Miscellaneous Terran question-and-answer thread

[RedDwarfIV]

I'm going to assume the TCA don't have the technology yet, but if you can collect it, there's a lot of antimatter in the Van Allen belts.

And if the TCA were okay with ORION drives, they could have bomb-pumped gamma ray lasers.

[Nemo]

Define a lot? As I recall its about 150 nanograms of AM. E=mc^2 makes that roughly 4 kilowatt hours of energy.


I mean, its more than we can make dirtside, but not enough to be useful in this context.

[RedDwarfIV]

Yeah, but its always being replenished. Leave collecting stations in the belts and you'd probably get quite a lot after a while. Besides, the concenntration is higher in Earth's magnetic field, so it's easier to collect it here than at Jupiter.

[GeoModder]

... or near the Sun.

[ThatsNoMoon]

lasers and railguns? yes it's coming, and lasers are already around, railguns not quite there yet...kinda like fusion power, but it probably WILL work which is not certain about fusion any time soon....not talking about how to POWER these babies either, that is gonna be an issue.

Powering everything is an issue.

Unless you think beam weapons won't have massive power requirements. Especially given those magical fields that keep beam cohesion. So yeah...

Power is easy, it's dumping the waste heat that's hard. Damn near unsolvably so. D:

For combat purposes, Railguns are somewhat more functional than LASER technology at this point.
The LASER systems deployed are exclusively anti-missile systems due to the severe limitations of current designs. Some people will tell you it's because using them on living beings would be a war crime, and while that is technically true the real reason is that they are terribly inefficient at anything else.
Meanwhile, prototype naval Railguns have tested out with firing energies of 33MJ per shot. That classes it as anti-heavy-armor, but they can be built to any lower specs. It's also possible to design and build systems with variable muzzle energy.

[discord]

moon: yes, works under laboratory conditions, problem are and will be fire rates, barrel lifespan, energy budget and finally munitions for quite a while.

lets just take energy budget, take the 33MJ example and compare fire rate of the 16" guns on the iowa class(nine guns twice per minute, which can mean three shots the first minute, but lets stick with 2/minute equals 18 shots/minute) 33x18=594, taking conversion losses and such into account, you would need one of the two main reactors on a aircraft carrier just to power the guns and equal fire rate(but not damage output) to the obsolete scrapped ship from WW2.

there is a reason i often say that railguns will bring back the BB, but right now, the ancient BB from WW2 is still superior.

[GeoModder]

Just wondering, but wouldn't one hit from a 33mj railgun projectile equal several if not dozens of 16 inch granate hits? Higher energy transfer to the target and all that.
OTOH, a railgun probably becomes a line of sight weapon fairly quickly, so not really usable for targets over a planetary horizon...

[Hālian]

Well, if you're going over the horizon, you have to take gravity-induced curvature into effect.

[fredgiblet]

Just wondering, but wouldn't one hit from a 33mj railgun projectile equal several if not dozens of 16 inch granate hits? Higher energy transfer to the target and all that.
OTOH, a railgun probably becomes a line of sight weapon fairly quickly, so not really usable for targets over a planetary horizon...

According to the Navy it will work quite well as long range bombardment. That's part of the reason they're going for them, you can have long-range bombardment capabilities that euqla to the old battleship rifles in a smaller package.

[ThatsNoMoon]

moon: yes, works under laboratory conditions, problem are and will be fire rates, barrel lifespan, energy budget and finally munitions for quite a while.

lets just take energy budget, take the 33MJ example and compare fire rate of the 16" guns on the iowa class(nine guns twice per minute, which can mean three shots the first minute, but lets stick with 2/minute equals 18 shots/minute) 33x18=594, taking conversion losses and such into account, you would need one of the two main reactors on a aircraft carrier just to power the guns and equal fire rate(but not damage output) to the obsolete scrapped ship from WW2.

there is a reason i often say that railguns will bring back the BB, but right now, the ancient BB from WW2 is still superior.

