Rail guns...

[Shaman]

Here's one! Launching sabot at Mach 5-6 with 0 gun elevation, that punches through 1/8-inch steel plate at 100 yards and keeps flying straight for 7 km. I would love to see satellites launched from equator with long magnetic track, but I guess weapons will be first to be put into operation... what a crazy world, oh well. Here's the video! Wow!

 

http://defensetech.org/2011/04/14/we-were-launching-hypersonic-bricks-at-mach-5-mach-6/

Edited April 14, 2011 by Shaman

[EtherealN]

Launching satellites like that... I dunno. 11km/s flight through thick atmoshpere in a package that can then deploy whatever payload you need sounds like a tricky thing that won't happen for quite a while. Equatorial rotation only reduces that to something like 10.5km/s... That's Mach 32* at ground pressure assuming roughly standard atmospheric conditions. As far as I know we haven't the faintest for a material that would with stand that shock. And of course, the very rudimentary calculation I used assumed no atmosperic drag slowing the satellite down, so... ;)

 

Weaponization vs Satellite launching isn't a question about crazy world, it's about one being technically possible today, the other being pure science fiction.

 

*At least, I think I did the calc right. The numbers here are so huge anyway so I can't sanity check it. :P

 

All of that said: seeing that thing punch through the plate was pretty. Will be interesting to see if they manage to get it into service soon and in which specific role it then ends up.

[Shaman]

Not this way, I thought about giving it initial speed with rail gun, and then satellite would use its own engine. However the initial work to get it off the ground could be use by system of electromagnetic rails. Actually I have been thinking that if international treaty actually allows weaponization of space then we can expect colonies on Moon, then on Mars much sooner then after. I would actually do it the other way around then it is now. Allow military interventions in space, but not on Earth :P

[RIPTIDE]

Great technology to be used for initial missile boosting. Especially for ABM defence where so much of the fuel/mass is used in 1st stage propulsion.

[mig29]

Off topic:

 

Something I found while playing with Newton's equation...

 

v*v – u*u = 2gs

 

Put initial velocity u = 0, g = 9.81 and s = radius of earth = 6400000metres.

v comes out to be 11.2Km/s = escape velocity of earth.

:smartass:

[genbrien]

v comes out to be 11.2Km/s = escape velocity of earth.

:smartass:

pfffff

can run faster in backpedal:music_whistling::D

[blue 22]

im not trying to spam but it seems like the same concept from ace combat 6 estovokians came up with a similar idea to use magnetetic shells to shoot down meteors but the plan was scrapped for it could possibly use weapons like cruise missiles all over the world, then of course meteors hit the nation.

it would be wonderful for the space program but something more advance than the current ICBM system, NATO will be the first to vote no, then the U.N.

[VincentLaw]

Launching satellites like that... I dunno. 11km/s flight through thick atmoshpere in a package that can then deploy whatever payload you need sounds like a tricky thing that won't happen for quite a while. Equatorial rotation only reduces that to something like 10.5km/s... That's Mach 32* at ground pressure assuming roughly standard atmospheric conditions. As far as I know we haven't the faintest for a material that would with stand that shock. And of course, the very rudimentary calculation I used assumed no atmosperic drag slowing the satellite down, so... ;)

 

The altitude required to stay in space for about a year is 450km, with an orbital speed of 7.641 km/s

 

If you assume the earth is perfectly spherical and there is no atmospheric drag on launch, you would need a launch speed of 8.039 km/s to reach this altitude. If you launch with the Earth’s rotation at the equator, you only have to launch at 7.574 km/s. This is Mach 22.82 at standard sea level.

 

Once you get to the orbital altitude, you would need another rocket boost for an additional 0.131 km/s to reach orbital velocity or you would crash back into earth again, so you would still need more than a rail gun to get into orbit.

 

I think the primary idea behind using a railgun to get into space is as a launch mechanism for a scramjet vehicle. For a high speed scramjet to start up, you basically already need hypersonic flow going through it (you cant just takeoff on a runway with a scramjet) but a rail track could probably get it up to Mach 10. This would definitely be useful since thats a large amount of energy that you dont have to store on the vehicle itsself.

Edited April 15, 2011 by VincentLaw

[Heli]

 

U.S. Navy shipboard weapons experts needed energy storage technologies for the future electromagnetic railgun pulsed power system. They found their solution from L-3 Communications Applied Technologies Inc. in San Leandro, Calif.

 

Officials of the Naval Sea Systems Command in Washington have awarded a $7.1 million contract modification to L-3 Applied Technologies for four containerized battery energy storage and charging systems for the electromagnetic railgun pulsed power system.

