
US Navy's Railgun Now Undergoing Tests in New Mexico - SEJeff
https://www.thedrive.com/the-war-zone/28669/navys-railgun-now-undergoing-tests-in-new-mexico-could-deploy-on-ship-in-northwest
======
ChuckMcM
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 bad? Of course they are.

That said, the concept has been around for a hundred years, so people _are_
going to work on making a practical weapon out of it. Which means that at some
point its going to be a component of a military action. And not having one of
your own, will change the calculus of what you can and cannot do.

~~~
mabbo
The concept is the same for any projectile weapon: I'm going to convert stored
energy into kinetic energy.

Bow and arrow? Stored energy in the bow turned into kinetic energy in the
arrow. Handgun/cannon/musket? Stored chemical energy in some compound, quickly
converted into kinetic energy in the bullet via exploding.

A rail gun isn't much different- it's just a different means to store the
energy (in electrical storage) and a different means to apply the energy to
the projectile (magnets). The real problem is that these two changes require a
lot of overhead in terms of gear to make it work. It's only worthwhile to do
it if you intend to really, _really_ add a lot of kinetic energy to something.

It's the same reason the electric car has taken 100 years to finally be
worthwhile- chemical energy is much more dense and easy to convert into
kinetic energy. Battery tech is only now catching up to the point that it's
worth doing.

~~~
steve19
You put it well. The problem of of putting energy into projectiles caused a
move from kenetic to chemical weapons (missiles).

But delivering chemicals to a target is expensive and at some point scaling it
up becomes politically dangerous (you cannot just lauch even a conventional
icbm without all sorts of risks).

Scaling up kenetic weapons ended up with huge battleship guns that did almost
as much damage to the ship itself as the target (OK, a bit of an overstatement
but I doubt any of those sailors left the navy with hearing intact). They were
slow to fire, extremely heavy, and required a lot of dangerous chemicals to be
stored. One mistake and the ship would blow up.

This allows deep penetrating weapons containing huge amounts of energy to
pierce bunkers from way over the horizon.

This is the kind of weapon the Navy will want if the Korean peninsula ever
heats up to a boil.

Edit: I suspect I am being downvoted because I am discussing weapon systems.
There is a difference between advocating for weapons/war and discussing them.
It is better weapons are discussed in the open, than developed in secret where
the public cannot weigh in. Truly horrifying things are born in the dark.

~~~
PopeDotNinja
> ...huge battleship guns ... were slow to fire ...

I was curious about how fast battleships could actually fire, so I googled
around and found a couple stats.

On an Iowa class battleship:

\- Armed with nine 16"/50 caliber Mark 7 guns [1]

\- Each 16" gun is quoted as having a firing rate of 2 rounds per minute [2]

\- Each shell weighed between 1900lbs / 865kg and 2700lbs / 1225kg pounds [3]

So math says 2 rounds/minute * 9 guns is 18 shells/minute. That is 34_200 lbs
(18 * 1900) and 48_200 lbs (18 * 2700) of ordinance per minute. I would not
want to be on the receiving end of that!

EDIT: fixed some numbers I goofed after @CapricornNoble was kind enough to
point them out. Thanks!

[1] [https://en.wikipedia.org/wiki/Iowa-
class_battleship#Main_bat...](https://en.wikipedia.org/wiki/Iowa-
class_battleship#Main_battery)

[2]
[https://en.wikipedia.org/wiki/16%22/50_caliber_Mark_7_gun#Se...](https://en.wikipedia.org/wiki/16%22/50_caliber_Mark_7_gun#Service_history)

[3]
[https://www.cs.mcgill.ca/~rwest/wikispeedia/wpcd/wp/i/Iowa_c...](https://www.cs.mcgill.ca/~rwest/wikispeedia/wpcd/wp/i/Iowa_class_battleship.htm)

~~~
steve19
Interesting but I don't think that's sustained fire.

