GoSlash27

Pandaman, You didn't *have to* resort to trial and error just because you were running stock. You could've still properly designed your rockets, it would've just been less convenient than using KER (Nuthin' wrong with that). Not saying you should or shouldn't do things any differently than you do, just saying that running stock and having access to all the important information aren't mutually exclusive. You describe it like you can do things now that you couldn't have done then, and that's not accurate. It is possible to do everything that KER allows without using KER (and indeed things that KER can't do), it's just more of a hassle to do it. Best, -Slashy

Rune, That is a seriously smexy spaceplane! Best, -Slashy

RIC, Yeah, it's a crude rule of thumb and not optimal, but it's generally "good enough for government work". Best, -Slashy

I agree with RIC, but that's not central to my point. I'm just saying that while KER makes it easier to know your DV, it doesn't make it *possible*. It is still possible to know your DV and design efficient vehicles without KER. It is possible to fly well without MJ. It is possible to know your transfer windows without using KAC. A fair amount of folks who use these mods assume that folks who play stock don't have access to the information that they provide and are therefore flying blind, but that's not correct. How important it is to know all this stuff is a different subject. I personally can't imagine planning or running missions without it, but I know there are people out there that do and are successful. My hat's off to them. Best, -Slashy

The simple version for ejection angle: Assuming that you're in an eastbound equatorial orbit If you're transferring to an inner planet, burn at sunrise. If you're transferring to an outer planet, burn at sunset. Best, -Slashy

Actually, not so much. I see this assumption expressed fairly often in this forum by folks who use KER, but it's not actually so. Playing stock and knowing your DV aren't mutually exclusive. Just because the info isn't directly displayed on the screen doesn't mean it isn't available. All the mission planning, DV budgeting during build, optimization, etc. that KER users take advantage of is still available to us stock players. There's no more "guesswork" involved in playing stock than there is in using KER. Now... there are people who choose to play that way and more power to 'em, I'm just saying that you don't *have to* just because you're playing stock. Best, -Slashy

I decided to see how heavy I could go. I think I still have a little room, but here's where I'm at: A little rebalancing needed. I'm hoping to squeeze just a little more out of it so I can put in a docking port. Weighs 19.6 tonnes at launch. A side by side comparo of the single turbojet vs. RAPIER. Not only is the RAPIER smaller and cheaper for the same performance, but it has better payload fraction besides. Best, -Slashy

Shyrka, They're far from "useless". They're ideal for placing kerbals/fuel/oxidizer/monoprop into stations or vehicles under construction in LKO. It's just that turbojet SSTO spaceplanes are going to end up more expensive, larger, and less efficient than RAPIER ssto spaceplanes. Best, -Slashy

Warzous, Wet wings are your friend A couple notes: More intakes than necessary is just dead weight and drag. The flight profile is at least as important as the spaceplane design Maximum efficiency isn't achieved when you can't add any more, it's achieved when you can't take any more away. Best, -Slashy

Shyrka, SSTO spaceplanes really aren't cost effective unless you're just going to LKO and back. If you're going farther than that, it pays to use a vehicle designed for the purpose. I have seen one turbojet hybrid so far that looks to have (potentially) decent payload fraction. ^design ctsy. Juzeris Unfortunately, it's a bit cheaty, so I'm not sure how much it's performance would suffer without resorting to the cargo bay to mask drag. Best, -Slashy - - - Updated - - - capi, Would that 25-30 tonnes require 2 turbojets or just one? Also, what kind of payload fractions are you seeing? Thanks, -Slashy

Mikki, What matters in spaceplanes is payload fraction, which directly impacts their operating cost. If you wish to directly compare each engine type, you need to build aircraft optimized for their engines and compare their payload fraction. RAPIER designs are getting between 20% and 30% payload fractions. I don't know what the current limits are for turbojet hybrids, but I wouldn't expect them to come close to that. Best, -Slashy

If you want full- on realism, you've got to get flight sim X and Superbug/ tac pack. They have a "world at war" expansion out now. Best, -Slashy

I agree with Starhawk (I almost always do). The turbojet+OMS rockets was unbeatable pre- 1.0, but now the RAPIER is superior. Each engine will handle 15 tonnes of spaceplane comfortably and I've pushed some of mine beyond 18 tonnes. For spaceplanes, this will translates to roughly 3 1/2 tonnes payload per engine. Best, -Slashy

