GoSlash27

Archgeek, I can't say I've ever gotten a rescue contract for a Kerbal on a collision course. *shrug* I'm not saying that excessively high DV is utterly useless... just sayin' I've never found a use for it in stock. Best, -Slashy

Tweeker, ^ see above. If you think .5G is asking too much, then you can always pick a different limit. The important part is to have one and compare engines that are actually doing the same job, not different ones. Best, -Slashy

Tweeker, Sorry, but that's how stages are designed; "Accelerate x payload at a minimum t/w of y for a total of z m/sec DV". Each job description is unique, and the ideal engine varies with the application. For 2 km/sec DV, 9.46t payload, and minimum t/w of .5, they stack up like this: Nerv: 21.3t, $21,650 Terrier: 22.2t, $3,930 Poodle: 23.5t, $3,700 The Nerv starts becoming competitive at higher DV, and the Poodle becomes dominant with larger payloads. Best, -Slashy

Archgeek, I'm talking about stock KSP, specifically career. Best, -Slashy

I think the problem with the Dawn is that it's scaled all wrong for the KSP solar system. There simply isn't a need for the kind of DV numbers it provides, and by the time it can out- perform the NERV or chemical vacuum engines, it's t/w is too low to be convenient. Plus, it's way too expensive. It's a solution in search of a problem in stock KSP. I'm sure it fares better in RSS or similar modded installations. Best, -Slashy

Tweeker, Oh, I'm well aware. It's just that I rarely need over 2km/sec DV to do what I need to do. Taking advantage of gate orbits greatly lowers the DV cost to the destinations where funds are important. By the time I start using the Nerv in my designs, cost is no longer an issue. Also... your comparison is not a direct one. Different t/w ratios, different DV. To make a direct comparison, you'd need to design both stages to the *same* mission requirement. Also keep in mind that I generally orbit payloads for around $1,000 per tonne, so even in this flawed comparison my launch cost would still be cheaper with the Poodle. As for trading down to the Terrier... I find that having a t/w below .5 can cause headaches with transfer burn timing and cosine losses, so I don't do it. I use the Terrier for lighter payloads. Just like everything else, I use the correct engine for my requirement. Very often, that winds up being the Poodle. Best, -Slashy

Tweeker, In some situations, that is true, while in others it is not. For people who design with lots of DV in mind, the LV-N can be attractive. But as a practical matter, "more DV" isn't actually better once you have enough to do the job. I have found that I rarely need the kind of DV that makes LV-Ns attractive. Best, -Slashy

Tweeker, You'd have to define "better". In stock career, "better" means lighter and cheaper. From 6 to 22 tonnes payload, 2km/sec DV, and .5 t/w (which covers the bulk of vacuum stage work in stock career), there is no better engine than the Poodle. Best, -Slashy

Sacrilege! The Poodle is like Frank's Red Hot; I use that *%&^ on everything!

I've heard a crazy conspiracy theory that the Laythe landings were faked because Laythe doesn't actually exist. I don't understand all the details, but apparently the Mexicans are involved. Best, -Slashy

Wow, I stand corrected! Plus that plane looks pretty Kudos, -Slashy

Sharpy, Not particularly. One of those tanks was the base part for the side stack. By the time I got it all set, I was too lazy to tear it apart just to replace them. Best, -Slashy

Allocthonous, You're missing out. The Twin-Boar is a fantastically cheap and versatile booster, especially when used in parallel with Kickbacks. 140t to orbit for under $100,000. Best, -Slashy

I went with the Dawn (too expensive and complicated and I don't need that much DV), but there are several other engines I never use. -The Rhino is plenty efficient in vacuum, but way too big and powerful for my needs. -The Vector is too expensive. I can find cheaper ways to do the same thing with other engines. - The Thud. It's just not competitive with other engines in it's class. I rarely use the Puff. If it wasn't for shuttle designs and derivatives, I'd probably never use it. Best, -Slashy

ajburges, That result actually doesn't surprise me; Adapters in general aren't very clean. Nevertheless, you can't build a spaceplane that seats 18 and runs on a single RAPIER from Mk.1 parts. I do agree with you on the volumetric efficiency and crazy- low laminar drag of Mk.3. Best, -Slashy