You see crazy him rpm for firearms. The rate of fire is restricted by the
magazine size (ship guns do have magazines) and how fast the gun can cool.

The US Army changed the barrel of the M4 Carbine (automatic rifle) after some
troops during a sustained defense of some hill had barrels failing after
glowing white hot. Machine guns often have barrels that can be replaced during
prolonged engagements.

A hot naval gun could detonate the charge if it overheats. It has happened
although I don't remember how long ago.

~~~
dredmorbius
The Maxim gun (1880s - WWI-era) and M1917 Browning machine gun machine guns
were water-cooled.

Barrel heating is indeed a problem.

------
mcguire
1) " _The system charges for two minutes..._ " One shot per two minutes is
pretty bad; the current 5" gun shoots 16-20 rounds per minute.

2) "...at speeds up to Mach 6." One of the issues with old school, large
caliber naval guns was that the blast from the guns would damage or destroy
equipment near the muzzle. (I was just reading _Pursuit_ by Ludovic Kennedy,
about the British pursuit of the Bismark, and (IIRC) one ship (the Prince of
Wales?) had its bridge windows blown out when firing the B turret "over its
shoulder".) Is the shockwave from a railgun going to be similarly dangerous?

~~~
RantyDave
No because "chemical" guns accelerate their loads by putting enormously high
pressure gases behind them. Obviously, then, once the load is off the gases
spew out the end (and make a really, really loud bang noise). Railguns, IIRC,
use a chemical charge to get the first couple of mach but then the magnets to
pull the load to full speed so it's not followed out the barrel by a mountain
of hot gas.

The flames you see coming out the end are chemical charge and/or bits of the
sled melting and it travels down the barrel. (people who know better, please
feel free to correct me)

~~~
gricardo99
Thanks, that answers a question I had about the flames/discharge after the
round exits. I expected to see nothing other than the round.

------
pneill
Does anyone know why there is a flash of light and a puff of smoke when the
gun fires? Since it's electromagnetic, you'd think you wouldn't see anything.

~~~
JDulin
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 the
surface materials are designed to minimize friction and therefore surface
burning.

[1] [https://www.quora.com/When-a-railgun-is-fired-where-does-
the...](https://www.quora.com/When-a-railgun-is-fired-where-does-the-muzzle-
flame-fire-explosion-come-from?share=1)

~~~
semi-extrinsic
Nitpick on 2 a): you can't turn water vapor into steam, water vapor _is
steam_.

~~~
RantyDave
No, it's water vapour. Steam is a gas.

~~~
semi-extrinsic
Water vapour is steam, i.e. it is the gaseous phase of water mixed with other
gases (N2, O2, etc). Just like liquid water is still water if you mix it with
alcohol. There is no possibility for a phase transition.

------
dfilppi
Get the projectile up to mach 33 and it can shoot satellites out of orbit from
the ground.

~~~
keiru
It's going to be interesting to see non-state actors get their hands on a
railgun. Possibly handed by a state actor, of course.

~~~
IanSanders
Same applies to nukes, and now I'm scared

~~~
rtkwe
Yeah there's been several scifi books written where the ease of access to
things like diy-bio and manufacturing being miniaturized pose a huge threat by
letting more and more people have access to the ability to make a new plague
or bombs. Rainbow's End by Vernor Vinge is one I'm fond of.

------
sandworm101
Some forgotten limitations of railguns: There is a maximum speed for
projectiles in naval warfare. Earth is round. So anything moving too fast
(~8000m/s) simply cannot hit distant targets. If fired horizontally, the shell
will climb up as the earth curves away. This causes all sorts of difficulties
if trying to attack another ship. At best, your shells will hit horizontally,
far _above_ the waterline. You would need a shell that could either fly itself
downwards, bleeding speed, limiting penetration, and defeating the point of
using a railgun.

~~~
cascom
Article references a goal of achieving a 100 mile range? How do they plan on
doing that then?

