 December 15, 2010 - 4:35pm | I was reading the Knight Hawks expanded rules, and I noticed that it states clearly that the chem drives cannot accomplish an interstellar jump and that the atomic drives can. However, it does not say if ion drives can. I did the math and, according to the rules (where jump speed is 12,000,000 kilometers and the ion engines accelerate 10,000 km (1 hex) a turn) and ion drives could attain jump speed with a little over 1000 units of hydrogen (with a max load of 10,000 units in all of the engines). Could they be allowed to jump, jump with a penalty to misjump (due to a less exact acceleration, less rapid deceleration, etc.), or what? Thoughts? |
 December 15, 2010 - 4:43pm | The short answer is yes, ion drives should be able to achieve jump speed and I believe that most of the people here allow them to do so in their campaigns. There is a longer answer that involves the issues of ADF verses 1 g acceleration and such but I'm not going to start that again. It has been rehashed a few times already.  Ad Astra Per Ardua! My blog - Expanding Frontier Webmaster - The Star Frontiers Network & this site Founding Editor - The Frontier Explorer Magazine Managing Editor - The Star Frontiersman Magazine |
 December 15, 2010 - 5:06pm | See page 4 of the KH expansion rules under spaceship types. In the part on system ships it say no chemical engined ship can achieve interstellar jump. In the section that talks about starships the first paragraph it mentions that starships are driven by atomic or ion engines and can make interstellar jumps. Not is so few words but it is there about all the engines that can or cannot make a jump. |
 December 16, 2010 - 6:10pm | Technically (since a chem drive's ADF is "always 1"...same as Ion drives), given enough fuel a chem drive could reach jump velocity. It would have to be an insane amount of fuel though. Even by my rehashed chem drive rules, the ship would literally be little more than an engine with a huge fuel tank (and once jump velocity is reached, it requires the same amount of fuel to slow it back down again). Long story made short, it's possible but not feasible...there just wouldn't be enough room for anything else on the ship. You'd need a bigger hull, and bigger hulls mandate more/larger drives that gulp more fuel...  Another technicality (going by what's in the rulebooks anyways) --- jump speed can be attained at ADF:1 in 200 turns (12M kph = 1200 hexes per hour = 200 hexes per ten minute game turn), thus using only 200 units of L-Hyd per ion drive to reach jump velocity (and another 200/drive at the other end to decelerate back down to zero). IIRC the ADF to G conversion is something like 3G per 1 ADF. |
 December 17, 2010 - 6:24am | Has anyone done any research on the "Slingshot Effect"? I wonder how much speed could be gained by swinging out of a gravity well, either terrestrial or stellar. Is this something that in the SF tech-level, would be possible? Thanks! You can't argue with the invincibly ignorant. - William F. Buckley |
 December 17, 2010 - 10:32pm | Contemporary spacecraft do gravity-assists(slingshots)as a matter of course. The gravity serves to magnify the effects of the main engine burn, by a factor entirely dependent on the angle of approach and how deep in the gravity well you go, amongst other things. Wikipedia has all the math and stuff for this here: " 'Beware the Beast, Man, for he is the Devil's pawn. Alone among God's primates, he kills for sport, for lust, for greed. Yea, he will murder his brother to possess his brother's land. Let him not breed in great numbers, for he will make a desert of his home and yours. Shun him; drive him back into his jungle lair, for he is the harbinger of death." |
December 18, 2010 - 1:30pm | It could probably be boiled down to something like 1.5 times the current speed (or smaller) multiplied by the gravity of the planet, e.g. 10 hexes x 1.5 x 1 (using Earth)= 15 hexes per turn. The effect would prob be the result of not using MR to alter the gravity well effect explained in KH advanced rules. 1.5 might be a bit large, but I don't have the time right now to read up on the science. |
 December 18, 2010 - 6:36pm | Hang on a minute and let me get my Astro-Physics PhD dusted off. Oh wait I don't have one. Once again realism versus playability. If you want them to work then stick with a simple rule and don't go a changing. Otherwise ruleslawyers will destroy your game sessions. Oh and try to explain the house rules ahead of time so there are no surprises. Sounds like a great job but where did you say we had to go? |
December 19, 2010 - 3:52am | TerlObar's astro-physics PhD has been free of dust for some time. Paging Mister Obar, Mr. Terl Obar, you have a call waiting on the red phone... |
December 19, 2010 - 10:48am | And, even on the white courtesy phone. " 'Beware the Beast, Man, for he is the Devil's pawn. Alone among God's primates, he kills for sport, for lust, for greed. Yea, he will murder his brother to possess his brother's land. Let him not breed in great numbers, for he will make a desert of his home and yours. Shun him; drive him back into his jungle lair, for he is the harbinger of death." |
