Making EM Guns Viable in Space Combat (3e)

[Polydamas]

Moving back to the original topic, I am told that the hard science wargame Children of a Dead Earth has a lot of very rapid fire railguns shooting ~1 gram projectiles at ~3-10 km/s which ablate their targets. Their heavier railguns and coilguns shooting projectiles in the hundreds of grams or kilograms tend to be specialist close-range weapons with a lower 'muzzle velocity'. Those are different assumptions than the assumptions in GURPS Spaceships, not sure about GURPS Vehicles 3e. But it shows that depending on your assumptions about future technology you can have a place for different kinds of electromagnetic guns.

And its GURPS Spaceships pp. 28, 29 which assumes that its relatively large, low-velocity electromagnetic guns shoot projectiles which can redirect themselves towards a target (page 59 suggests that they have 'muzzle velocities' on the close order of 3 km / s). That is a GURPS 4e product, other rules make different assumptions!

[Fred Brackin]

Originally Posted by Polydamas

not sure about GURPS Vehicles 3e.

!

The 3e gun design rules that I know about were in Ve2 and EM guns were mostly just a modifier on the conventional gun design sequence (grav guns too). You may not have been able to make a gun smaller than 1 mm but there was no particular limit on how big you could make one.

I made one once that was big enough to launch the Lunar Shell from G:Steampunk and it ended up in G:Steam-Tech.

The 1mm ones were pistol-sized and made me think of the slugthrowers from the Andromeda TV series.

There are reasons why some of us would _really_ like a new version of Ve2.

[Refplace]

Just woke up with a dream about something related and quickly adjussted my thoughts to something relavant. Not read this thread past the first page or so when it started so apol;ogizes if this been said or drifted to another topic.
EM guns are probably low power compared to energy weapons but lack the speed and self guidance of missile weapons. I think that makes those two choices superior for capital ships.
EM guns though could be useful for point defense and on fighters.
Fighters would have low power outputs - making energy weapons harder.
Fighters have low volume to carry large missile racks.
Fighters are small and likely maneurvable though and could use EM weapons to save power and space, though liikely have a few missiles too.
Its why we still give jet fighters guns, even though the missiles are primary armament. Pilots will want something as a backup and guns also can work against low armor targets like other planes.

Furhermore an EM weapon combines the speed of the fighter in its kinetic energy. And if you shoot at an oncoming ship you get to add its velocity to your own. In a high velocity combat that suddenly becomes very attractive.

[Rupert]

Note that a 'fighter' in space is effectively a missile 1st stage that returns to the firer (hopefully). Thus if a fighter is viable, a missile is more viable - it doesn't need it's 1st stage to return home, saving on fuel, weight, etc.

[Fred Brackin]

Originally Posted by Rupert

Note that a 'fighter' in space is effectively a missile 1st stage that returns to the firer (hopefully). Thus if a fighter is viable, a missile is more viable - it doesn't need it's 1st stage to return home, saving on fuel, weight, etc.

This is where you mess about with the superscience.

If you can't build a reactionless thruster smaller than a fighter engine you can't build small cheap missiles with equal endurance but your reactionless first stage/fighter can provide unlimited Delta-V and act as a bus for a lot of small cheap missiles.

[Prince Charon]

Originally Posted by Fred Brackin

This is where you mess about with the superscience.

If you can't build a reactionless thruster smaller than a fighter engine you can't build small cheap missiles with equal endurance but your reactionless first stage/fighter can provide unlimited Delta-V and act as a bus for a lot of small cheap missiles.

At which point the question is 'why not just use a drone,' for which there are a number of answers, though my go-to is 'reactionless drives are psychotronic, and can't be automated yet.' Not helpful in a setting without psychotronics, though.

[Fred Brackin]

Originally Posted by Prince Charon

At which point the question is 'why not just use a drone,' for which there are a number of answers, though my go-to is 'reactionless drives are psychotronic, and can't be automated yet.' Not helpful in a setting without psychotronics, though.

You can also use fighters at ranges where even remote control by com lasers isn't practical and an onboard AI that you can trust as much as a trained human with Fire/Don't Fire decisions is not likely to be small and cheap.

[Rupert]

Originally Posted by Fred Brackin

This is where you mess about with the superscience.

If you can't build a reactionless thruster smaller than a fighter engine you can't build small cheap missiles with equal endurance but your reactionless first stage/fighter can provide unlimited Delta-V and act as a bus for a lot of small cheap missiles.

Absolutely, but if you want a consistent setting, it does need to be addressed. So should 'fighters vs battleships', probably.

[Anthony]

Originally Posted by Rupert

Absolutely, but if you want a consistent setting, it does need to be addressed. So should 'fighters vs battleships', probably.

The straightforward way to have 'fighters vs battleships' is by having two core drive technologies with different preferred scales. In the traditional case, it's because water drives get more efficient as you get bigger up to some enormous scale, whereas aircraft drivetrains don't scale up very well.

[RyanW]

Originally Posted by Fred Brackin

2 of those were by the Royal Saudi AF) and maybe 1 helicopter gunned down by an A-10. Many of the radar kills were at night too and from single-seater fighters. No guy-in-back needed.

And the most modern systems seem to be in the process of rendering eveything between "tree top level" and "edge of space" an instant death zone for anything that isn't coated in a billion dollars of classified documents.