~~~
credit_guy
Meanwhile, the Army is aiming for a 1000 mile range [1]

[1][https://www.google.com/amp/s/www.military.com/defensetech/20...](https://www.google.com/amp/s/www.military.com/defensetech/2018/09/14/army-
eyeing-strategic-cannon-tech-1000-mile-range.html/amp)

------
stcredzero
It looks right. It looks like it could well be the ancestor of the MAC cannons
from Halo.

EDIT: I said this to my coworkers a couple of weeks ago: I'm calling it now.
Either 1) Naval Railguns also wind up being killer AA weapons and there aren't
any game changers in submarine warfare or 2) Railguns are going to be the
equivalent of WWII naval cannon -- They won't be nearly as important as
something else.

~~~
ohaideredevs
"2) Railguns are going to be the equivalent of WWII naval cannon -- They won't
be nearly as important as something else."

Railguns would completely surpass missiles for StS warfare, which can be
intercepted by other missiles, whereas a railgun shot cannot at this time.

~~~
vosper
Except maybe not these hypersonic missiles, which were discussed here just the
other day?

[https://news.ycombinator.com/item?id=20227021](https://news.ycombinator.com/item?id=20227021)

~~~
qball
Sure, but missiles have to propel themselves, are very large compared to
railgun projectiles, and are easier to break apart by putting a heavy wall of
lead in the air.

Railgun projectiles have none of these disadvantages. They don't need
propellant (or a warhead; the energy delivered upon impact is more than
sufficient to break things without needing to explode), they're a solid
projectile (and as such can't be as easily destroyed or knocked off course),
and they're smaller than a missile is making them much more difficult to
track.

To successfully defeat an incoming railgun projectile, it would both required
sufficient detection technology coupled to a laser that would need to fully
ablate it; where missiles require detection of a significantly larger object
and can be defeated by shooting at them/more active protection measures.

~~~
pm90
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?

~~~
AnimalMuppet
> Could you hit a railgun with a railgun?

"Smaller than a missile". You could, but it's harder.

~~~
xyzzy_plugh
Indeed, we don't typically resort to shooting bullets at bullets to defend
incoming gunfire.

~~~
maccam94
[https://en.wikipedia.org/wiki/Trophy_(countermeasure)](https://en.wikipedia.org/wiki/Trophy_\(countermeasure\))

(Granted, it's more anti-missile than anti-bullet)

~~~
fkdo
Missiles are bigger (they carry their own engine and fuel), are in the sky
longer due to their longer range, and shooting missiles from the sky has never
been implemented with a high success rate in active combat.

------
openasocket
I've never quite understood why we need to change technologies so completely
to get the projectile moving faster. As in, why couldn't we do the same thing
by just making a bigger explosion in the barrel? I assume there's some point
of diminishing returns or inefficiency that makes it impractical, but I
haven't been able to find a source that gives the math to explain it.

~~~
dogma1138
To make a bigger explosion you need a bigger barrel and more powder charges.

Eventually you hit a limit where you simply can’t create enough pressure to
propel the projectile faster and not turn the barrel into a pipe bomb.

For the most part many guns have already hit their practical limit in this
regard.

There is a good reason why battleships fell out of favor other than the US
being the only blue water navy after WW2.

Those big guns are a bitch they are slow to reload and you can’t be anywhere
near the muzzle including good couple 100 yards of the bow of the ship when
those fire.

Also powder takes up space and weight, takes time to reload and it can explode
when ignited.

Having a gun with parts that don’t explode intrinsically when set on fire is a
pretty big advantage for any combat vehicle or vessel, not needing to carry
propellant for your rounds is also a huge plus because you can carry more
rounds or other munitions and supplies.

