Steve Jackson Games - Site Navigation
Home General Info Follow Us Search Illuminator Store Forums What's New Other Games Ogre GURPS Munchkin Our Games: Home

Go Back   Steve Jackson Games Forums > Roleplaying > GURPS

Reply
 
Thread Tools Display Modes
Old 12-04-2014, 10:08 AM   #11
Rysith
 
Join Date: Oct 2013
Default Re: Space Opera Semi-Psuedovelocity Drives

What if the travel mode of these drives was quite easy to disrupt? Then, it seems like dropping to 'real' speeds would be enforced by the opposing fleet rather than a cooperative effort, nicely separating 'combat' from 'travel'. It would also (with your rules about decelerating without constant reactionless-drive acceleration) mean that a missile volley launched at travel speeds would be more or less stopped dead when it entered the combat envelope of it's target, preventing that too.
In theory an engagement could happen where nobody engaged their disruptors, but since that would mean ceding the speed advantage to the enemy it seems unlikely to happen.
Rysith is offline   Reply With Quote
Old 12-04-2014, 11:48 AM   #12
Varyon
 
Join Date: Jun 2013
Default Re: Space Opera Semi-Psuedovelocity Drives

Quote:
Originally Posted by Rysith View Post
What if the travel mode of these drives was quite easy to disrupt? Then, it seems like dropping to 'real' speeds would be enforced by the opposing fleet rather than a cooperative effort, nicely separating 'combat' from 'travel'. It would also (with your rules about decelerating without constant reactionless-drive acceleration) mean that a missile volley launched at travel speeds would be more or less stopped dead when it entered the combat envelope of it's target, preventing that too.
This is kind of how I have it working now, except the interdiction effect isn't a voluntary one - the drive and disruptor are one and the same.

Of course, this does bring to mind what could be a rather effective screening method for carriers - send out a bunch of unmanned/remotely piloted interdiction vessels (small craft with semi-reactionless drives) to surround your vessel at a given distance. Any enemy that comes within 5,000 yards of the interdiction ships instantly loses its pseudovelocity. So, if you've got your interdiction ships flying 10,000 yards away from you, incoming missiles/fighters/whatever may find themselves halted a full 15,000 yards away. Even a Move 100/500 missile (the fastest "craft" currently available) is going to take around 32 seconds to cross that distance, buying an extra 20 seconds of PD fire (assuming you have PD that can actually hit that far away, of course).

This implies a counter-strategy of sending an initial wave (or more) of fighters/missiles to blow up the interdiction ships so that your main force doesn't get slowed early. Could be interesting.

Of course, what will probably work better, as stealth in space is not exactly easy, is to do away with the idea of ablative interdiction ships and instead to launch your own fighters to intercept whatever you detect being inbound. A 4-drive fighter (probably typical for a superiority fighter) can boost at 36G, allowing it to reach that 10,000 yard distance in a little over 7 seconds.

I'll probably have a smaller, cheaper version of the drive available that doesn't generate any velocity - pseudo or real - but serves only to produce an interdiction field, for use in satellites and space colonies.

Quote:
Originally Posted by Rysith View Post
In theory an engagement could happen where nobody engaged their disruptors, but since that would mean ceding the speed advantage to the enemy it seems unlikely to happen.
There are actually advantages to both sides if they don't engage their disruptors - a quick flyby is probably less likely to result in casualties than a dogfight, and a foe that is moving faster than 500 yards per second - a little under 0.3 mps - wouldn't be able to use a blaster without hitting itself (as it is going faster than its bolt). I think I prefer if the targets don't actually have a choice (synchronizing is really only a hack to allow a fleet to travel together).
Varyon is online now   Reply With Quote
Old 12-04-2014, 06:09 PM   #13
Culture20
 
Join Date: Feb 2014
Default Re: Space Opera Semi-Psuedovelocity Drives

Perhaps the "energy field" is also the defense field. You'd want to highly encrypt or modulate on an agreed upon pseudo random set of frequencies so that you could sync with friends but not foes (to whom you would be defenseless).
Culture20 is offline   Reply With Quote
Old 12-04-2014, 10:18 PM   #14
DangerousThing
 
Join Date: Mar 2013
Default Re: Space Opera Semi-Psuedovelocity Drives

Old Space Opera, as opposed to New Space Opera, usually had no computers as we know them today. Most of the things we use computers for now, they used people.

