Good point...
Here are the questions that necessarily follow:
1. Have they overcome the issue of rail erosion? Early rail guns ate the rails into uselessness after 2-4 shots.
2. Have they resolved issue of payload? The accleration forces encountered and the ferocious electromagentic energies and induced heat pretty well eliminated any kind of conventional explosives, fuzes, detonation trains. And please don't give me the "kinetic energies of the superfast projectiles will devastate whole grid squares" horsepucky - all projectiles decelerate to their aerodynamic terminal velocities when they get into the decending branch of their trajectories. What do we get for our 6 minute wait - a 40 pound hunk of iron?
3. Given the problems of 2. above, what kind of terminal guidance is available? A 100 mile shot is a long ways for a nonrotating projectile to fly and still expect it to be anywhere near a point of aim. The Paris Gun shot 93 miles but it had a range probable error the size of Paris itself. Not particularily effective. In the world of artillery, noise is useless, hitting is everything.
4. Let's get back to the 6 minute time of flight. Unless you are shooting at a large stationary target - like a building - 6 minutes is an eternity, particularly if the target is coming towards you. 6 minutes is almost completely useless in most combat scenarios, since most worthwhile targets move.
Lastly, to answer the whiz kids out there with the correspondence school degree in physics, yes there is huge recoil: Newton's Third Law is still in effect. The hand-wavy stuff I have read so far about "magic magnetic fields" is sadly wrong. Add that to the large RF pulse at launch which will give the firing platform's position away to the entire world when it fires, there are lots of issues yet to overcome before the rail gun is more than a cash cow for major defense contractors.
How did they derive that? At 5,600 mph, the flight time would be 64 seconds (100/5600 * 3600).
I see it in the article, but I'm a bit skeptical -- unless they are considering a ballistic trajectory that has a high apogee.
The article suggest GPS guidance, but I'm curious about that. I'm sure a receiver could be ruggedized to withstand the forces of launch, but I don't know if it's possible to build a receiver that could provide guidance at that speed.
And that's separate from the problem of the ionized plasma that is created by hypersonic flight through the atmosphere. I don't know the speed at which it first occurs, but it does only occur at the leading edges. The shuttle was able to maintain communication by transmitting "out the top" to TDRS relays.
That's what I'd guess.
Mount the (low angle) railgun on a frictionless puck and see if you don't score an own-goal.
Good point...
Being a veteran of putting many rounds of naval gunfire to practical use, the whole concept has intrigued me for some time...
First, the “projectile” used during this initial testing seems to be rather klunky for lack of a better term, for now...I do not see a ballistic coefficient in that design...I’m sure that it was the rifle’s firing mechanism that was mainly being tested so far...And improved projectile must be in the works...One with many different end result type surprises...VT frag, HE, AP, etc etc etc...
I do not see it being used in a conventional sense either...Considering the range, it appears ot be more of one of thiose weapon systems that would be used in a more strategic sense than anything else, from what I can see...So the bang for the buck is going to be critical for practical usage...
Also...Would not the initial surge of energy to propel the projectile be in the breach, and not necesarily along the “rail” or barrel of the rifle??? I guess from my initial reaction, would there be a great need of contact with the “barrel” to effect any stabilizing spin from rifling with normal chemical propellants we see with the rest of the worlds gun technology??? I just don’t see the need, unless the stabilization affords something to assist in the projectiles accuracy before leaving the barrel “rail” portion of the device...Contact, would not be necessary with any physical surface since the magnetic pulse could be used to effect a low to nil parasitic drag due to physical contact with the rail “barrel”, right???
I mean look at the levitation you get with some of the magnetic rail systems for trains, and those types of transportation systems...Right???
Nothing actually touches anything when the system is charged and operating...At least that is kinda where I am going here...
So my deal is will the effectiveness of the impact of the projectile on target be sufficient (massive) enough to warrant its continued development...I actually think this is going to HAVE to be a projectile with some sort of HE or other chemical explosive capabilty, other than just a kinetic impact, even though that might be interesting to see what a 40 pound projectile does to a target from 100+ miles away...
Also on a practical note...If you only have to load projectiles, you no longer need massive storage spaces for propellant, which limits/mitigates the chance of extended damage from fire, and other potential combat related factors...So to me that would be a plus...
The design of the ship can accomodate more bang for the buck, mitigate the need for significant designs to contain a potential carastrphic failures if those storage magazines are hit in a combat or accident situation (only if the projectiles are kinetic impact in nature) if they develop rounds that explode, well, obviously you will have to have some firewalls,and other safety features to protect the ship and crew...
I’m just thinking outside the box...Some of you physics majors know a bit more about the system and its mechanisms for it to do its job than I do...
I am only approaching this from a practical usage standpoint...