~~~
UnpossibleJim
It isn't only that, with a powder charge you are pushing the projectile with
an explosion. That explosion will also cause a disturbance on a ship, until
you get to a pretty enormous size, you have to calculate that into your
trajectories. With a railgun, you have a series of magnets pulling a
projectile forward incrementally faster. It's a lot less energy wasted into
the environment, meaning a lot less energy put back into the ship. These
larger guns could be put on smaller ships and calculated with greater accuracy
with greater ease due to less wasted energy put back into the ship and gun,
I'm guessing.

~~~
Zelizz
What you are describing is a coilgun, a railgun uses a slightly different
principle.

~~~
UnpossibleJim
Oh. Ok, I'll have to look into that. New project to look into for the summer
=)

------
module0000
Sadly, news these days involves a lot of "we've invented <X>, to kill people
that disagree with us". Often the word "disagree" is replaced with "undermine"
or "threaten". It's all the same human-life-ending bullshit. I don't feel at
home in this world any more. When I was 18, I enlisted in the armed services
and "did my part" as people often say. What a fucking mistake, I'm humiliated
and embarrassed every single day to have played "my part" in any of this. The
modern-day me wishes I could go back to the 18-year-old me and turn my weapon
on my masters when they were all gathered to cheer us on. Unfortunately, I'm
sure dozens would have stepped in to take their place as quickly as I ended
them.

------
zw123456
You could rule a punkin chunkin contest with that if you could find a way not
to pie :)

------
tick_tock_tick
Does the logo the navy use for railguns show it shooting intercontinental?

~~~
sdinsn
It's just a logo, I think the Railgun only can get to 100 miles or so (at the
moment).

~~~
clarkmoody
Someone a little better with aerodynamic drag computations could do a quick
back-of-the-napkin to figure out the maximum range of something fired at sea-
level going Mach 3,4,5,6,etc. The biggest issue I see is just vaporizing the
projectile on launch, so there would be an upper bound on muzzle velocity
based on projectile material properties.

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

~~~
sharpneli
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.

~~~
SEJeff
So perfect for a railgun projectile? :)

What is the hardest man-made substance?

~~~
RantyDave
Artificial diamond? But it doesn't matter - you don't actually want something
hard because you don't _actually_ want it to go all the way through and out
the other side. You want it to dump all that lovely kinetic energy into
whatever it's hit.

~~~
SEJeff
Yeah, DU has an incendiary property along with a "self sharpening" property.
It doesn't mushroom as much when used as a sabot round as tungsten. My platoon
sergeant in the US Army was a former tanker and we learned all about it (I
flew the Shadow 200 TUAV).

------
Fej
Why have coilguns not gotten the same amount of attention as railguns?

~~~
leetcrew
I'd guess the main reason is that it's an inherently more complicated design;
if you don't sync the electromagnets perfectly you spend energy decelerating
the round. it does have the advantage that the projectile doesn't need
physical contact with an electified rail, so maybe it could be less damaging
to the device itself.

~~~
shereadsthenews
These railguns also have synchronized pulsed power systems that are quite
complex. The University of Texas has been researching this stuff for decades.
Here's a simple paper I Googled up
[https://apps.dtic.mil/dtic/tr/fulltext/u2/a639371.pdf](https://apps.dtic.mil/dtic/tr/fulltext/u2/a639371.pdf)

------
travisporter
Is there any active research on this technology for non-rocket launch systems?

~~~
godelski
Do you mean like going to space? There's some research but after everyone
figured it that all humans inside would be instantly squished they started
researching other avenues. The g forces are pretty large and would damage a
lot of cargo too.

~~~
ars
> would be instantly squished

Not so. That's only for a very short launch. You would actually have a track a
few miles long (probably up the side of a mountain) and launch using that. The
g-forces would be very mild.

~~~
logfromblammo
You need about 1200km to reach LEO from the equator with max acceleration of
about 3G.

I did the math once, and a track from the Galapagos Islands to the peak of
Chimborazo on the continent in Ecuador would do it.

~~~
ars
I was a little shocked at that number, so I ran the math again, and wow.

Quite a bit longer than I expected.

Maybe a circular track till you build up speed, then switch over to the
mountain track?

