I have long been following the slow movement of the new classes of weapons via which will one day arm Space Navies. The rail gun appears to be developing nicely and is a hypervelocity weapon, a very good replacement for explosives laden terminal defense, and perhaps even the venerable shipboard 5 inch gun.
US Navy funds Phase 2 railgun maturity effort
The US Navy’s Office of Naval Research (ONR) has awarded BAE Systems a USD34.5 million Phase 2 innovative naval prototype (INP) contract to advance the technology of the company’s electromagnetic (EM) railgun. “During phase 2, we are focusing our efforts on three things: maturing the system to allow for multishot capability, maturing the thermal management system [the higher rate shots that are fired, the better our system will need to be at cooling and prevention of overheating] and incorporating an auto-loading feature,” Dr Amir Chaboki, BAE Systems railgun programme manager, told IHS Jane’s
Perhaps one day we will have to modernize a famous US Navy quote: “Don’t fire until you see the sparks of their railguns!”
“Don’t fire untilyou see the whites of their ions!”?
Just what we need – more weapons for governments to play with, oh and developed with our money.
Certainly gives a different meaning to CHARGE!
ke = 1/2mv2. (kinetic energy is half the mass times the speed times the speed). Projectiles propelled without an explosive charge (in simplified terms, explosions and magnetic flux ignored). But make sure the projectile is not magnetic, lest it be attracted to something in passing, and there are always proximity fuzes in counter-weapons.
Of course, in a power cut, you might want something a little old-fashioned. And what exactly would the Space Navies be fighting?
The rail gun I built produces a large loop of plasma at the muzzle when fired. If you’re close enough to see this, you are well within range and deeper in the scat than you want to be. Adding a shroud to the end of the barrel would mitigate this.
What would Space Navies be fighting? Each other of course.
I fully expect that two Earthly powers will have a shoot out somewhere in the solar system, far from prying eyes, before the end of the next century. Might even have some minor fracas before the end of this decade.
Are rail guns and lasers really appropriate for space-based applications? I would have thought that getting rid of the waste heat would be a significant issue*. Might be a good idea for ground or atmosphere based anti-space weapons though.
*Or maybe military spacecraft will have huge “wings” to get rid of the waste heat. Maybe those guys who build the fantastic sci-fi spacecraft for the films are onto something. đ
AKM,
Huge heat radiating wings will be necessary given what we know now about space. And…they’ll make HUGE targets. Put a few holes in themâŠand your ship is literally toast.
Space combat will be impossible. There’s no place to hide. Once targeted, no way to maneuver enough to escape, especially if the warhead is basically a huge shot gun shell that goes off when it’s close enough to the maximum amount of damage to you.
I really, really don’t see how ship to ship combat will ever be survivable…
Uh…my apologies…that last comment was by me…not AKM. I was thinking about the reply…wasn’t paying attention…
OK…the post disappeared…so…ahhhhhhhhhhh
Trying again:
AKM,
Huge heat radiating wings will be necessary given what we know now about space. And…they’ll make HUGE targets. Put a few holes in themâŠand your ship is literally toast.
Space combat will be impossible. There’s no place to hide. Once targeted, no way to maneuver enough to escape, especially if the warhead is basically a huge shot gun shell that goes off when it’s close enough to the maximum amount of damage to you.
I really, really don’t see how ship to ship combat will ever be survivable…
LCB: Yes… and then again no. đ
I agree that you can’t hide in space. I also agree that you can’t carry the extra weight of armour. So you WILL be seen if the enemy has line of sight to you and you WILL be destroyed if they can fire a weapon at you. This means you need somewhere to hide, and in space the only place to hide is in geosynchronous orbit on the other side of the horizon from your enemies’ ground facilities. You will also need a fleet of largely disposable spacecraft in which the fleet can continue to operate with the loss of a significant portion of it’s component parts. Your fleet will have to spend quite a lot of effort (and propellant) detecting and countering the enemies’ efforts to try and track them while they exploit the high ground by firing missiles over the horizon at the enemies’ ground and space facilities. The really difficult part (and probably impossible as you say) would be moving a space fleet from one planet to take up orbit over another hostile planet.
You are blithely assuming that ‘line of sight’ means you can actually effectually target a weapon at something. ECM -> ECCM -> ECCCM -> etc.
This was the thinking that told us the era of the dogfight is over and all air-to-air combat will be an exchange of long range missile, so why even put guns on fighters? đ
I imagine space combat will be all about jammers and decoys.
I have spent a lot of time thinking about these things. Distance is an important variable because with the exception of pure energy weapons, it can be restated as a delta t. If the delta_t is high enough, maneuver and counter-fire are feasible. For example, if your projectile is traveling at 4 km/s and you are 4000 km away, you have 1000 seconds in which to take action. If you are in a battle situation, you will have thrusters that are causing you to randomly ‘jink’, making it very difficult to predict where you will be 1000 seconds hence.
Remember folks. Space is Big. Unimaginably big. Ships in a fleet will be space hundreds of miles, battles will take place in a battle space 10 or 100’s of thousands of miles (or more) in radius.
As to cooling, there are ways to do that for a warship that you would not do for civilian use. Dump the waste energy into a fluid and flash it to vapour which you then eject for your random motions.
I am sure with a little thinking you can come up with other ways.
I imagine (wistfully) that space combat will be regarded as criminal and passé and that space will be used for trade and fun.
The vast costs of space travel (at current prices) would require vast amounts of capital, which requires capitalism, which requires peace.
Actually energy weapons can be stated as delta t as well. It is just that if it is a laser, the time between detection of the incoming beam and its arrival is zero. Particle beams will have a delta t though. And there will be ways to shield, deflect, avoid, spoof, etc. Just avoid thinking in terms of current ground based technology.
