DrTemp

Re: Further thoughts about the UES Centauri and the AW space combat environment I see. That allows for battles at much longer ranges than I anticipated, but I still believe that due to the limited delta-v available even with fusion rockets, the defender's usual tactics should be to wait in orbit and welcome the intruding fleet from there. What is a "vacuum booster"? I thought about the fighters, though- in a widely spread formation, they are more capable to withstand a space nuke as a squadron than a larger spaceship the cost of a aquadron is. Fighters would have to be built with a similar fusion drive as the larger ships, though- and maybe about the same delta-v. _If_ one assumes that those fusion drives can be built in such a light way that high-thrust-fusion drives are possible, that is.

Re: Things that are cool about Alien Wars

Re: Further thoughts about the UES Centauri and the AW space combat environment Well, in the case of AW, this seems to be rather unintentional. It obviously tries to be hard science where that is applicable. Do you have a name or link on that? That'd be cool. Well, encounters usually start at a minimum of 100 000 km. Effective weapon range is about 3000 to 5000 km (or is it?). There's a lot of maneuvering one could do to avoid an opponent whose delta-v is a bit scarce... Hm- I'm thinking about the role of space fighters in such an environment. Do they make sense?

Re: Further thoughts about the UES Centauri and the AW space combat environment The available hydrogen in space is not that much, though. And that scoop would have to be very big. Star Hero mentions those Bussard ramjets and what their problems are on page 190.

Re: Further thoughts about the UES Centauri and the AW space combat environment

Re: Something Star Hero needs, but hasn't-PT2 Next thing you tell me is that there are other SF settings out there that I could buy.

Re: Something Star Hero needs, but hasn't-PT2

Re: Things that are cool about Alien Wars Well, those technical problems don't seem to be unsolvable by principle: http://repairfaq.ece.drexel.edu/sam/laserioi.htm#ioixrl

Re: Things that are cool about Alien Wars

Re: Average Seperation You'll probably find tons of info about that on the 'net. One thing, though: the as-yet-detected planets are almost all of the gas giant variety. AFAIK, only one "terrestrial planet" (which means "a ball of rock") could be located, and they're not sure whether it is that or just a very small gas giant. The problem with detecting extraterrestrial planets with curent technology is that one cannot spot them directly with a tetelscope or something- they simply look at the star and try to see when it is dragged a tiny bit towards a direction were it douldn't be dragged, thus assuming that there must be some planetary body whose gravity well draws thestars towards them. The exact size of that (_very_...) tiny bit tells the astronomers how large and heavy the planet is. Humanity will need a lot better telescopes for directly spotting extraterrestrial planets.

Well, I could not resist to think more about the Centauri's propellant problem. First, I thought "Okay, it is flight, not cumulative flight, so they'll probably just spend lots of time in free fall." Space battles thus wouldn't be too exciting, but at least it could work, I thought. However, they want to be in orbit around an Earth-sized planet and want to make Hyperjumps from there. The Hyperdrive requires "a distance of about a hundred thousand kilometers" from an Earth-sized world, which means essentially leaving orbit. But to do that, one needs escape velocity- 11.2 kilometers per second. The Centauri with chemical rockets, however, could not hope to carry anything but propellant and manage to reach that speed at the same time. So the obvious solution is another drive, probably a thermal fusion rocket. I am a bit optimistic, so I assume this one has an impulse of about 100 000 seconds, or an exhaust velocity of a about 1 000 000 m/s. That way, our battleship could use only one-third of its 100 ktons of mass as propellant (leaving about 65 000 tons to the actual ship) to have a delta-v of 20% of its exhaust velocity, which means a delta-v of 400 000 m/s or 400 km/s. If it burns all the propellant, which it won't, of course. (100 ktons initial mass divided by 65 ktons final mass is about 1.5, ln of 1.5 is 0.4) This "new and improved" Centauri could accelerate to escape velocity and a bit more, say, 20 km/s, proceed in free-fall to the jump point 100 000 km away (which takes it 5000 seconds, or just below one and a half hours), then jump, decellerate if necessary, accellerate into the other direction again to reach a close orbit, decellerate again, and fight its way through enemy ships. It would then have used up about 20% of its propellant. That's probably as good as it gets with hard SF assumptions. Since we know that Xenovore ships are not far superior to Terran ships, this is probably also close to the technical limits of their dreadnoughts as well. Now what would that imply for ship combat tactics? Most of the time, one fleet will jump into the system, then accelerate (having decelerated before the jump) towards the target planet, where the defending fleet waits in orbit. Detection is absolutely no problem for both sides, since the energy required to power such large ships will be detectable pretty easily via infrared. Intercepting the incoming fleet would not be smart, because that would mean to burn lots of delta-v to get some velocity, then decelerate (with the drive pointing towards the enemy, and no, no Kzinti lesson is applicable here) to match enemy's velocity about the time when the fleets meet each other in space and "escort" the attacking fleet back- if your ships are still in fighting condition after the decelleration maneuver, which the enemy would doubtlessly use to attack you while you can't shoot back accordingly. The defending fleet might manuver a little in orbit, but given the available acceleration rates and delta-v, they won't be able to "evade" any attacks. That means the two fleets will be mindlessly shooting each other, since outmaneuvering is simply impossible. Space combat will thus be a rather boring "who hits most first" excercise. Is this true, or did I overlook anything?