Your numbers are off.
18 shots at 33MJ a piece would equal 594MJ, but that's over the course of a minute. Using a power buffer, such as an array of capacitors, would make the average power draw for your 9-gun array would be 9.9MW. The largest naval reactor in use at the moment is 165 MWe, and as you would not deploy an electrically-powered weapon on a ship class with weak power source it suggests your calculations assume the railguns have a total system efficiency of about 6%.

Of course you're also assuming that the guns have the same ballistic properties and would be used the same way. That is not accurate.
The 16"/50 Mark 7 had a muzzle velocity of up to 820m/s.
The prototype railgun in question has a muzzle velocity of approximately 2722m/s.
The 16" guns fired explosive munitions in banks for saturation, and because they were imprecise as a result of both the physics involved and the targeting systems in use.
Kinetic impactors are not fired for saturation, nor are modern targeting systems so crude.
The 16" guns had a maximum range of 38km.
Near-deployment railguns have an effective range of 160km.

Then there's other practical concerns. Rounds for railguns take up only a tiny fraction as much space as chemically-propelled rounds, meaning that far more can be carried in the same space. Kinetic impactors, unlike chemical propelled munitions, also pose no risk to the crew in the event of a fire or other emergency.


The 33MJ round is only fit for laboratories at the moment, but the US navy intends to put a mach 5 (~1701m/s) railgun into a testing deployment in 2016.

[GeoModder]

According to the Navy it will work quite well as long range bombardment. That's part of the reason they're going for them, you can have long-range bombardment capabilities that euqla to the old battleship rifles in a smaller package.

Of course, but at the cost of kinetic energy impact because it needs to be fired at a lower velocity. I bet that at that stage the old 406 mm guns still do better.

[discord]

moon: right, forgot the over time part, my bad.
on damage output, as a kinetic kill weapon it has pretty good punch, yes....but it is not equal to a metric ton of High Explosives....needs to be quite a bit faster to do that.

"accurate enough to hit a 5-metre (16 ft) target over 200 nmi (370 km) away while firing at 10 shots per minute." <---- that is what i call bullshit, without prescience(seeing the future) it would be impossible to pull that off with a ballistic weapon, simple changes in air pressure and wind during travel would see to that, and before you rattle off about guided munitions the electronics of those would have to be VERY well shielded to survive the magnetic field and the actual guidance system survive the acceleration(much higher than a ordinary cannon)

"9 MJ is enough energy to deliver 2 kg (4.4 lb) of projectile at 3 km/s" <---- how large projectiles will be used? how to get effective damage on target or area denial witch such small munition? this is the other part of the munition problem i mentioned, and it also illustrates that the gun might very well need more than 32MW, side note, effective energy of the 16" gun is 403MW per shot...just saying.

do note, i am personally optimistic about railguns, will probably be fine weapon systems, but there are still issues to hammer out, fire rate and barrel life are two major such and both relate to thermal efficiency.

Geo: not really, KEW vs HE are two rather different beasts.
and 1200kg at 820m/s is a hell of a lot of kinetic energy, when most of that weight is high explosive.

[ThatsNoMoon]

moon: right, forgot the over time part, my bad.
on damage output, as a kinetic kill weapon it has pretty good punch, yes....but it is not equal to a metric ton of High Explosives....needs to be quite a bit faster to do that.

Horseshoes and hand grenades. Obviously a kinetic kill weapon that misses is going to be ineffective, but kinetic energy hitting a target is far more effective than explosives hitting near a target.
You can't compare a railgun to a 16" gun. They're entirely different beasts.