For example, in one of the Lensmen books, they built a flagship mainly for command and control. It had a large room with a 3d map of the surrounding space, and people used long sticks to move the small ship "tokens" that represented the fleet and the bad guys.

The hellbores (ship heavy blasters that actually took ammo) had people taking the old stuff out and putting the new ones in.

Each gun, or maybe each cluster of guns, was individually aimed and fired.

This means that the quality and number of people under your command was as important as the hardware. A well trained crew that worked well together could be the difference between success or failure.

This also means that something which might take us only a single operation might take these people several. For example, to plot a course change, one had to take data from several sources, calculate a new course, and then manually input the new course. This wouldn't apply during a dogfight when the fighter pilots flew by the seat of their pants, but it would apply to missiles which would be difficult to automate and would require somebody controlling them.

The computers they had would be more like giant calculators and the big ones would require specialists.

The end result is that the skills of the PCs would matter much more in a fight than one with normal ultra tech devices. A high skill might make it possible for a skilled pilot in a junkyard fighter be able to have a chance against the newer fighters.
__________________
A little learning is a dangerous thing.
Warning: Invertebrate Punnster - Spinelessly Unable to Resist a Pun
Dangerous Thoughts, my blog about GURPS and life.
DangerousThing is offline   Reply With Quote
Old 12-04-2014, 10:52 PM   #15
DangerousThing
 
Join Date: Mar 2013
Default Re: Space Opera Semi-Psuedovelocity Drives

If you don't like the capacity of capacitors, then design new ones. When I designed a space opera game I had most ships use accumulators with a really huge capacity.

The ones used for space ships were expensive because the crystals were purer than the ones used in civilian devices. Even still, an accumulator in a floater (a contra grav car) was about the size of a can of Coke and the floater could circle the globe a couple of times on a full charge.

I measured the charge in Power Point (PP) - Weeks. To recharge one fully, it takes a lot more power than it can hold because as the charge builds up, it is more difficult to put more charge in. Basically it took the total PP-W to change the accumulator to 1/2 its value. Continue like this until as full as you want it.

Example, I'll fill a small accumulator of 8 PP-W.

To fill the first half (4 PP-W), it takes 8 PP-W of energy. To fill the half the remaining space (2 PP-W) takes another 8 PP-W. To fill the next half of the remainder (1 PP-W) takes yet another 8 PP-W, and to simplify things, the rest takes 16 PP-W. So it basically takes 5 times the power capacity to charge one of my accumulators fully.

I did this because of time rather than expense, though it would cost money also usually.

I did this because I liked the idea of having energy weapons that shot thousands of rounds. While most ships did contain a small fission reactor for recharging the main accumulator if they couldn't get back to civilization, it would take a LONG time to do the recharge.

Just an idea.
__________________
A little learning is a dangerous thing.
Warning: Invertebrate Punnster - Spinelessly Unable to Resist a Pun
Dangerous Thoughts, my blog about GURPS and life.
DangerousThing is offline   Reply With Quote
Old 12-05-2014, 08:51 AM   #16
Varyon
 
Join Date: Jun 2013
Default Re: Space Opera Semi-Psuedovelocity Drives

Quote:
Originally Posted by Culture20 View Post
Perhaps the "energy field" is also the defense field. You'd want to highly encrypt or modulate on an agreed upon pseudo random set of frequencies so that you could sync with friends but not foes (to whom you would be defenseless).
The drives and shields are explicitly different technologies - the first interacts with hyperspace, the second with subspace*. Additionally, I want it to be possible to kinda-sorta synch with enemy shields, such that you can blast past them when they flicker and actually hit the target.

However, another problem (ugh) I've run into is an extension of the interdiction concept from my previous post. As it stands, the best way to deal with an incoming fleet of fighters is to send out a single tiny missile as soon as you detect them. You'll drop their pseudovelocity to null, giving you ample time to escape. The counter to this would be for the fighters to carry a bunch of antimissile missiles so they can stop the missiles using the same trick, then skirt the perimeter of the missile's combat range to keep up their velocity. This could easily devolve into massive swarms of missiles on either side, and I don't want that.

