Scarecrow71

You are more than welcome! That is what we are all here for!

@Ariggeldiggel I downloaded the craft file, and I was able to use it. I ran a few tests on the craft, launching it and trying both manually and using MechJeb to get this thing into orbit. And even MechJeb couldn't do it. The simplest explanation here is that your lifting stage just doesn't have enough power to get this thing to orbit. The craft starts with a TWR of 1.05 at liftoff, which is barely enough to get off the ground. In fact, it took several seconds to get off the ground, which just burned fuel. Both manual flying and using MJ, I started the gravity turn at 100 m/s, and this is where things really went wonky. For myself, flying manually, I couldn't get this thing above 20km without it flipping. I checked all the parts, and I checked the fuel drain, and all that. It simply would not stop flipping. So I added a fairing to the top of your craft, just above the reaction wheel you've got in the middle of this thing. And then it couldn't fly because it was too heavy. The fairing gave it aerodynamics, which it desperately needs, but it was just too heavy. I let it run for a few seconds, and it eventually got off the ground...but wasted half the fuel in the first stage to do so. After that happened, I removed the fairing and launched this thing with MechJeb's Ascent Guidance. Again, TWR at launch is 1.05, and the gravity turn was started at 100 m/s. Which, coincidentally, was at about 3500m. You should reach 45 degrees somewhere in the neighborhood of 10km, but even MJ didn't hit that until about 19km. And at 20 km, she started to turn over 45 degrees. Which isn't all that bad, but with TWR was still under 2 at this point. At 22.5km the first stage burned out and the boosters on the side ejected. TWR dropped to 0.6, and for the rest of the flight it never got above 0.65. She reached an Ap of 38501m, at which point she started to come back down to Kerbin. Even with MJ flying, it would not get into orbit. My first suggestion is to redesign the lifter stage and add some thrust/power there. The craft simply does not have enough juice to get off the ground and get to orbit. My second suggestion is to ask why you have a large reaction wheel in the middle of the craft? Normally, reaction wheels (from what I've seen) go near the engines to use their thrust to help with turning. I'm not saying where you have it is wrong, I'm just questioning why.

No, I've got both DLC. Not sure why that error is coming up. Well, I hope someone else can take a peek at this craft file!

Downloaded...and I can't open the craft due to a part on the command module (spotlight3) that I don't have. Did you build this with any mod parts? Or are there parts in 1.12 that I don't have in 1.8?

Can you upload the actual craft file, or paste the contents of the craft file here as text? Perhaps one of us can test the craft ourselves to help you out?

Granted. The next professionally looking, full-featured, handy, and comfy office software in this planet history is released the day after you die. I wish Windows ME was the dominant operating system.

I can't tell for certain, but it looks like the fuel line you have on the bottom of the tanks is flowing from the center tank to the outer tank. I also cannot tell if you have this mirrored on the other side of the craft, or what direction it is pointing if you do. But if this is the only fuel line, or if you have one on the other side but it is flowing from the outer tank to the inner tank, then you are shifting the center of mass in an unnatural way, pushing all the fuel - and thus, all the mass - to one side of the craft. I'm also seeing that you have fins on the rocket, but they are halfway up the center spire. Try putting those closer to the bottom of that spire, just above where the engine connects. And on that note, you don't need the Delta wings; the Basic Fin is more than enough. In addition to all of that, I'd like to add to what @king of nowhere said about dV requirements for a craft. For starters, the amount of dV you have on a given craft will be different depending upon several factors, not the least of which is where you are at. You have less dV when you are on the ground on Kerbin or Eve due to gravity, but that same amount of fuel will provide far more dV in a vacuum. You can use several different tools to see the dV you have in a given stage based on where that stage will be active by clicking on the dV button in the lower right corner in the VAB, and then changing the body (it defaults to Kerbin) and where you are (I believe it defaults to Altitude). This way you can actually see how much fuel in m/s you have for a particular part of the journey. As an aside, you could also install MechJeb, KER, or a host of other mods that give you the dV information as well. Secondly, and I cannot state this hard or fast enough: The engine you are using in a given stage has a dramatic impact upon both dV and the amount of thrust you have in a given environment. When launching from Kerbin or the surface of a planet/body with gravity, you want an engine that has a high thrust at ASL. Conversely, when you are in a vacuum or on a body that has very low gravity, you want an engine with high thrust in VAC. And engines that perform well in one area do not necessarily perform well in the other. I don't know what you are using for your transfer from LKO to, say, the Mun, because the image you provided doesn't show that. But, as an example (and this is a very lousy example that I highly doubt you are using), you wouldn't have a pair of Spiders on your transfer stage trying to push a several ton lander from LKO to Mun, right? Same principle for all transfers; you need an engine that squeezes out the most dV possible while being powerful enough to do burns quickly instead of taking forever. As far as dV and engines and landings go...that just takes time. Landing isn't overly difficult, but it can take some time to get down and get it right. It took me months of using MechJeb's landing module and watching what it was doing before I was able to land. Mostly. Somewhat. And I still botch it ALL THE TIME. You know how you say something is easy and brag about it and then you try to do it and you bork it? Minmus for me, almost every time. This is why Quicksave is my friend. But I digress. The important thing here is that it takes time and patience to learn how to do it, and even when you do you will still make mistakes. Don't let it get you down. Think about what you already have learned how to do since you started (rocket design, launch, terminology, orbit, transfer, etc.) and you'll see that you have already come a long way. Keep it up! Keep pushing! And if you need help? Ask!