"accurate enough to hit a 5-metre (16 ft) target over 200 nmi (370 km) away while firing at 10 shots per minute." <---- that is what i call bullshit, without prescience(seeing the future) it would be impossible to pull that off with a ballistic weapon, simple changes in air pressure and wind during travel would see to that, and before you rattle off about guided munitions the electronics of those would have to be VERY well shielded to survive the magnetic field and the actual guidance system survive the acceleration(much higher than a ordinary cannon)

It always boggles my mind how much people overestimate the difficulty of shielding. Shielding is easy, even against very strong fields.
The difficult part is hardening the electronics against thousands of Gs of acceleration. That's hard to do, but still doable.

This is all mute, since the Navy has been using guided rail slugs in tests. They work.

"9 MJ is enough energy to deliver 2 kg (4.4 lb) of projectile at 3 km/s" <---- how large projectiles will be used? how to get effective damage on target or area denial witch such small munition? this is the other part of the munition problem i mentioned, and it also illustrates that the gun might very well need more than 32MW, side note, effective energy of the 16" gun is 403MW per shot...just saying.

Using a railgun for area denial is a bit like sniping with a rocket launcher.

You're confusing energy and power. The 16" guns had a muzzle energy of about 20MJ. The 403MW figure tells us the firing time is 1/20th of a second, which isn't particularly useful since it's chemically propelled so the power doesn't matter.

[icekatze]

hi hi

Do you have a link to something demonstrating Navy's guided rail slugs? I looked, and all I can find are articles from 2012 stating that the Navy would like to have them at some point in the future. (And who wouldn't?)

[JQBogus]

Just a nitpick...

IIRC, the great majority of a 16" shell's mass was steel. More than 90% on standard shells, and more than 95% on AP shells.

Getting fired out of a monstrous cannon, and being expected to punch through a dozen or more inches of armor steel before exploding takes a lot of strength!

[discord]

"and a high explosive round designed for use against unarmored targets and shore bombardment." <---- probably quite a lot of boom stuff in that one, only 69.67kg, but that is still lots of boom stuff.


moon: 1200kg and 820m/s equals 403440000 joules, and since joules and watt are pretty much the same thing really....or not, but still, whatever, too tired to write straight.
my bad, used incorrect data, the speed was for the lighter HE rounds while weight was for the super heavy AP, correct numbers are.

reference
http://en.wikipedia.org/wiki/16%22/50_c ... Mark_7_gun <---- mark 8 super heavy shell
http://www.csgnetwork.com/kineticenergycalc.html <--- 1200kg and 762m/s = 348386400 joules or 348MJ.
http://www.navweaps.com/Weapons/WNUS_16-50_mk7.htm <--- correct ammo numbers

[Onaiom]

Since we saw that Loroi have an interstellar shuttle, do humans have an interplanetary equivalent (like an Earth-Moon-Mars "airbus") ?

What about Evacuation pods ? They exist in this setting ? If they do exist, human's ships use them?

And repair drones ? Nowadays ROVs can make repairs at boats and platforms that humans cannot attempt. There is an equivalent in the battleships ?

What are the types of the human civilian vessels ? There are Fast Freighters carrying 300 tons, Haulers dragging 3,300 tons and/or Bulk Freighter that loads 20,000 tons of cargo ?

And the Colony Ship ? A massive vessel capable of carrying a compact city (colonists, heavy machinery, prefabricated buildings and supplies). There are any ?

[Arioch]

Since we saw that Loroi have an interstellar shuttle, do humans have an interplanetary equivalent (like an Earth-Moon-Mars "airbus") ?

I think the economical way to do it would be to have (2001 style) atmospheric shuttles that bring you into orbit, and then dedicated non-atmospheric orbital transfer vehicles that take you from station to station. There might be single-stage-to-moon vehicles, but I think they'd probably be luxury yachts for the very wealthy. The Loroi "Highland" shuttle is essentially the latter -- a VIP transport.

What about Evacuation pods ? They exist in this setting ? If they do exist, human's ships use them?

Spaceships don't sink, so I don't think there's a strong need for lifeboats. But any large ship will surely have several utility shuttles.

