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US Navy's Railgun Now Undergoing Tests in New Mexico

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Re: US Navy's Railgun Now Undergoing Tests in New Mexico

#141
post #38

Earlier quoted context omitted.

But the US Military uses depleted uranium (the hardest material) for tank rounds, so they could make pretty hardy railgun projectiles.

Not the hardest. Bit less than Tungsten so pretty hard but far from hardest. It is used because it is really really dense and hard enough. Perfect for piercing armor.

So perfect for a railgun projectile? :)

What is the hardest man-made substance?

Re: US Navy's Railgun Now Undergoing Tests in New Mexico

#143
post #78

Earlier quoted context omitted.

In the same vein, as an industry, pornography really improved computer storage density and video codecs whereas electronic trading really improved the tech to reduce networking latency. Virtually all engineering benefits from other engineering that came before it. There are plenty of other ways, but this is how it is. Most all of what NASA does or has ever done has directly benefited the Department of Defense. Does t…

> Most all of what NASA does or has ever done has directly benefited the Department of Defense. Especially since a lot of the benefit has gone the opposite direction a lot of times - how many of our space telescopes started life as extra reconnaissance satellites?

This is precisely my point! As much as one might be morally against military research, it is well funded and bleeding edge.

Case in point: I had to get a double bunionectomy when I was in the Army after spending a year in Iraq and got my feet wrecked. They surgically broke my big toe in 2 places and drilled 2 holes. They then put "pins" in each hole made of pig cartilage. This procedure allows the body to heal and then it absorbs these "pins" which prevents arthritis. At the time I got this surgery, in 2004, it was not available to the general civilian population. Now, it is. It was pioneered to help the military and now the entire populace can benefit from the exact same technology.

Problem spaces that push boundaries of engineering ultimately result in better engineer for everyone.

Re: US Navy's Railgun Now Undergoing Tests in New Mexico

#144
post #70

Earlier quoted context omitted.

A combination of three things: 1) The flash is air in contact with the super-hot rail ionizing instantaneously from the heat, and becoming plasma. 2) Friction (From the projectile against both the rail itself, and air) producing vast amounts of heat, which then a) causes water vapor in the air to flash to steam b) produces smoke from burning metal I am not sure how much of the smoke is from 2)b), because I'm assuming…

Nitpick on 2 a): you can't turn water vapor into steam, water vapor is steam .

Is it really that humidity in the air is classified as steam?

Re: US Navy's Railgun Now Undergoing Tests in New Mexico

#145

Earlier quoted context omitted.

I think the interesting use case would be to put things into space for a lot less money. Imagine putting one or many of those new Space X internet satellites into a rail gun that goes straight up. It doesn't need to go all the way into space, it just needs to get pretty high, then the cost to break into orbit can require a lot less fuel and make it a lot more cost effective to do space stuff.

> Imagine putting one or many of those new Space X internet satellites into a rail gun that goes straight up. Orbit doesn't work like that. Getting 200, 300 miles up is the easy part - the vast majority of the required energy comes from going sideways at 7800m/s.

I think they were suggesting that you could save fuel for once you're out of atmosphere, so that you're not fighting air resistance when you start a burn to get into orbit.

Re: US Navy's Railgun Now Undergoing Tests in New Mexico

#146

Earlier quoted context omitted.

I am not foolish enough to predict the future, nor what said future will demand of us. Two nuclear weapons ended World War 2. Seconded guessing hard decisions is a privilege of existing in the future after those decisions were made, a privilege that one might not otherwise have had. Do you feel better about using a nuclear weapon over a chemical weapon? Why or why not? Once death is assured, we’re just arguing time a…

> Seconded guessing hard decisions is a privilege of existing in the future after those decisions were made, a privilege that one might not otherwise have had I dunno... I think a very small percentage of people alive at the time of using nuclear weapons on Japan would have actually done so. My own opinion is that the same percentage today would advocate for using nuclear weapons on another populace. The problem is t…

“I think a very small percentage of people alive at the time of using nuclear weapons on Japan would have actually done so.”

The 300,000 innocent Chinese civilians dying PER MONTH, the estimated 1,000,000 US soldiers estimated to die in the invasion, the countless Soviet soldiers who might have joined them in an invasion, the 10’s of millions of innocent Japanese citizens who would have died in an invasion, all might disagree with you.

And weird how you mention Tibet without mentioning the slow rolling genocide taking place there thanks to their Pacifist leaders.

Re: US Navy's Railgun Now Undergoing Tests in New Mexico

#147
post #88

Earlier quoted context omitted.

Could you hit a railgun with a railgun? Why wouldn't countries build massive anti-ship railguns to prevent any such ship from getting even close to their naval facilities?

> Could you hit a railgun with a railgun? "Smaller than a missile". You could, but it's harder.

Railgun projectiles are smaller than missiles, but the guns themselves aren't smaller, are they?

Re: US Navy's Railgun Now Undergoing Tests in New Mexico

#148

I find the physics of rail guns pretty fascinating. For something nominally invented in world war 1 (1918) which is now "only a few years" away from possible deployment. We are talking literally a 100 years later. We went from powered flight to flying in orbit in less time, think about that. Is it a compelling weapons concept? Of course it is, you don't need explosives to shoot things that is pretty huge. Are wars ba…

I think the interesting use case would be to put things into space for a lot less money. Imagine putting one or many of those new Space X internet satellites into a rail gun that goes straight up. It doesn't need to go all the way into space, it just needs to get pretty high, then the cost to break into orbit can require a lot less fuel and make it a lot more cost effective to do space stuff.

Ronald Reagan was way ahead of you (and everyone else). Back in 1987, the Strategic Defense Initiative (SDI, also known as "Star Wars") featured this concept.

The press excoriated him (hence the derogatory name "Star Wars" being affixed to the program).

The part you mention was called "Brilliant Pebbles", and featured space-based weapons as a cornerstone of the initiative. [0][1]

[0] - https://en.wikipedia.org/wiki/Brilliant_Pebbles

[1] - https://www.nytimes.com/1989/04/25/science/what-s-next-for-s...

Re: US Navy's Railgun Now Undergoing Tests in New Mexico

#149
post #37

Earlier quoted context omitted.

Really hard engineering pushing the limits of physics and materials science is fun, killing people is not.

Do you genuinely see the same virtue in the engineering of a bridge and the engineering of a cruise missile?

For all but the tiniest fraction of human history, nearly everyone alive was enslaved or forcefully controlled by the wicked and strong. If rail guns help maintain this tiny sliver of historic wonder, where people are freer every day, then yeah, they’re exciting.

Re: US Navy's Railgun Now Undergoing Tests in New Mexico

#150
post #113
post #36

Earlier quoted context omitted.

One of the problems with existing Navy "gun ships" is that explosive ordinance can be a hazard to sailors and has to be handled very carefully. Additionally, it has to be stored very carefully. One of the things a railgun hypothetically allows is launching non-explosive inert projectiles. What happen when you launch a big hunk of steel at something 200 miles away travelling Mach 6? Another huge benefit is the speed a…

Existing conventional munitions are absolutely used against surface and air targets.

Yes, but not both. You have ground to air, ground to ground, ship to ground, ship to ship. For the most part (with some standouts that do multi-role such as the Tomahawk) each munition is specialized for a single role. The railgun is being heralded as being capable of doing all 3 for limited use cases, which is fairly unique.
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