GoSlash27

Nope, nope, and nope. Best, -Slashy

A Martian tweener found it and adopted it as a pet. He cleans it's panels when we're not paying attention Best, -Slashy

I don't know about the "big" picture, but clearly RCS doesn't fit your needs. I build all my stuff to be as light and efficient as I can. Since I can do pretty much everything required in this game with tiny vehicles, vernors are unsuitable for my needs. Your mileage may (and clearly does) vary. Best, -Slashy

Newp. I'm kinda relieved that you didn't get it on the first guess... Best, -Slashy

I've got one. I am the thing that makes the light that you can't see So that the thing that makes the light you *can* see will make the light that you want to see. I am...?

Actually, all the data says we can't. We can theoretically make a tiny decrease in the rate at which things will get worse, but we cannot "stop it". This doesn't mean that we shouldn't do anything at all, but it also doesn't mean that we should rampaging around causing wanton destruction in a vain attempt to do the impossible. A rational approach will include a proper cost/ benefit analysis, not abject panic and hyperbole. Best, -Slashy

Well... I don't think that assigning 1 ram or shock cone intake per engine is "abusing" intakes, and surely any combo with that (or even a whole heckuva lot less) will show the turbojet has an overwhelming performance advantage. Since nobody's ever going to design an SSTO spaceplane that runs out of steam before it even gets to 2 km/sec, I wonder what the point of this line of reasoning is. Perhaps there is a RAPIER vehicle out there that could come close to it's TJ equivalent... but only if it were intentionally designed to be ridiculously inefficient (which nobody does). If you're designing a stock SSTO spaceplane and you want to know which engine is more efficient, the answer is "turbojet". Best, -Slashy *edit* Although I do agree that turbojets are definitely broken.

Oh, I'm with ya... He's actually got a point about the drag being proportional to mass, but what he's missing is that "airhogging" (however defined) actually masks the inadequacies of the RAPIER. If the intake area/ mass is reduced for both, the advantage of the TJ over the RAPIER actually *increases*. Best, -Slashy - - - Updated - - - Your best bet would to be provide an example. Short of requiring an unequal allocation of parts and resources, the math says that this doesn't work out. The exception would be where you declare any use of intakes at all "air hogging", in which case air breathing is disallowed and a properly designed rocket beats the RAPIER. I'm thinking you were comparing an optimized RAPIER to a non- optimized TJ/OMS and misinterpreting the result. I'm keen to try this for kicks, though. Although why anyone would attempt to build an SSTO with severely limited intake area is beyond me... Best, -Slashy

Starhawk, My position is that "airhogging" doesn't factor into it, regardless of how it's defined. The TJ/OMS will outperform the RAPIER in any stock SSTO regardless of whether they're using a thousand ram intakes or a single structural intake. 200 m/sec advantage in flameout velocity, superior t/w, and the ability to run air breathing and rocket simultaneously is impossible for the RAPIER to overcome with it's tiny mass advantage. Best, -Slashy

I'd argue that none of this matters. The only niche where a RAPIER would outperform a turbojet (all else being equal) would be where the mass of rockets attached to a TJ is less than the mass of additional fuel/ oxidizer/ structure required by the RAPIER. Since a TJ/OMS system can get by with a miniscule OMS system (or in some cases none at all), no such regime exists. There's no way you can ever make up for 200 m/sec with 200 kg of fuel and oxidizer. Especially in the 27-32km altitude range where lift to drag is at it's least efficient. Rather than arguing this as a hypothetical, it's a simple matter to prove it conclusively in practice. If you think you can make a RAPIER space plane that's more efficient than a TJ/ OMS, then do it. I say it can't be done. While skewing the rules to favor the RAPIER is a sound approach, it will lead to a false conclusion if the TJ is not allowed to utilize of it's advantages over the RAPIER. TJs transition at a higher velocity than RAPIERs in all cases where the payload and equipment are identical. They also produce more thrust. This is what makes them superior, and taking that away invalidates the results. Best, -Slashy