Re: Things that are cool about Alien Wars IIRC, those rifles were Xray-Lasers. So smoke is not that much a problem.

Re: Things that are cool about Alien Wars Well, the setting knows "cold fusion reactors". So not much shielding required.

Well, while there is this certain problem with the setting I mentioned earlier , there are lots of cool things about the setting. One thing I just wanted to point out: Laser rifles. Now there is a real reason why a modern army should have those. The Laser rifle is a large military's wet dream: While it is not as efficient as a conventional slugthrower, its ammo ist just a few hundered thousand times easier to obtain. That was an idea I had never encountered before, at least not for infantry weapons and it is the most plausible reason for using personal energy weapons I have seen. Just reread that part and felt the urge to say that. Thank you for your attention, citizen.

Re: Something Star Hero needs, but hasn't-PT2 True, but 1) Terran Empire an Alien Wars would really profit from a deck plan book as proposed (setting-feeling-wise) 2) there's probably "a lot" (as far as SF RPG's are concerned...) of money-earning potential in such a product, because while one can use foreign setting deck plans with AW and TE, the other way round this is also true. Plus, the ships from Jovian Chronicles are virtually the only ones with deck plans and spin gravtiy AFAIK... and there are not that many deck plans of them UES Centauri and UES Jupiter deck plans, now!

Re: Usning nanotech in a campaign Well, not too much. You'd have to give your nanobots lots of energy to force the gas molecules together. It'd be much cheaper and simpler to cool the gas. Nanotech is not an all-powerfull super tool, it would probably not even be very competititve against more conventional means for many tasks, such as metalworking. It cannot change he laws of physics, either.

Re: Something Star Hero needs, but hasn't. If you have a reactionless thruster (such as in later TE times), you can accelerate all the time. Now, if your Hyperspace drive works as described in AW und TE, you will accelerate in Hyperspace also (only 1 m/s in Hyperspace will equal 1 000 000 m/s in normalspace). T is the Time required (in seconds), V is the average velocity (in megameters per second), A your acceleration (in m/s/s) T= D/V V= A*T/4 So your travel time is: T= D/(0.25*AT) D=0.25*A*T^2 4D/A=T^2 T= [4*(D/A)]^(0.5) or T=2*[(D/A)^(0.5)] Thus, the travel time is not proportional to the distance. A twice as high a distance requires not twice as much travel time, but less. To most people, that does not feel right, and it requires computation that most people aren't used to.

Re: Alien Wars: Before hyperdrive, there was...

Re: Something Star Hero needs, but hasn't. D'oh! Of course! Still, with all the work put into the existing stats in AW, TE and SpT, I would prefer simply changing the rubber science explanation to "shunt into another universe which moves (maybe: "rotates"?) at superluminal speeds relative to our own, stay there for a while being dragged, then return when desired". Higher class hyperdrives would allow to shunt into even faster hyperspace universes. (If you like the idea, feel free to use it at no cost. ) After all, using quadratic equations for all interstellar travel could really bog down a game... and the effect of larger distances being not as far away in travel time as is showed in distance on the map is rather un-intuitive.