Of course the circular track would have g-forces due to that..... (Do you feel
like doing more math?)

I guess it's more practical to use the track just for the initial boost above
the atmosphere, then a rocket to add speed. Also a track that can handle
something moving at km/s is .... not easy.

~~~
logfromblammo
A circular track means you'd have to accelerate the vehicle inward
proportional to the square of the velocity.

If target exit velocity is 11 km/s, and the acceleration of the straight
portion of the track is insignificant compared to the circular portion, in
order for the combined linear and centripetal accelerations to stay under 3G,
I'd make each component 20.8 m/s^2.

So if 20.8 m/s^2 = (11000 m/s)^2/r, then r has to be 5800 km. Closing the ring
at that radius makes the circumference larger than the distance needed for a
linear track.

Untrained humans could not ride it up to Earth-escape velocity. LEO only needs
about 8 km/s. So that requires a radius of 20.8 m/s^2 = (8000 m/s)^2/r, 3000
km. Still too big.

What if we bump the G threshold to 5G? Then centripetal portion of the
acceleration should top out at 34.7 m/s^2, and required radius drops to 1850
km.

Okay, cargo only then, just to LEO. 25G max acceleration, 8000 m/s exit
velocity. Radius 370 km, circumference 2300 km. Still more track than needed
by a linear launcher.

It's always cheapest to put all the acceleration towards moving the vehicle in
the direction you want it to go, instead of wasting some energy pushing it in
different directions that ultimately cancel out.

You could use a spiral track, but the final leg of the spiral is going to have
an effective radius so large it might as well just be straight the whole way.

------
fnord77
I wonder how durable these will be in combat

Seems vulnerable to damage during a battle. A couple stray bullets or shrapnel
hitting those power cables would put it out of commission unless it was
heavily armored.

where as they would just ping off an old-timey cannon harmlessly.

~~~
russdill
old-timey cannons need a lot of systems to slew/aim/etc. And without these
systems, they are useless.

------
spookybones
As usual, I find the music in all of the linked videos delusional, as if this
high-tech killing machine was created to astonish patriotic five-year-olds.
For the sake of analogy, someone should overlay the same music to the
engineering of a-bombs and gas chambers.

~~~
doctorRetro
I agree on at least the first half of your statement. Although I'm not sure
I'd say 'delusional' as much as - I don't know? - Jingoistic? Bombastic? I
feel like I should be playing Command and Conquer to that sound track. At the
end of the day, these are killing machines that are being designed to take
human lives, and it does feel more than a bit inappropriate. I think that's
what you're getting at with the latter half.

~~~
toomuchtodo
A friend overlaid an EDM track (Flux Pavilion if I recall) on the original
test fire videos from several years ago when the prototype was located at the
Virginia test site. I enjoyed the short piece of creative they remixed in the
same way I enjoyed the Iron Man franchise. It’s a killing machine, but the
engineer in me still deeply appreciates the advanced technology these systems
are based on (energy/thermal management, power control systems).

SpaceX vehicles are a firmware update away from being high precision ICBMs
(and their CEO has said they’d take DoD work and build weapons systems). No
one on here is calling for somber treatment of that kit and their YouTube
launch streams. Condemn the action, not the tool.

~~~
minikites
>Condemn the action, not the tool.

So it's fine to stockpile chemical weapons as long as we don't use them
because they're just a tool?

~~~
toomuchtodo
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 and the experience.

War in general is terrible and merciless, and should be avoided at all costs.
I can be a pacifist but still want to pull out all of the stops when the devil
comes knocking.

~~~
module0000
> 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 that the people in charge of these things
aren't in the majority - they are psychopathic power-hungry war mongers. Have
you ever heard of an instance where a pacifistic head of state ruled a nation,
beyond Tibet? I have not - those types of people tend not to interested in
becoming head of state in the first place. People who aspire to dominate a
nation(ie presidents, prime ministers, emperors), don't have a huge moral leap
to make(if any at all) before they are willing to murder another nation's
people.

tldr; anyone who is capable of being made a leader of a nation, should never
be allowed to do so. they tend to be willing to murder people to get what they
want, and that's generally bad for the rest of us living on planet Earth.