Where there is wealth, there will be those who wish to get rich the easy way… by stealing it. And there will be people who firmly believe that your great wealth is being misused unless you are redistributing it. And there will be still others who will believe that human advancement requires that every human be ‘saved’ (or killed, does not matter to that type) and brought to the One True Belief.
There Will Be War. Count on it.
@ Dale Hemce ‘wistfully’ but, wold the thieves find space travel as far beyond their reach as a Bolivian peasant socialist might find a trip to Liechtenstein?
Blithely is the only way to go!
When trying to spot a space-fleet in space, line of sight “should” mean they can see you as you’re always going to be warmer than the star-field behind you so you should stand out on passive IR*. If they have a nice modern heat-ray at their disposal, it shouldn’t take long for them to swing it around and start cutting holes into your hull. OTOH Missile weapons of any sort are going to be vulnerable to ECM and active missile killing defenses. This is why I suspect that keeping away from line-of-sight would be preferable to our future Space Admirals.**
*I suppose it might be possible to actively cool down one side of your craft to near background and transfer the heat to the other side and emit it there instead, but it would only be worthwhile if you had a pretty good idea where the enemy was. There might also be a benefit to diving out of the sun so their IR sensors are blinded.
**Of course maybe future military battleships will be built inside hollowed out asteroids and will navigate slowly between the planets using vast solar-sails to minimize propellant requirements and heat generation. There are worse armours than meters of rocks and you could probably dump some of the waste heat from your own lasers and rail guns into the rock itself. Hmmm, starting to like this idea đ
You weapon must intersect the cross-section of the target normal to your viewpoint. If the target ship were a sphere, the math gets easier… if I had the time right now to do it. If R_target is the radius of the target and r_distance is the distance to the target (assuming a beam or physical weapon where the cross section of the weapon normal to the target is << than R_target, then you angular pointing accuracy must be better than r * sin (theta). There will always be some r such that a pointing accuracy of some theta is beyond current capabilities. However... it is more complex. The target gets a vote. By randomly jinking about the line defined by R_target, it can make it unlikely that it will be inside the target circle when the ordinance arrives. If it is EM weaponry, then it is just a matter of decreasing the probability of an intersection of the beam with the the targets cross section; if it is matter, then it can actively avoid the fire or fire counter ordinance. There will of course, at any R_target distance, be a number of shells, beams or what have you that raise the probability of an intersection to near 100%. In between this there is a lot of room for tactics and smart use of weapons.
Just as an additional example, if the engagement is fought at R_target = 3,000,000 km, even a light beam will take 10 seconds to arrive. If the ships is randomly
jinking at 1G, it may have shifted position by far more than its radius in 10 seconds. Assume it randomly jinks for 1 second at 1G, then it the centre of its target cross section will have moved in a random walk of 10 segments of 5 meters each. The chance of a hit from a single beam is probably quite small, even if the pointing accuracy is well under the required theta.
Actually I may have been misleading to those not familiar with the assumptions inherent in vector sums and velocity versus acceleration in the above. Each 1G acceleration in a new direction does not start from zero relative to its initial vector; the velocities caused by each acceleration are additive.
“Don’t fire until you see the whites of their eyes” is ‘rabble’, not Navy: uttered at the battle of Bunker Hill (and other places earlier).
Correct. I have it stuck in my mind along with a bunch of naval ones: “I have not yet begun to fight”, “You may fire when ready, Gridley”, “Damn the Torpedoes, Full Speed Ahead.”
You might be wrong about line-of-sight battles. If some asteroids have rare earth elements, they would be valuable, and fighting in the asteroid belt would give you the cover you need.
Also, I think that people will go beyong my original idea, mentioned some years ago, of harvesting plasma to build hydrogen atoms as fuel for ships. they might be able to actually build up atoms of any type, including the transuranium elements that are simply hypothetical for now. the safest place to build them and study them would be in space, and if they proved valuable, then you need to protect them, and transport them to where you want to use them.
Dale, I remember a short video I saw several years ago that simulated a possible space conflict. It showed small, robotic, octagonal craft which could move abruptly in many directions with small jets, and used lasers, if I recall correctly, instead of projectile weapons because of the effects of recoil.
Does any of that sound plausible?
(As an old sci-fi fan, I’m with you—when humans go into space, their flaws and faults go with them. There will always be conflict.)
It fits within the parameters I noted above. I presume you mean at octagonal solid. Probably makes for cheaper construction if you are assembling them in a ‘classical’ fashion. With composites, 3D printers, nanotech coming along, the simplification may not be needed. A sphere maximized volume, minimizes structure and minimizes cross-section; it allows you to put critical things deep inside with all the outside areas being sacrificial. The abrupt motion matches the ‘drunk walk’ technique I suggested as a way to minimize the probability of being hit. Lasers are currently pretty inefficient but the technology is young. Although I do not know this for a fact, my gut feeling is that railguns are at present tech levels more efficient, ie less waste heat. However, if you do a spherical vehicle, you can make the outer shell contain water, which is good radiation shielding, a good place to dump heat and probably good for shielding against energy weapon hits, although there are both problems and opportunities to that idea.
‘Phased Plasma Rifle in the 40 Watt range’ ‘We don’t do those buddy’….
This guy has built a couple of hand held railguns.
These are the guns of near future and are not railguns:
http://ukarmedforcescommentary.blogspot.it/2013/07/a-new-golden-era-for-naval-guns.html
Basically Italian Oto Melara 127mm with new Vulcano ammo a 100km rounds range and also their successful 76mm plus the US 127(5″).
A recollection of battles in space.