December 19, 2010 - 3:37pm | But I haven't done classical mechanics since my undergraduate days. After a decade and a half that part is a little dusty. I'll take a look and see what I can come up with, but it will at least have to wait until Issue 16 of the Star Frontiersman and episode 5 of the Whispers from the Void podcast are done. (I just need to do the choose your own adventure segment and piece it all together for the latter.) Ad Astra Per Ardua! My blog - Expanding Frontier Webmaster - The Star Frontiers Network & this site Founding Editor - The Frontier Explorer Magazine Managing Editor - The Star Frontiersman Magazine |
December 20, 2010 - 2:13am | And, even on the white courtesy phone. This kinda reminds me of the opening score on Airplane...to paraphrase: "The red phones are for emegency use only. Please do not use the red phones unless you have an emergency." "The white phones are for customer courtesy use. Anyone may use the white phones." "The red phones are for emegency use only. Please do not use the red phones unless you have an emergency." "The white phones are for customer courtesy use. Anyone may use the white phones." "The red phones are for emegency use only. Please do not use the red phones unless you have an emergency." "The white phones are for emegency use only. Please do not use the white phones unless you have an emergency." "No...the RED phones are for emegency use only. The WHITE phones are for customer courtesy. Please do not use the red phones unless you have an emergency." "Okay, Will...I can tell that it's going to be one of those days. The white phones are for customer courtesy use only. Please do not use the white phones unless you have a customer courtesy emergency." "Look, Richard...I'm not in the mood for your crap today. It's time we settle this on the green phones!" |
 December 20, 2010 - 3:22am | Based on what the rulebook stats, it always seemed like only atomic-powered ships can achieve Jump, as Ion-burners movie too slowly (being less then 1 hex/turn, but they rounded it up), and rockets require way too much fuel to the point where most of the ship is a big fuel tank (how much fuel would one have to burn to equal 10cm of an uranium rod?). Ideally, I would allow fuel-burners to move past 1 A/D, but at the cost of range. This would make them good for fighters, shuttles, and missiles (this would make Fighters even more bound to their Carriers and alot more cheaper), but lager long-range ships would use Ions if cost was an issue. By the way, if ships suck-out the air before a fight - or blow it out at any time if need be - then why do they have Electrical Fires? If anything, a ship with an atom-cooker should have "Nuclear Meltdown" (same effect, but with radiation trying to flooded the ship) instead, as it would make more sense, and fuel-burners would have "fuel tank explosion" (this is more of a burning fuel leak than anything) that would do damage only once, as well as lower the ship's range by half per failed repair phase (Ion Engines have nothing that harmful to cook-off). |
December 20, 2010 - 5:49am | Engine Upgrade Tachyon Drives An update to the older Ion Drive engines, these emit a stream of FTL particles that impart a better ADF/MR of than those of the particles used by the Ion Drives. While still not as powerful as Atomic or Pion drives, these can give your old Ion freighter a new life. Ships equipped with Tachyon Drives have an ADF/MR of 2, doubling the oomph of Ion drives, and allowing the ship to reach jump speed in half the time. While they use the same fuel as Ion drives, they can only store half as much per engine, and are unable to use "junk" as fuel. These are available in all sizes, A, B or C, and cost 50% more than their Ion counterparts. Here at Crazy K'nort's, we'll give you a 20% discount if you trade-in your old Ion engines and install the new engines at 50% of the normal fee! We're not cheap, WE'RE CRAZY! You can't argue with the invincibly ignorant. - William F. Buckley |
 December 20, 2010 - 10:23am | Fuzzy Science Alert (Those sensitive to Fuzzy science concepts should proceed with caution, as nausea, headaches, and other effects have been linked to Fuzzy Science exposure) Funny you should mention Tachyon Drives, because in my Star Frontier's rules set Tachyon Drives are what ships use to travel at faster than light speeds. Ships are equiped with sublight engines (there are several types beside chemical, Atomic, and Ion) with most ships using ion/repulsor lift engines (as ion, and radiation spewing ships are restricted from atmospheric flight), ships switch to thrusters when entering a planetary atmosphere. Anyway a ship's faster than light drives generate a tachyon field around the ship which allows them to slip past the light speed barrier, and accelerate to hyper light speeds, traveling one or more light years/day depending on the class of hyperdrive they possess. The older Tachyon drives did not allow communication (sublight radios) while a ship was in hyper space, but newer tachyon drives no longer have this problem. Because the rules set deals with an alternate reality Frontier (set about 100 years in the future of the Frontier if you compare the two time lines) ion drives allow a ship to accellerate/decellerate by 3 Au/hour or cruise at 6au/hour. and yes I do have artificial gravity in my game. "Hey guys I wonder what this does"-Famous last words "Hey guys, I think it's friendly." -Famous last words "You go on ahead, I'll catch up." -Famous last words "Did you here that?" -Famous last words |