I think I've come up with a solution, which basically comes down to drive mass. First off, I should note that vessels that are synched and within combat range of each other count as a single unit - coming within 5,000 yards of one vessel in such a fleet slows all of them, but the drive mass of all of them are added together. For reactionless drives, they are automatically slowed if hostile drive mass is within 1/10th or 10x that of the vessel/fleet. For larger disparities, the larger vessel/fleet can choose to interdict or not. For semi-reactionless drives, any reactionless drive will automatically interdict, while hostile semi-reactionless drives follow the above guidelines. All interdiction is mutual.

So a missile swarm cannot interdict a group of fighters unless said missile swarm is massive - typical fighters probably have 3 drives, while missiles essentially have 10, so total missile mass must equal 1/30th total fighter mass. A single SM+5 fighter would require around 15 missiles (typical missiles are 16 cm) to interdict. That same fighter could interdict up to 10 equivalent fighters (a space superiority fighter, with 4 drives, could interdict up to 13 or so typical fighters) or a carrier/capital ship of any size.


*The "hypercosmology" of the setting is that our plane/universe/whatever exists between two others, hyperspace and subspace. Ships can transition to hyperspace, which is full of a gas-like medium called aether (technically, the Hyperspacial Medium), which is what the drives interact with. It correlates perfectly well to our universe (to the extent that large bodies have a "shadow" in hyperspace), except that something like every inch in hyperspace corresponds to something like a mile in real space (I still need to work out what the ratio is). Subspace has the opposite relationship, but don't want to transition a ship there - nor would you want to, as all experiments indicated matter that goes there is outright ripped apart and energy is absorbed and dissipated about as quickly (which makes it ideal for generating a shield).

Quote:
Originally Posted by DangerousThing View Post
Old Space Opera, as opposed to New Space Opera, usually had no computers as we know them today. Most of the things we use computers for now, they used people.
While it's Space Opera, the setting is meant to take place in the future, not an alternate reality or a long time ago in a galaxy far away. There has been some tech regression, but not to the extent of getting rid of computers. The setting, of course, still needs a bit of work, but as it stands it could probably be described as "safe-tech, minus nuclear energy, plus cybernetics and neural interfaces."

Quote:
Originally Posted by DangerousThing View Post
If you don't like the capacity of capacitors, then design new ones.
My problem with capacitors isn't their capacity, actually, although I do intend the HEDM systems* to be higher. My issue is a multifaceted one. I want fighters (and carriers, as they need to recharge the fighters) to have volatile systems - for the former, this allows a single lucky (or well-aimed) shot to utterly destroy the fighter, for the latter this helps justify boarding parties. I'm also not too crazy about fighters being able to readily recharge themselves, which electrical energy can lend itself to. I may allow capacitors to be available, but they'd only hold 1 PPh or so (but be able to discharge arbitrarily fast - a 6-drive fighter could burn out a capacitor in half a minute).

*My current thought is that an HEDM cell holds 10 PPh, and can discharge up to 60 PP at a time - enough for 3 drives and some change for weaponry (note shields are actually self-sustaining, but leaving them on too long can cause overheating issues). It costs 50K for an SM+5 cell (that is, price is +1 SM relative to fuel cells). Each fuel tank of HEDM provides a further 20 PPh, and refueling an HEDM cell costs half as much a refilling an HEDM fuel tank. However, the blasters in the setting are a lot more energy-hungry than typical SS beam weapons, due in large part to their much higher RoF - an equal-weight capacitor will power an RoF 1 weapon for only 200 shots. That means each such weapon requires 18 PP to operate, just like a drive (I swear, this actually wasn't planned, it just worked out this way). For something equivalent to an X-Wing, which is a space superiority fighter, you'd probably have 4 drives, 2 HEDM cells, and 4/3 blasters - that is, a Medium Battery with 3 blasters, and a mixed battery of 1 Medium Battery blaster and a missile launcher.
Varyon is online now   Reply With Quote
Old 12-07-2014, 01:54 AM   #17
Zeta Blaze
 
Join Date: Jul 2014
Default Re: Space Opera Semi-Psuedovelocity Drives

What happens when a ship mounts
a Semi-Reactionless and a Reactionless drive?
What happens if you turn both on at the same time?
Zeta Blaze is offline   Reply With Quote
Old 12-07-2014, 09:42 PM   #18
Seneschal
 