Teilnehmer, This seems about right to me, but transsonic drag is liable to mess the whole thing up. Rather than multiplying the thrust to compensate for the gravity difference, why not run it at .64 atm (about 3km)? Your takeoff speed on Duna would then match whatever speed you cruise at. I *think*... The thrust vs drag would balance out at 16km. HTHs, -Slashy

Meithan, I really like the settable atmosphere option. Useful for lower stages. As for the relative acceleration question, I'm like you; I think in terms of Gs at a location when designing a stage. I can definitely see where m/sec^2 would come in handy for timing burns, tho'. Excellent work! -Slashy

Most recent "D'oh moment": Early career rescue-the-kerbal contract mission with ox-stat panels. I had done a correction burn to intercept and time accelerated without realigning my ship. When I came out of warp... rescue ship was flatlined with the panels pointed away from the sun. I had to wait several days for the ship to randomly drift back into alignment to restore power and of course by that time the intercept was blown. Luckily, I had enough fuel to redo the rendezvous and still make deorbit. Best, -Slashy

A_Name, You should let them know you don't understand the charts. They'll be happy to help explain it. It might also give them ideas on how to make the charts more user friendly. Best, -Slashy

It could also be that the comets aren't concentrated around Kerbin, but rather that's the only place that allows us to spot them (that's where all of our deep space radars are). Best, -Slashy

LittleBlueGaming, Remember that these charts define "best" as whatever engine makes the lightest overall stage. If you don't have very much payload or you aren't going very far, then clearly it wouldn't make sense to use a heavy super-efficient engine when a light gas-hog will do. The heavier more efficient engine won't become worth it until the difference in fuel consumed becomes more than the mass of the engine itself. HTHs, -Slashy edit *D'Oh!* Ninja'd...

AbacusWizard, I'd always attributed that concept to the NASA Space Task Group. http://www.hq.nasa.gov/office/pao/History/taskgrp.html Of course, Heinlein often talked about the same concept in his books as well. I wonder who actually thought of it first? Sorry for the sidetrack. Yeah, this is the optimal way to run a railroad IMO. Best, -Slashy

WinkAllKerb, Ah, but that's the rub: People *do* play against each other. Not just in the forum challenges, but anywhere you see people comparing notes. Most of us are just looking for advice or passing on knowledge, but others... They're judging themselves and others by how well they overcome similar obstacles. *These* are the people who accuse each other of "cheating" and concerning themselves with how others choose to play the game. Best, -Slashy

Endersmens, You have to check that to be sure. Remember that the Nerv weighs 2 1/2 tonnes more than the LV-909 and that's not counting the wing sections to keep it from overheating. A proper apples/ apples comparison is difficult to do using KER. All it really says is how much DV you have when you swap engines, and it may be misleading, depending on the situation. The question isn't "which engine will give me the most DV" when designing a stage, it's "which engine, when combined with everything it needs, will give me the necessary DV and t/w with the least mass and cost". This is a question that KER can't answer. We rely on mathematical analysis for that. Meithan is working on an awesome webapp for it. I have ginned up a spreadsheet based on the principles I discuss here. Best, -Slashy

RIC, If I had to guess, it would be because piloting is the active hands-on gameplay portion of KSP. Using MJ to pilot your craft is kinda like using an AI to control your character while playing a FPS. People are bound to call it "cheating", especially if it performs better than an actual human player. Not sayin' *I* consider it cheating, mind you. I was always content to let the computer run the routes in Madden. Best, -Slashy

nadreck, Ain't nuthin' wrong with that! A man after my own heart... The reason I use the drone is because I can set up the Hohmann, drag it around until I get an intercept, and look at the burn timer. It tells me how many days to go until the window opens up. Like most innovations, it came to me after I got tired of doing things the hard way Best, -Slashy

It's probably just a pilot thing. Good pilots rely on their self confidence when things go haywire, so I expect some ego there. A lot of the time, people perceive a "looking down their nose" attitude where it doesn't actually exist. I can't say how much that is, tho'. *shrug* Best, -Slashy