Re: Alien Wars: Before hyperdrive, there was... Well, it could have been a drive that was of very high impulse, but very low thrust, allowing for accelerations of 0.01 g (0.1 m/s^2) or even less, but for a very long time with a given propellant mass. That would make it useless for tactical or short-term operations, but quite valuable for interstellar travel at STL speeds.

Re: Alien Wars: Before hyperdrive, there was... That's not correct. There was at least Earth. Suggestion: The Colony Act was actually some kind of political maneuver to achieve some completely different, more day-to-day buisiness-like thing which is now long forgotten. "By accident", it was also a document that allowed for the legal concept of "more than one Senate world", because until then, there was only one world allowed to send senators, and that was Earth, of course. (For example, the real idea behind the Colony Act and a few related documents that in effect changed the UE's constitution could have been to install a new office: That of Earth's senator, who would have been quite powerful given the fact that he was the only one...no one of those who passed the Colony Act really believed that there could ever be a real "Senate" with many Senators.)

Re: Something Star Hero needs, but hasn't. But it doesn't do that. You cannot "build" a starship with Hero System. You can only *describe* its abilities in game terms and assign a point cost (which is usually rather useless for a spaceship in a campaign where these are regularily bought and sold).

Re: Something Star Hero needs, but hasn't. Yes, I noticed that too. I decided for myself that the rubber science explanation of hyperspace and the Hyperdrive are wrong, and the stats for the hyperdrives given are correct- both is not possible. OTOH, since the stats for the ships giving would need a rework in the light of what has been shown, maybe one could correct this too in the 2010 "revised edition" of Alien Wars... I believe for actually mapping the described hyperspace physics one would have to buy the Hyperdrive not as Teleportation, but as normal movement plus Megascale and ignore "not for FTL" rule on that. The STL drive would have to be another one- possibly an antimatter drive of some kind, or maybe a "particle accelerator neutrino drive" (which would have the convenience of not being a _very_ potent weapon, since neutrinos are harmelss particles). Now that's maybe actually an idea: Building a particle acclerator of high output, powering it with a fusion reactor, and using it as a drive. Based on current technology, it would be very low-thrust, of course, but advanced versions might become better at that too. The impulse would be near light speed. Of course, one would have to miniaturize particle accelerator technology, but that is not completely unthinkable... Edit: Oops. I just reinvented the ion drive. Sorry

Re: Something Star Hero needs, but hasn't. But that's TV, and thus a different medium. RPG as a medium of storytelling is a different thing and has different requirements, since it has not the all-powerful author to make the epsisode work. Players of an RPG need some base for their imagination and planning. If they have to solve the problem of aquiring, for example, enough propellant for their spaceship to reach starbase X, they need some background about "what" and "how much" of it. With said Centauri, they'd run into a problem here... a problem that could blow up the entire gaming session if the group cares for such details (and they play hard military SF, so they probably do). In SF, you have lots of equipment, but the story should be the story of the characters. In order to give them something to act, you have to give them a coordinate system to act within. Besides, there are not that many attempts to make a hard sf TV show, so we have no choice but live with those that are there, even while being annoyed by a lot of details. The new Battlestar Galactica series seems to be the first attempt on hard SF TV. And it is really an order of magnitude better than the others... Actually, the known-science-parts of the Traveller constructon systems (hull masses, for example) are quite universal. The differences between settings lies in the rubber science parts. As long as the setting in question is well-thought through, of course. There is lots of bad SF out there, where the technological and super-scientific assumptions don't make sense within themselves at all.

Re: Alien Wars: Before hyperdrive, there was... There ain't no such thing as a free lunch. How can this be for the former? The latter, okay, sure. But simply redirecting the pions should not require any additional propellant? That is something a revolutionary energy source like fusion power, combined with new, better techniques of producing antimatter and a reason to do so on a large scale could actually do.