Seneschal's Avatar
 
Join Date: Jul 2009
Default Re: Space Opera Semi-Psuedovelocity Drives

Quote:
Originally Posted by Varyon View Post
However, another problem (ugh) I've run into is an extension of the interdiction concept from my previous post. As it stands, the best way to deal with an incoming fleet of fighters is to send out a single tiny missile as soon as you detect them. You'll drop their pseudovelocity to null, giving you ample time to escape. The counter to this would be for the fighters to carry a bunch of antimissile missiles so they can stop the missiles using the same trick, then skirt the perimeter of the missile's combat range to keep up their velocity. This could easily devolve into massive swarms of missiles on either side, and I don't want that.
This might not fit your fluff, or the aesthetics of how you imagine space fights, but maybe you could solve this by having combat/travel space instead of combat/travel speed; i.e., the energy fields projected by the drive create "bubbles" of inflated space. If they measure 5,000 km on the outside, the inside could be merely 5 km. If two bubbles join, the fighting inside takes place at WWII speeds and ranges, but to outside observers, they still appear to be moving at their travel velocities. A missile encountering a fighter squadron takes 10 seconds to clear their bubble either way: inside, it moves at 500 m/s and covers a 5 km; outside, it appears to move at 500 km/s and covers 5,000 km. The fighters can still shoot it down, and do it with WWII dogfighting, but the "interdiction" doesn't result in both them and the missile slamming the brakes and losing all of their space velocity.

However, aside from begging the question "how does it all look? Do the ships and people suddenly look gigantic when observed from the outside? Is it all obscured by a shimmery void?", this solution also requires that everything happening in combat-space correlates to real-space by a factor of X, which is limiting.

Quote:
Originally Posted by Varyon View Post
While it's Space Opera, the setting is meant to take place in the future, not an alternate reality or a long time ago in a galaxy far away. There has been some tech regression, but not to the extent of getting rid of computers. The setting, of course, still needs a bit of work, but as it stands it could probably be described as "safe-tech, minus nuclear energy, plus cybernetics and neural interfaces."
That's not that strange, provided you justify it. I've seen some very recent and very hard sci-fi where computing is near-singularity (which, should you put your setting ~500 years in the future, is somewhat expected and needs to be consciously nerfed if unwanted), but has been crippled or rendered unusable by some outside force. In the case of Alastair Reynolds' Chasm City, you have a superadvanced society that made everything from toothpicks to buildings out of nanomachines, and almost went extinct with the appearance of the "Melding Plague," an infection that makes nanomachines go haywire. They survived by regressing to a form of technology crude enough that the Plague couldn't infect it, or by sealing themselves into clunky hazmat suits for life. Similarly, the only reason the new Battlestar Galactica survives the cylon ambush is because it was all analogue and lacked networked computers, since it's a relic from the previous war, where cylons disabled ships via computer viruses.
Seneschal is offline   Reply With Quote
Old 12-08-2014, 12:51 PM   #19
Varyon
 
Join Date: Jun 2013
Default Re: Space Opera Semi-Psuedovelocity Drives

Quote:
Originally Posted by Zeta Blaze View Post
What happens when a ship mounts
a Semi-Reactionless and a Reactionless drive?
This is what space transports (ships between fighter and capital ship; think Millennium Falcon) do - reactionless works better for very short distances (and combat, if it comes to that), but semi-reactionless is much better for long distances. You simply use the one that matches the current mission best.

Quote:
Originally Posted by Zeta Blaze View Post
What happens if you turn both on at the same time?
In theory, you'd handle the pseudovelocity gained from each separately - when a space transport is interdicted by a small (that is, not large enough to interdict the reactionless drive) fighter, you could have a case where the transport's semi-reactionless drive is interdicted, eliminating any pseudovelocity that came from it, but the reactionless drive isn't.
In practice, they'd probably get hit by the largest book I had at hand.

Quote:
Originally Posted by Seneschal View Post
This might not fit your fluff, or the aesthetics of how you imagine space fights, but maybe you could solve this by having combat/travel space instead of combat/travel speed; i.e., the energy fields projected by the drive create "bubbles" of inflated space.
Doesn't fit, requires too much superscience, and is way too complicated. I'm not saying it's necessarily a bad idea, but I think it would end up causing headaches.