 December 20, 2010 - 12:10pm | I've been in favor of an atomic A size drive on a fighter and a chemical drive with extremely limited fuel (3-5) fighter uses the atomic drive at all times and has normal ADF/MR based on that but at anytime while moving the pilot may opt for "thrusters" and burn of a unit of fuel in the chemcial rocket for 1 extra point of acceleration/ turn. Sort of an old school BSG colonial viper. I might not be a dralasite, vrusk or yazirian but I do play one in Star Frontiers! |
December 20, 2010 - 1:30pm | If anyone needs an official ruling about ion drives and void travel, direct your attention to page 5 of the KH Campaign Manual --- the Minelayer description: |
December 20, 2010 - 1:24pm | I've oft thought about that as well, Jedi. If fighters are planet-based, and Atomic Engines generate large amounts of deadly radiation, wouldn't it be bad for them to use that engine to get into the fray? Chemical engines would most definitely (IMO) be not only a plus, but necessary to the design and functionality of a fighter. In otherwords, yea, I agree with you on your point. =) You can't argue with the invincibly ignorant. - William F. Buckley |
December 20, 2010 - 3:32pm | New crewman: Sir, what are these chemical boosters for? Crewchief: They are to assist fighters to get into orbit so that the atomic engines will not radiate the planet when they launch. New crewman: Thats a good idea. Crewchief: Son you scare me sometimes. New Crewman: Why? Crewchief: I wonder if you went through the correct tech school for this job. I think that says it all. |
December 20, 2010 - 5:51pm | I thought the rules address the issue of atomic drives- that upto HS 5 could launch from planets but that only atomic drives size A (HS3) were permitted to do that. the only other issue was that ion drive could not launch from a planet at all. I might not be a dralasite, vrusk or yazirian but I do play one in Star Frontiers! |
December 21, 2010 - 3:12am | KH Campaign Book page 9 (Spaceship Construction) says "starships larger than hull size 3 are not streamlined to land on planets". And size doesn't make a difference here. According to the hull specification chart, a HS:4 system ship has one A-size chemical thruster while the three atomic B drives of a starship don't produce enough power for the same job? Yeah, that's what I'm getting at... |
 December 28, 2010 - 12:31am | Bump Bump ... Agree with Shadow on this point. And by the way the radiation from a fission bomb was never as bad as they made it out to be (they were trying to scare the Soviets).. If it was, the tours of Trinity Site would kill all the tourists. Also I dont think the thrust from an engine would release nearly the amount of radiation that the bomb does. Just my humble opinion The bombing starts in five minutes. |
December 28, 2010 - 2:00pm | An atomic engined ship would still doubtless require a hardened site to take off from, to minimize the area being slagged, but, otherwise, it can take off from pretty much anywhere on a planet, as long as it's streamlined. Possibly even if it's big and unstreamlined, though not without damage and/or risk of breaking up in atmo. " 'Beware the Beast, Man, for he is the Devil's pawn. Alone among God's primates, he kills for sport, for lust, for greed. Yea, he will murder his brother to possess his brother's land. Let him not breed in great numbers, for he will make a desert of his home and yours. Shun him; drive him back into his jungle lair, for he is the harbinger of death." |
December 28, 2010 - 2:55pm | I'm of the arguement that the thrust from an atomic drive is not toxic or deadly. It's like a nuclear power plant, the electricity that arrives at your house isn't toxic or deadly...same principal. Either way, you don't want to be around the source when things go awry. And that's where the legality issues pop up, I could easily see planetary governments not wanting atomic thrusters zipping in and out of their atmosphere. But in no way does that translate to the ship not being capable of doing so. |