ajburges, If you refer to the drag cubes in the PartDatabase.Cfg, you will see that the Mk.2 cockpit has a lower drag coefficient than the Mk.1; .201 and .232 respectively. This is where the bulk of drag comes from in transsonic and supersonic flight. Moreover, Mk.2 parts have a lower laminar drag to mass than their Mk.1 counterparts. All of this conspires to make Mk.2 airframes *less* draggy than their Mk.1 equivalent, but only when aligned with the airflow. An example of how "slick" Mk.2 can be: 16 Kerbals and a docking port to orbit using just one RAPIER. I think Mk.2 based designs get a bad rap because they are super- draggy when not aligned with the airflow. They are actually an excellent platform for crew shuttles and light cargo when done correctly. Best, -Slashy

My winter project is all done. New engine, bigger cylinder, lots of porting, bigger carb, and taller gearing. She is, as Freezepop would say, "Ready 2 Rokk" My next trick will be a project bike I bought last spring: a 1959 VBA with a crazy hopped-up motor and a sidecar... Best, -Slashy

Speeding Mullet, While Pro SSTO was a fun and difficult challenge, I don't believe it ever had the popularity or longevity to be called "heritage". Here's the most recent thread (which never really got off the ground) And the original Best, -Slashy

I would say that we all know "heritage challenges" when we see them. If there are a lot of badges in people's sigs, it's a safe bet that it should be considered for inclusion on this list. If not, then it's not popular enough to be considered. Aside from that, the current criteria seem to be fine. Perhaps you should freeze the list where it's at for now, and conduct a poll once a month for new entries? Best, -Slashy

IRT the instability problem... I can't see the plane you're talking about (I don't do mods), but if it looks like these 2 previous designs, the problem is that the center of drag is ahead of the center of mass. The Mk2 fuselage makes crazy drag when not aligned with the airflow and there's a lot of it ahead of the wings and mass. It would create a serious pitch instability problem. Best, -Slashy

AeroGav, I didn't download any of them. My install is 100% vanilla, so I can't open them. I can see by the original pic that the tail would be extremely draggy because it's not actually occluded by anything. If he's no longer using that design, please disregard. *EDIT* Nevermind. I just saw the Agathon II. The tail on that design is fine. In his case, he said that he was using the RAPIERs to get to orbit and then the LV-Ns for the rest of the trip. Doing it his way, the LV-Ns aren't worth bringing along. Doing it your way, it's a different story. If the LV-Ns are used exclusively for the trip to Minmus and back (call it 1,800 m/sec total) and have a minimum t/w of 0.5, the math works like this: The LV-N has 60 kN of thrust, so total ship mass per engine is 12.2t. Fuel to make 1,800 m/sec at an Isp of 800s would comprise 20.5% of this mass. Plus tanks to hold it, 23.1%, or 2.81 tonnes. The Nerv is another 3 tonnes and the unused RAPIER another 2 tonnes. So you're looking at 4.39 tonnes of payload (which is airframe, empty tanks from the trip to orbit, and whatever payload) per Nerv. Doing the same math for the RAPIER at t/w= 1 (they tend to be a bit overpowered in orbit) The RAPIER has 180 kN of thrust, so total ship mass per engine is 18.3t. Fuel to make 1,800 m/sec at an Isp of 305s would comprise 45.2% of this mass. Plus tanks to hold it, 50.9%, or 9.31t. The RAPIER adds 2 tonnes. So you're looking at 6.99 tonnes of payload per engine. In this case, the fuel mass savings of the LV-N simply aren't enough to overcome the mass of the engine and the penalty of hauling around an unused RAPIER. Plus, the plane itself must be larger and draggier because it has additional parallel nodes and the additional mass of the LV-Ns, which are cargo at that point. Now... if he does it your way, using the NERVs to achieve orbit as well as make the trip to Minmus and back, then the math flips. Best, -Slashy

Yeah, Landing gear (especially the fixed gear) are still a little wonky, but much better than they were in the initial release. I really can't comment without seeing the aircraft. Best, -Slashy

Gaarst, You should copy the OP to the tutorials section. Valuable info. Best, -Slashy

Whaa?? I think you're thinking of Carbon... Best, -Slashy

HardKerbin, There's a cheat in the Alt+F12 menu that enables you to show drag values when you right- click on a part. You go to Physics/ Aero and enable "Display aero data in action menus". Best, -Slashy