~~~
ThrowawayR2
> _I think a very small percentage of people alive at the time of using
> nuclear weapons on Japan would have actually done so._

Ever talked to any older Asians from nations who were occupied by the Japanese
before and during the war? They would have happily used as many as the United
States was willing to provide.

It's amazing how many people forget the immense scale of the atrocities that
the Japanese committed before and during WWII, eclipsing even that of the
Germans.

------
alistproducer2
Am I supposed to celebrate the spending of untold billions on an unnecessary
weapon of death while my Bridges and roads crumble, my health care system
sucks and absolutely nothing is being done about, or to prepare for, climate
change?? I'm not impressed

~~~
deweller
Is there a widespread lack of funding for bridges and roads infrastructure in
the US?

The bridges and roads around me in middle TN are well maintained. These are
funded by local government resources, right?

~~~
Tuna-Fish
The reason there were such problems in this area until recently was
congressional earmarks.

When people lobbied for their representatives to support their pet cause,
traditionally the best way they had to do this was to issue an earmark as part
of some bill. Earmarks are not heavily fought by other representative because
they _do not give federal money to a state_ , rather they are the federal
government forcing a state to spend some of their own money on something they
wouldn't otherwise have done. The problem with this is that unless the local
government decides to overbudget for this and run a surplus every year, this
money comes from somewhere. Typically something boring that people don't care
about, like infrastructure maintenance. That is, people don't care about it
until it starts to actually fail...

Then congressional earmarks got banned. Only, things are actually worse now,
because it turns out the political horse trading around earmarks was the only
reason representatives have to compromise across party lines, instead of
always holding a hard line on the issues their supporters want. This is the
direct cause of the current political gridlock.

------
jiveturkey
No mention of China. I wonder if the revival of this is due to China's railgun
developments.

~~~
crimsonalucard
I find this invention will solve our problems. Just point at China, fire the
gun, and all problems solved.

Just kidding, seriously what do we point it at? And what problem will it solve
after it's been fired?

Also why are we not competing on high speed rail technology? Why do we always
have to beat a country with military technology given how completely useless
most of it is.

~~~
adventured
> Also why are we not competing on high speed rail technology?

The US competes at the top in dozens of other categories, from aerospace to
biotech to software to agriculture to semiconductors to spacetech to medtech.
Why should we need to compete in high-speed rail technology?

It's the last problem the US has. There's no need to dominate everything - as
no nation practically can anyway - just buy Japan's excellent high-speed rail
tech. If the US were going to build a national high-speed rail network, it
would be best served to buy that tech elsewhere rather than reinventing the
wheel, so as to save money and time. The high-speed rail that gets built in
Texas for example should probably use Japanese tech:

June 2019: "Japan's 'supreme' bullet train aims to impress Texas with speed"

"The real audience for the demonstration, however, was the stakeholders of a
privately constructed high-speed rail line in the U.S. state of Texas
connecting the cities of Dallas and Houston."

[https://asia.nikkei.com/Business/Companies/Japan-s-
supreme-b...](https://asia.nikkei.com/Business/Companies/Japan-s-supreme-
bullet-train-aims-to-impress-Texas-with-speed)

~~~
crimsonalucard
Three things.

1\. I'm talking about public government projects like the space race or
international highway system. Not commercial business sectors like biotech,
software or agriculture. Typically governments do projects for the good of
society or to compete for prestige (which offers no tangible utility) with
another country. I'm thinking kill two birds and instead of building a gun
they will likely never fire, build a huge public bullet train system that
actually benefites society and makes America not look like a giant car mono
culture.

2\. My mistake, I meant the rail network infrastructure itself not the
technology.

3\. Not only is there no need for the US to dominate every industry. There is
no need for the US to dominate at all for the industry I'm talking about and
that is government projects. The rail gun serves a single purpose. Prestige,
that's it. With globalization taking over the world today, firing that rail
gun at any country is just bad news for everybody and unlikely to happen at
all so why build it at all.

Governments should serve utilitarian needs of the people. Governments should
not build projects just to one up another country. Seriously who cares if
China's GDP surpasses the US... It doesn't matter in the end.

------
antpls
Could the same technology be used to help the lift off of Falcon9-sized space
rockets from a deep vertical tunnel ?

