Re: GURPS Spaceships, in use!
 

Just read it. It doesn't say that it requires 4000 mps dV to get to Alpha Centauri. It says that it requires that much to do so within 400 years. So the obvious answer to me is to take more time. I'd imagine that you could get by with 1/2 or 1/4 that dV if you were willing to take a few thousand years.

Re: GURPS Spaceships, in use!
 

Yah. I think you missed that the delta-V is per tank. E.g., if you've got advanced fusion pulse at 20 mps/tank and then use 13 tanks for a x1.6 on the delta-V increase table, the delta-V is calculated as follows:

20 mps x 13 tanks x 1.6 = 416 mps. So it's only 10 stages at that TL. Still kind of dubious, though you do better with magsail and the final stage being mostly tank. But in fact, you can do slow interstellar as a practical multi-stage at TL10 and as a single stage at TL11 (TL10 if you go antimatter plasma). And you can reach 10-12% of light as a multi-stage (Daedelus, etc.) at TL11 without too much problem.

Re: GURPS Spaceships, in use!
 

Contragrav? Stardrives? Beam weapons?
Ha!
All you need in enough plutonium.

RICKENBACKER-CLASS "INTERCEPTOR" (TL7)
The standard US Aerospace Force light space combatant of the early 1970s, designed for operations in the Earth-Moon system but capable of making it to Mars (especially after the arrival of more efficient TL8 pulse units in the 80s).

TL: 7
dST/HP: 100
HT: 12
Hnd/SR: -1/5
Move: 2G/8mps
SM: +9
LWt: 3000t
dDR: 10/10/50
Occ: 30ASV
Load: 148t
COST: $163.5 million, plus $150 million fuel (pulse units), plus $66.67 million ammo (even more with nuclear-tipped shells and missiles, which typically made up much of the warload).
Crew is 22
Notes: Designed to fight facing backwards with the massive armour of the pusher plate facing hostile fire.

Front Hull
[1] Light Alloy Armour (dDR 10)
[2] Tactical Array
[3] Defensive ECM
[4] Fuel (150t pulse units)
[5] Fuel (150t pulse units)
[6] Fuel (150t pulse units]
[Core] Habitat (5 cabins, 5 bunkrooms, briefing room, sickbay, rec-room/gym, 45t steerage)

Centre Hull
[1] Light Alloy Armour (dDR 10)
[2] Major Battery (20cm gun)
[3] Major Battery (20cm gun)
[4] Tertiary Battery (10 x 3cm VRF guns), 100t cargo
[5] Major Battery (30 x 40cm missiles)
[6] Fuel (150t pulse units]
[core] Control Room

Rear Hull
[1] Orion Drive (2G acceleration)
[2] Light Alloy Armour (dDR 10)
[3] Light Alloy Armour (dDR 10)
[4] Light Alloy Armour (dDR 10)
[5] Light Alloy Armour (dDR 10)
[6] Light Alloy Armour (dDR 10)

Re: GURPS Spaceships, in use!
 

[QUOTE=dirtysnowball]Contragrav? Stardrives? Beam weapons?
Ha!
All you need in enough plutonium.

RICKENBACKER-CLASS "INTERCEPTOR" (TL7)
The standard US Aerospace Force light space combatant of the early 1970s, designed for operations in the Earth-Moon system but capable of making it to Mars (especially after the arrival of more efficient TL8 pulse units in the 80s).

Nice design! Lots of real guns, none of those wimpy lasers. Now, if we only new what Casaba Howitzer was...

These are good fun A few years ago, I proposed two settings for SJ Games. One was an alternative-history book in which US and Russia happily built all this sort of stuff in the 1960s and 70s and colonized the system; the other was Transhuman Space. I'd still like to do it, actually.

Re: GURPS Spaceships, in use!
 

Most of my generation ship designs putter along about 1/500 of light speed. Be careful you don't exhaust your main power plant, though, and do remember to install either farms or total life support.

Re: GURPS Spaceships, in use!
 

I was assuming that one could (with some difficulty) refuel a powerplant with gasses tapped off a ramscoop.

Re: GURPS Spaceships, in use!
 

That's my melon cannon, baby!

I said it, and I'm glad!

heh

Re: GURPS Spaceships, in use!
 

Possibly. The classic bussard ramjet refuels the power plant, but that does require somewhat exotic fusion reactions; the system as written is more of a ram augmented interstellar rocket design, and just uses it for reaction mass. I wouldn't worry too much, though, as most of the power plants are long duration

Re: GURPS Spaceships, in use!
 

Not 2,600 years long...

The Islands Clusters Campaign places some extreme but very particular demands on a design system.

Re: GURPS Spaceships, in use!
 

Well, I'll buy it in a flash... Maybe an Infinite Worlds ebook?

Assuming that Casaba Howitzer is some sort of weaponised Orion pulse unit, a one-shot plasma beam, I suppose it would be used like a short-ranged X-ray detonation laser. It could be a missile warhead, or fired safely clear of the ship on a small rocket then aimed and fired by remote control.
Unless you just detonate the thing aboard your ship like one of Doc Smith's primary beams...

Full marks for GURPS Spaceships, for me it's the nicest balance of realism, detail (these aren't the same thing), flexibility and playability I've seen in a set of ship design rules. And it lets me build the atomicpunk space battleships that have been orbiting in the back of my brain for years now...
I would like to see the ability to make smaller craft, though. And a Transhuman Space Ship Book (Volume 1), and a pony, and...