I certainly hope you can find the time to build one. As for your bullet points... #1 You said 10-15 tonnes. That's what I went with. 13.3 tonnes fully loaded and fueled. #2 To keep it even, you are restricted to 2 XM-G50s, same as I have used. This is comparable to 1 ram intake. The transition speed is whatever it is (a large part of why turbojets are so much more efficient). #3 Sounds fine. I'll just have to put something up in a 120x120 orbit to demonstrate. It should also deorbit and land safely back at KSC. #4 Let's simplify it. The payload is kerbals. As many as you can get up there (each crew cabin is 2 tonnes) . Since we're talkin' efficiency, the benchmark is vehicle mass per kerbal and fuel/ oxidizer expenditure per kerbal. Additional: #5 As I said, it should have RCS, solar panels, and a docking port. I'd encourage anyone who thinks that RAPIERS are competitive with turbojets rocket combos to try their hand at this exercise... Best, -Slashy

Tell ya what: I will build a fully functional SSTO crew shuttle spaceplane(docking port, RCS, solar arrays) within your stated guidelines using a TJ/ OMS system. You do the same with a RAPIER and we'll compare results. Are you game? Best, -Slashy

Depends. What's the environmental impact of artificially increasing the algae population? What are the economic (and thus social) costs involved? Every action has effects. We rarely expect the bad ones... Best, -Slashy

Anyone else besides me notice that this thread is over a year old? Best, -Slashy

^ Update to the above: Here's a best case RAPIER implementation to compare to the TJ/ OMS combo above. Same exact job, but the TJ/ OMS combo works out lighter, more efficient, and cheaper (both to build and operate). In stock, RAPIERS never outperform turbojets/ OMS rockets in an SSTO. I would challenge anyone who disagrees to prove it as I have done here. Best, -Slashy

True. The space requirement isn't a big deal to us, but a major problem for the 3rd world. For them, it's either slash and burn to plant crops or starve. Best, -Slashy

Generally speaking, rejecting somebody else's argument out of hand isn't furthering your own, particularly when you haven't supported your own argument or disproven mine. Do we know whether this global climate change spells the doom of human civilization? No. Can we do anything to stop it? No. Do we know that the "cure" (not really a cure) isn't worse than the disease? No. These answers need to change if you ever want to make a coherent case. Best, -Slashy

Demonstrably false, at least in stock. For any vehicle at any scale, you will wind up with a lower total mass and far less total fuel expenditure by using a turbojet/ rocket combo instead of Rapiers. Rapiers will theoretically give you a lower part count... assuming you don't add batteries to compensate for the Rapier's inability to generate electricity.... but the added weight of fuel required to achieve orbit with RAPIERS means you'll need more structure and thus more wings. By way of demonstration: http://wikisend.com/download/479400/turbojet1.craft The objective here is to place a Mk.1 can in orbit and return it to KSC with minimum overall mass and fuel expenditure. You cannot hope to get anywhere near this level of efficiency using RAPIERs, but you're welcome to try. Best, -Slashy

More like crashing driving off a cliff at 39.9998 mph instead of 40. And how do you know it's "better"? What are the costs in the meantime for imposing a crash effort (assuming you could, which you can't)? How many additional people would die in the name of "slowing global warming"? I'm not a betting man, but if I were I'd be willing to lay down huge money that you've never considered that angle. Unintended consequences and such... For that matter, how do you even know there's a "crash"? Climate has been changing since the dawn of time, and the planet has always corrected itself. The idea that "attempting something you know you can't do at any cost is better than doing nothing" is a logical fallacy.

I'm not sure even that would do the trick. People were clearcutting and burning a lot of trees back then. And even if we could reduce our carbon footprint to zero (stop breathing, etc)... does it reverse the climate change? Last I checked, the answer was no... Maybe slows it a hair. Best, -Slashy

Nobody's arguing for cataclysmic asteroid impacts, just as nobody's arguing for climate change. You stand about as much chance of stopping either of them. In fact, you've got a *better* chance of stopping the asteroid impacts. At least that's theoretically possible.... Best, -Slashy

IRT the OP: Whether we "need to" stop climate change or not is debatable, but moot; we can't. I'm not getting into the rest of it. Too political. Best, -Slashy

I have found one job that is useful for satellites in stock: Finding interplanetary launch windows. I put a tiny sat in orbit around Kerbol just outside Kerbin's SoI. Then I can use it's maneuver nodes to tell me when my launch window opens up to whatever planet. Best, -Slashy

All the craft I build are too small to justify Vernors. I can easily see how they would be preferred for larger craft, though. Best, -Slashy

I can't say that I have. By the time I launch a mission I've done enough planning, calculation, and testing to assure myself that it'll work. Best, -Slashy