~~~
ars
See here:
[https://en.wikipedia.org/wiki/Mass_driver](https://en.wikipedia.org/wiki/Mass_driver)

You actually want horizontal velocity, not vertical. Getting "up" is easy
(it's only a few miles), it's the horizontal speed that keeps you there.

The only reason rockets launch straight up is to avoid the thick air as
quickly as possible, then they turn and accelerate sideways the rest of the
way.

~~~
logfromblammo
Or they do a gravity turn to round off the corner, largely in the same manner
as that one math problem you probably did in school that involved finding the
fastest path that includes running on the beach for some distance, then
swimming at slower speed to a point in the water.

Also, different rocket designs have different efficiencies at different
outside pressures due to overexpansion or underexpansion of the exhaust plume.
Kicking a rocket out of the atmosphere--or at least up to a lower pressure
altitude--with a big gun first stage changes the requirements a bit for the
second stage rocket engine. It's slightly more efficient.

But the biggest advantage is that you aren't ever accelerating the fuel for
the first stage along with the rest of the vehicle. The disadvantage is that
you need a very long track if you don't want to reduce vehicle occupants to
thin red paste with excessive acceleration. Also, you can evacuate the gun
barrel and put one or more plasma windows at the end, so your initial
acceleration doesn't have so much atmospheric drag.

------
drewbt
In South Africa, we are putting our weapons in art galleries, as relics.

The art of war days are over.

That Art of Peace struggle is gaining momentum.

~~~
pageandrew
that's not how the world works

~~~
drewbt
How does it work, how should it work, and what are we doing about it?

~~~
toss1
How it works now is that some percentage of the humans want to become, and/or
want to support authoritarian rule. Authoritarian rule always wants to
expanad, and will treat both it's subjects and other people as objects.

How should it work? Like eradicating smallpox, we'll need to somehow engineer,
or teach, or by some other method, eradicate from the entire human race the
authoritarian impulse.

Until then, the choices are: 1) submit, or 2a) create systems of laws &
institutions to ensure that power remains distributed and is difficult to
hijack/co-opt/capture by any one person or group and 2b) (since all systems
are hackable/fallible) be prepared to fight for your freedom and the freedom
of others less fortunate.

EDIT: add 2a

~~~
drewbt
“Hi Drew/Glenda It is with great pleasure to see the project at this stage. We
have yet once again proved the sceptics, nay sayers and persmists wrong. From
a plain field to a sight commanding building that yields hope to drags of our
society and the future itself. Despite of the hindrances we have encountered
along the way, I am humbled, awed and jubilant to have been a part of such a
gesture. In this money fueled life style I would also been delighted to have
made myself a fortune in building such a building that is going to make a
difference in many people's lives but the greatest fortune of all is the joy I
find in knowing that these hands have built such a meaningful building. The
project may have come to its end but the memory will linger in my heart
forever. This hasn't only equipped me with skills but changed the way I view
life. It is this reason that I would love the organisers to allow us to keep
the tools we have used in building the hope and the future of our society so
that we can continue putting bread on our tables and helping those in need of
our assistance. My humble thanks to all those who selflessly opened their
check books and offered with their hard earned cash to the project, and not
forgetting those who could not offer funding but took it upon themselves and
used their precious time to personally give a hand in this project. This
project is a full proof that humanity/Ubuntu still exists. Regards Michael
Dyasi”