 

The Navy's electromagnetic railgun project seeks to develop a long-range shipboard weapon that fires projectiles using electricity instead of chemical propellants. Magnetic fields created by high electrical currents accelerate a sliding metal conductor between two rails to launch projectiles at 4,500 miles per hour -- or nearly six times the speed of sound.

 

Supervising work on the Navy electromagnetic railgun are experts the Office of Naval Research in Arlington, Va.

 

http://www.militaryaerospace.com/articles/2016/01/l3-energy-storage.html

[Rangi]

Where does the flame come from in the above pic? Is it just friction?

[VincentLaw]

Where does the flame come from in the above pic? Is it just friction?

It's entirely from aerodynamics, including friction and shocks. Move something fast enough and you turn the air into plasma. There is no fuel or propellant.

[Bushmanni]

Ionized gas glows with the color of the emission spectrum of its atoms so for example air glows blue because of the emission spectrum of nitrogen and oxygen (like in the flash of lightning). Solid matter on the other hand glows red, yellow or white depending on the temperature according to emission spectrum of black body radiation. So based on color of the flame it is composed of small particles of the shell eroded and heated by friction.

[Heli]

for M109?

 

:book:

 

Converting existing rail, or electromagnetic, gun technology along with hypervelocity projectiles developed for missile defense, then using the technology for point defense. Carter said the advanced munitions could be used on Navy destroyers or with Army Paladin howitzers. "We also found that [hypervelocity projectiles] significantly increases the Paladin's range," Carter said.

 

https://defensesystems.com/articles/2016/02/05/carter-dod-strategic-capabilities-office.aspx?admgarea=DS

 

"We tested the first shots of the hypervelocity projectile out of a Paladin a little over a month ago, and we also found that it significantly increases the Paladin's range."

 

http://www.popularmechanics.com/military/weapons/a19285/the-pentagon-wants-to-use-big-guns-to-shoot-down-big-missiles/

[Heli]

 

 

• GA has committed more than USD50 million of internal funding to develop its next railgun weapon system
  
• GA hopes that its successful development will increase US Navy and US Army interest
  

 

General Atomics (GA) told IHS Jane's that it will have committed significant company funds to develop its 10 megajoule (MJ) Multimission Medium Range Railgun Weapon System (MMRRWS) from 2007 to the end of testing in 2017.

 

Speaking to IHS Jane's at the Navy League's 2016 Sea-Air-Space symposium in mid-May, company officials said that GA had committed funds in excess of USD50 million, but declined to be exact.

 

Intended to complement or replace current US Navy (USN) 5-inch guns, if successful, the General Atomics MMRRWS would be able to intercept missiles and aircraft as well as conduct kinetic strikes against maritime or land targets. However in contrast to multimillion dollar missiles, a GA official noted a railgun hypersonic guided projectile could cost between USD25,000-50,000.

 

While the gun's calibre has yet to be determined (perhaps between 90 mm and 100 mm), shells would have an interception envelope similar to the Patriot PAC-3 and initially use a "shotgun" round with tungsten pellets. For kinetic attack the round would have a ballistic range of about 100 km.

 

GA's MMRRWS will be based on technologies already tested on GA's smaller 3 MJ Blitzer railgun that started firing rounds in 2010. General Atomics also stresses its successful development of hypersonic projectiles - often viewed as the more difficult element of railgun technology - must withstand the 30,000 g stress of electromagnetic launch to speeds greater than Mach 5.

 

A GA official explained that the company intends to leverage Aegis radar technology to provide command guidance for shells of the future MMRRWS, adding that the system can be sized for use on small platforms such as the Littoral Combat Ship (LCS) or a frigate.

 

http://www.janes.com/article/60546/general-atomics-commits-private-funding-to-develop-10-mj-medium-range-railgun

[sobek]

Where does the flame come from in the above pic?

 

Good question! I kept asking myself but this thread prompted me to do a little research.

 

Is it just friction?

 

Nope.

 

It's entirely from aerodynamics, including friction and shocks. Move something fast enough and you turn the air into plasma. There is no fuel or propellant.

 

Definately nope.

 

So based on color of the flame it is composed of small particles of the shell eroded and heated by friction.

 

It is indeed the shell but the cause is not friction.

 

Have a look at this picture:

 

https://en.wikipedia.org/wiki/File:3MpUJGm.jpg

 

The complete driving current is passed through the projectile armature, which leads to very high current densities. This heats the armature quickly and turns parts of it into plasma.

Edited May 26, 2016 by sobek

[Bushmanni]

You are correct. I watched some slow-mo videos of the railgun tests and the flame "burns" only for a short distance after the muzzle, after that just crazy intense light bending shockwave.