...

I've actually decided it's probably going to work out best if I make the drives into essentially boost drives (fluff-wise, they actually just have such high acceleration they can reach top speed in a fraction of a second). Otherwise, the tactical implications of interdicting a squadron of fighters basically mean that unless you manage to approach your target from directly in front of it, it can reliably escape you via interdiction - and I most certainly do not like this. This is going to require a total rehashing of the way they work, unfortunately.

After a lot of work and thought, here's how I intend to have it work out. Both reactionless and semi-reactionless have two modes - travel and combat. Travel with reactionless has a top speed of 1000 mps per drive, which requires 90 PP per drive. Efficiency can be increased up to 5-fold by decreasing speed by the same factor, for a cruising speed of 200 mps per drive, requiring only 3.6 PP per drive. In-between speeds use in-between efficiencies - divide needed PP by the square of the reduction factor. Semi-reactionless is similar - top speed is 200 mps per drive and burns through 0.75 PP per drive, and cruising speed is 40 mps per drive and burns through 0.03 PP per drive. For every PPh of energy used, 1% of a fuel tank of hydrogen is expelled as reaction mass. If the vessel experiences a collision while moving at travel speeds (with pseudovelocity), treat it as though it had an actual velocity in yards per second equal to mps/20 (that is, at 1000 mps treat it as though it were moving at Move 50; and 40 mps, as though it were moving at Move 2).

Things are simpler in combat - there's no change in efficiency. Rather, reactionless drives have Move 10/50 per drive and require 18 PP per drive, while semi-reactionless drives have Move 2/10 per drive and require 0.15 PP per drive (again, every PPh of energy corresponds to 1% of a fuel tank of hydrogen).

Transferring between travel and combat speeds is handled via the interdiction scheme I outlined in previous posts. Use the vessel's collision velocity to determine what speed it starts out at (so a 4-drive fighter cruising at 800 mps starts at Move 40, a 10-drive missile going all out at 10,000 mps starts at Move 500, a 2-drive carrier moving at 40 mps starts at Move 2, and so forth).

Quote:
Originally Posted by Seneschal View Post
That's not that strange, provided you justify it.
Lack of nuclear energy and genetic engineering is mostly the result of fear-mongering and a bit of history. For the first, many of the original colonists weren't very pronuclear to start with, and they got really paranoid and thought Earth had destroyed itself (with nukes, naturally) when they lost contact for a few decades early in the journey. Earth eventually reestablished contact, but was now under new management (due in part to a partial nuclear war) and demanded the fleet do the unthinkable and turn around, abandoning their colonization effort. Most of the colonists refused, but one of the generation ships decided* to turn around after all, and its crew tried to convince the others to do the same. Not wanting to turn around, a pilot from one of the other ships loaded up his own ship (which was used for mining asteroids and the like for raw materials) with a nuke and flew it into the "traitor," destroying both. Having lost an eighth of their potential population, it's no real surprise they gained such an aversion. For genetic engineering, there was already quite a movement against the practice on Earth (and thus within the original colonists), and the spacers are either opposed to it on religious grounds or due to fear of "unmaking" the human race and replacing it with something else.

As for general lack of AI, I personally don't see intelligent/sapient/whatever AI as inevitable, so that combined with a bit of fear of it is enough to keep it at bay. Probably the most advanced AI available serves to control weapon turrets - which legally can only be equipped with ion cannons (which disrupt electronics without blowing up ships) and can typically only be used in space (as in atmosphere disabling an aircraft is likely to result in a fatal crash).

*History is conflicted here; the above is the version put forth by the Earth Caliphate, its allies, and some of the secular nations. Some of the other nations tell a very different story, of a hijacked generation ship trying to ram the rest of the fleet and a brave pilot sacrificing himself by crashing into the ship's fusion plant. Most aren't certain which is true.

Last edited by Varyon; 12-09-2014 at 08:03 AM. Reason: changed some numbers to line up a bit better
Varyon is online now   Reply With Quote
Reply

Tags
pseudovelocity, pseudovelocity drives, space opera, spaceships

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Fnords are Off
[IMG] code is Off
HTML code is Off

Forum Jump


All times are GMT -6. The time now is 06:07 AM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2024, vBulletin Solutions, Inc.