And repair drones ? Nowadays ROVs can make repairs at boats and platforms that humans cannot attempt. There is an equivalent in the battleships ?

I think it's logical to expect that repair crews will use a variety of tools, including ROV's.

What are the types of the human civilian vessels ? There are Fast Freighters carrying 300 tons, Haulers dragging 3,300 tons and/or Bulk Freighter that loads 20,000 tons of cargo ?

Just as today, I'm sure there are dozens if not hundreds of different types of civilian ships.

And the Colony Ship ? A massive vessel capable of carrying a compact city (colonists, heavy machinery, prefabricated buildings and supplies). There are any ?

The all-in-one colony ship sort of makes sense in a slower-than-light setting, or in a strategy game, but I don't think they're realistic. The cities in the New World were not created by "colony ships", but rather by multiple trips of many ordinary transport and cargo vessels.

[Onaiom]

Spaceships don't sink, so I don't think there's a strong need for lifeboats. But any large ship will surely have several utility shuttles.

Space is very dangerous. Spaceships don't sink, but they can explode violently. Bellarmine and Winter Tide are good examples.


Since humans are at TL10, it’s safe to assume that every (or most) of the technology of TL8 was mastered, miniaturized and can be mass product ?
For example:
- Fusion Power Cells are common. Vehicles, energy weapons and general machinery use them.
- Cybernetic organs and members can be easily created and used on medicine. Ships can monitor life condition of it host.
- Laser personal weapons are the standard now. Powered by fusion power cells, they can be deadly at any combat and range.
- Rail guns mitigate the previous chemical propelled weapons. Since they do not require chemical propellant, storing ammunition is safer and reduces the magazine weight and volume. Powered by Fusion power cells.
- Also, a soldier (in TCA case, a Marine) would typically wear a Combat Infantry Dress (possibly sprayed with ablative foam), a helmet with HUD and communicator, carries either a rocket carbine, military laser rifle or an assault railgun carbine. The rifle or carbine has an attached laser scope, with HUD sights, and probably a mini grenade launcher. For close combat, he/she uses a vibroknife.

[Arioch]

Spaceships don't sink, so I don't think there's a strong need for lifeboats. But any large ship will surely have several utility shuttles.

Space is very dangerous. Spaceships don't sink, but they can explode violently. Bellarmine and Winter Tide are good examples.

If the ship is going to explode you probably won't get much advance warning, but if somehow you do, you can board a shuttle or get into a spacesuit as easily as you can get into an escape pod. Maybe if you were working in low orbit, some kind of pod that could survive reentry could be useful. But I don't see the advantage otherwise.

Since humans are at TL10, it’s safe to assume that every (or most) of the technology of TL8 was mastered, miniaturized and can be mass product ?
For example:
- Fusion Power Cells are common. Vehicles, energy weapons and general machinery use them.
- Cybernetic organs and members can be easily created and used on medicine. Ships can monitor life condition of it host.
- Laser personal weapons are the standard now. Powered by fusion power cells, they can be deadly at any combat and range.
- Rail guns mitigate the previous chemical propelled weapons. Since they do not require chemical propellant, storing ammunition is safer and reduces the magazine weight and volume. Powered by Fusion power cells.
- Also, a soldier (in TCA case, a Marine) would typically wear a Combat Infantry Dress (possibly sprayed with ablative foam), a helmet with HUD and communicator, carries either a rocket carbine, military laser rifle or an assault railgun carbine. The rifle or carbine has an attached laser scope, with HUD sights, and probably a mini grenade launcher. For close combat, he/she uses a vibroknife.

As I mentioned in a different thread, I sometimes use GURPS terms to help describe stuff in my stories, but they are not set in any GURPS world or based on the technology in the GURPS books. Just because you see something in GURPS Ultra-Tech doesn't mean it's in Outsider.

There's a lot in this thread about the kind of technology humanity has, and the kind of weapons they use.