December 28, 2010 - 3:46pm | I'm of the arguement that the thrust from an atomic drive is not toxic or deadly. It's like a nuclear power plant, the electricity that arrives at your house isn't toxic or deadly...same principal. Weell, I wouldn't say the house current isn't deadly...anyone fool enough to stick his fingers between the prongs of a plug and an electrical outlet might be in for the shock of his life. Not to mention the fact that the voltage going through the lines before it reaches the residential step-down transformer will fry you a nice-a golden brown. I see what you're saying, though. Safely handled and properly maintained, an atomic drive is as unlikely to leak radiation as a nuclear power reactor. The exhaust from an atomic drive, on the other hand, while not toxic, will be hot(with heat/There is some s* I will not eat....), as a certain hover-bike ganger turned pilot can attest to.... " 'Beware the Beast, Man, for he is the Devil's pawn. Alone among God's primates, he kills for sport, for lust, for greed. Yea, he will murder his brother to possess his brother's land. Let him not breed in great numbers, for he will make a desert of his home and yours. Shun him; drive him back into his jungle lair, for he is the harbinger of death." |
December 28, 2010 - 3:51pm | I'm of the arguement that the thrust from an atomic drive is not toxic or deadly. It's like a nuclear power plant, the electricity that arrives at your house isn't toxic or deadly...same principal. Either way, you don't want to be around the source when things go awry. And that's where the legality issues pop up, I could easily see planetary governments not wanting atomic thrusters zipping in and out of their atmosphere. But in no way does that translate to the ship not being capable of doing so. perhaps the prohibition stems form the early days of the UPF when a new class of frigate experienced an number of lift off problems stemming, in reality from a poorly designed/streamlined hull, but blamed on the atomic engines during the Warren Commission, that was impanelled to investigate the accidents (in one case a ship crashed and the scrambled computer files self destructed the engines close to a settlement) thus the rule against it is based on legistlation not any inability of the atomic engine to lift a HS5 ship from a planet. I might not be a dralasite, vrusk or yazirian but I do play one in Star Frontiers! |
December 28, 2010 - 3:54pm | In other words, the prohibition is a reaction to a single incident and isn't based on anything concrete. Hmmm, an adventure investigating the cause of the original accident, uncovering more than what the PCs bargained for. " 'Beware the Beast, Man, for he is the Devil's pawn. Alone among God's primates, he kills for sport, for lust, for greed. Yea, he will murder his brother to possess his brother's land. Let him not breed in great numbers, for he will make a desert of his home and yours. Shun him; drive him back into his jungle lair, for he is the harbinger of death." |
December 28, 2010 - 4:00pm | In other words, the prohibition is a reaction to a single incident and isn't based on anything concrete. Hmmm, an adventure investigating the cause of the original accident, uncovering more than what the PCs bargained for. Noooo, it would be several incidents but the nucelar blast that destroyed a settlement would have been the biggest and most famous. In fact it could have been the venerable UPF frigate, all of which remain in space now. I might not be a dralasite, vrusk or yazirian but I do play one in Star Frontiers! |
December 28, 2010 - 5:00pm | Personally in my own campaign I have always allowed ships of hull size 5 or smaller to land on world, but while atomic and ion engine type ships can not land on planet with those engines, ion engine ships can be fitted with planetary thrusters. These thrusters are based on the same technology as hover vehicles and allow a ship to move within a planetary atmosphere at speeds up to escape velocity. The size of the thrusters are included in the cost of the ion engine. The thrusters are hooked to the ship's powerplant and use about 1/10th the power of an ion engine. The ship does not lose its MR rating while on world but its speed is limited to escape velocity. Atomic engines can have thrusters, but it is illegal for them to enter a planetary atmosphere, however some outlaw technicians have been known to build mock shells which cost about 10,000cr/hull size which will make an atomic engine look like an ion engine with only a 5% chance/level of the engineer to detect the truth opon casual inspection. Oh and thrusters use a level one (3 function point) drive program. "Hey guys I wonder what this does"-Famous last words "Hey guys, I think it's friendly." -Famous last words "You go on ahead, I'll catch up." -Famous last words "Did you here that?" -Famous last words |
December 29, 2010 - 12:40am | In other words, the prohibition is a reaction to a single incident and isn't based on anything concrete. Hmmm, an adventure investigating the cause of the original accident, uncovering more than what the PCs bargained for. Noooo, it would be several incidents but the nucelar blast that destroyed a settlement would have been the biggest and most famous. In fact it could have been the venerable UPF frigate, all of which remain in space now. Oh, okay. " 'Beware the Beast, Man, for he is the Devil's pawn. Alone among God's primates, he kills for sport, for lust, for greed. Yea, he will murder his brother to possess his brother's land. Let him not breed in great numbers, for he will make a desert of his home and yours. Shun him; drive him back into his jungle lair, for he is the harbinger of death." |
