own borders are. They are too likely to start a war by themselves to be considered.

Otherwise, other factors make them less desirable than terrestrial solutions, namely cost effectiveness.

 

8 minutes ago, Hypercosmic said:

This laser draws 1.00 GW, the output is 416 MW (yes, absurd efficiency!) at wavelength of 77 nm. Intensity at 1 km is 552 PW/m², and at 100,000 km is 55.2 MW/m². I assure you, this is enough for disabling incoming missiles at 100,000 km.

You are correct about the cost. The game said it is 30.1 Mc. While the 'credit' has no real world counterpart, this is enough to buy small player-class warships (with all the OP weapons such as 100 km/s sandblaster railguns and smaller 1000 km-range lasers). Install some of them on your asteroids and space stations.

 

btw: 'Impulse shock indicates that the armor is vaporized at a rate exceeding the speed of sound, tearing and damaging the surrounding hull. You can pretty much consider the compartment utterly destroyed.' Yes, CDE renders this thing too.

Though I do not doubt the realism of CoaDE's physics, I do not consider this a realistic weapon. Its all well and good scaling things up until you get really impressive performance, but other factors rule it out. 

NB: the calculator I used before (http://www.5596.org/cgi-bin/laser.php - linked from project rho) gives different, more disappointing results from your parameters, I dont know which version is more correct.

input parameters:

77nm

416MW output

1 second burst

10metre radius lens

 

Results in, @ 50,000km -

0.5MW/cm2

0.23m radius spot size at target

2.6cm of aluminium vaporised

No impulsive shock

 

Still capable of taking out missiles though. IF you can keep your 40cm wide spot on target at this range.

 

[Hypercosmic]

9 minutes ago, p1t1o said:

...Still capable of taking out missiles though. IF you can keep your 40cm wide spot on target at this range.

40 cm wide spot? That's strangely large. Probably because of the distance...

Anyways, I suppose smaller laser arrays are better. This thing is too easy to get sniped. I don't actually use them in real battle.

I have a 100 MW laser with 40.8 MW output and 50 cm radius aperture. The power at 1000 km is not very impressive, at just 135 MW/m², but it has no problem getting missiles with aramid fiber (anti-laser) armor down.

btw, I suggest you to visit our forums. Many people there are much better at lasers than me.

Edited April 28, 2017 by Hypercosmic

[p1t1o]

Just now, Hypercosmic said:

40 cm wide spot? That's strangely large. Probably about distance...

Anyways, I suppose smaller laser arrays are better. This thing is too easy to get sniped. I don't actually use them in real battle.

I think the most important parameter in spot size is the size of the lens, what size were you using?

Its possible that both calculations (CoaDE and whatever the calculator I am using is called) are using different maths or parameters.

But at 50,000km, 40cm still represents a tiny divergence angle, and the ability to keep the spot on target is a significant challenge. Miniscule vibrations, at 50,000km, will spray your laser all over the shop.

 

I think its still obvious from the results that:

Yes, a sufficiently powerful laser can do cool stuff.

Sufficiently powerful lasers are very, very large and technically demanding.

[kerbiloid]

3 hours ago, p1t1o said:

it flipped over mid-ascent

It should. It didn't.

[cantab]

I thought Polyus did flip - a full 360 degrees, instead of the required 180. (Required 180 flip because it was attached to the Energia launcher upside-down). But that's kind of off topic for here anyway.

Edited April 28, 2017 by cantab

[kerbiloid]

https://translate.google.ru/translate?sl=ru&tl=en&js=y&prev=_t&hl=ru&ie=UTF-8&u=http%3A%2F%2Fwww.buran.ru%2Fhtm%2Fspirit.htm&edit-text=

[YNM]

7 hours ago, p1t1o said:

If we are talking real life, and not hypotheticals, then orbiting battlestations are right out. Nobody wants foreign battlestations closer to their heads than their own borders are. They are too likely to start a war by themselves to be considered.

Otherwise, other factors make them less desirable than terrestrial solutions, namely cost effectiveness.

"Risk of starting a war" is, I suppose, the real risk. Sending a missile (well rockets are basically missiles), even indirectly, can cause other missiles to fly for real, immediate harm...

[wumpus]

3 hours ago, YNM said:

"Risk of starting a war" is, I suppose, the real risk. Sending a missile (well rockets are basically missiles), even indirectly, can cause other missiles to fly for real, immediate harm...

There's a reason NASA (and DoD) launch satellites into polar orbits from Vandenberg flying due south* (or at least Vangenberg was chosen so you could launch south).  Rockets heading north (across the pole) look like ICBMs in flight.  Heading south (same orbit, no delta-v difference) makes everybody less twitchy.

* modulo the vector thanks to the rotation of the Earth.

[cantab]

From a range safety point of view, is there anywhere in the lower 48 suitable for launching north? Vandenberg has towns right north of it. From Kennedy the rocket track would be very close to the Florida coast, what if it veers.

[Bill Phil]

2 hours ago, cantab said:

From a range safety point of view, is there anywhere in the lower 48 suitable for launching north? Vandenberg has towns right north of it. From Kennedy the rocket track would be very close to the Florida coast, what if it veers.

I don't think so. Remember, there's a very big nation right North of the continental US. Good old Canada. That and Alaska...