Fortune favors the bold. Nice job!

Banned for too long of an explanation.

@OJT For Part III, does it have to be a planet? Like, do moons such as Ike count?

And my entry for the Minmus landing. I forgot to take a shot of the rocket on the launchpad before I took off, so I got one while I was in flight. And getting to orbit was, again, easy; I know I can hit orbit with these parts with no issues. Getting to Minmus orbit was also a lot easier than I thought it would be. I'm so used to decouplers that I freak out when I start having to burn and blast the lower stages. But, I got to the tasty green rock...and I landed in the Greater Flats! I felt it was only appropriate to plant a flag with the Jeb's Junkyard logo on it; I mean, that IS this challenge, right? You will also notice that I used a cupola module this time. I almost went with the lander can/adapter combo that seems to be popular here in this challenge (and that I myself used in the first submission), but I wanted to go a different route this time. I almost - ALMOST - used a hitchhiker container. I might do that if I go interplanetary and just bring all the Kerbals with me. Anyhow, I was able to get back down to the surface of Kerbin...once again by having to deploy Jeb's parachute. Again, not enough fuel to slow myself down first. I ended up making 6 aerobrake passes to try and save as much fuel as possible, but I still can't get slower than about 75 m/s on descent. Alas, that third star continues to elude me! Once again, I will need @OJT to verify my Part II landing!

So here is my submission for Part I. I started with a pretty simple rocket design here, whereby we have the 2 stages separated by a Bobcat engine: I was able to get to orbit easily: Wasn't so easy getting Jeb back on the ground, though. I had to go EVA and deploy his chute, and I've never done that before. So it took me a few moments to learn how to slow his descent and all...and he still bounced like a rubber ball on concrete upon hitting the ground. But he survived! I wasn't able to save any of the craft; without parachutes, I was hoping to use the upper Bobcat engine to slow my descent enough to at least save part of the rocket. No dice; I didn't have enough fuel to slow myself enough. I am certain there are ways other than that to land, but I was going for this one. I would like @OJT to please verify this before I claim my Part 1 badge! Once that is done, I will work on obtaining a landing on Minmus!

Today in my current career I sent Vision III to Ike to gather some science. I had a contract to get science from space around Ike, and even though I want to start a mining operation on Minmus shortly, I couldn't resist the funds gained from the contract. Or the science points (1900 of them) from gathering science in space around and from the surface of Ike. Had to do it. But an interesting thing happened on the way home from Ike. I sent up both a mothership and a lander, and I had the mothership in an elliptical orbit around Duna while the lander went to Ike. The lander did its thing and came back, and I docked easily with the mothership. I then generated a maneuver node to get home, and the window was 3 years away. No big deal; I'll just set KAC and time warp ahead. And after about a month (30 days or so), the mothership was ejected from Duna's orbit and went into solar orbit. Now, I know that I was in a rather ugly elliptical orbit (100km Pe, ~2000km Ap), and this I'm sure played into this happening. It was interesting to me because I've not seen that happen in any of my games before. Anyhow, I had to recalculate the transfer to Kerbin, which ended up being another 3 years away. I got home safely - or, rather, Jeb and Bob got home safely - and all is right with the world. It was just odd that I saw this happen. It ended up costing me ~250 m/s of dV to get to Kerbin's SOI (the original dV required from Duna was 575 m/d, while the transfer from solar orbit was ~825), but I had plenty to spare at that point. This does, however, force me to think about orbits a bit more and how to deal with them appropriately. In other news today, I tested crossfeed on engines. In one of the challenges here, you can only use parts manufactured by Jeb's Junkyard...which means no decouplers. This means that my upper stage was draining into the lower stage, even though I had an engine in my upper stage. So I ran a test to change fuelCrossFeed to be FALSE in the CFG file for one of the engines...and that effectively turned off said engine. It wasn't entirely expected behavior, but makes total and perfect sense that you need fuel flowing through the engine for it to do anything. This is just an FYI for anyone interested; merely a public service announcement. Had this been an actual emergency, this message would be followed by instructions on what to do and where to go to protect yourselves. And with that, we now return you to the arts.

@18Watt So I ran a test this morning on the Bobcat engine. I altered the CFG file for the Bobcat engine, changing the following entry: fuelCrossFeed = True I made this entry to be: fuelCrossFeed = False I then launched KSP and built a rocket using the Bobcat engine for both the upper and lower stages. I did this because I only wanted to alter 1 engine as a test. And the results were...I wouldn't say entirely expected, but based on what's been happening here, they were what I was thinking would happen. Disabling crossfeed on the engines pretty much makes them paperweights. That is, without crossfeed, no fuel even gets into the engines, which means they aren't burning or thrusting or doing anything. This means that we have to have crossfeed turned ON for the engines. This, therefore, makes this behavior expected. It's a bummer that fuel flows from the upper tanks into the lower tanks, but it is what it is. I will have to come up with a way to prevent this from happening on future flights. But, at the very least, I'd like to thank you for your help in this!

I was walking my dog today when I came across a couple of chickens having a rather loud argument. They were cursing and swearing at each other at the tops of their lungs. It didn't bother me, though; it was just a bunch of foul language.

Parts have config files, yeah? Could we turn off crossfeed there?

To me, thats a bug. Especially considering the engines are in different stages and nonfuel lines are in play. I am unaware on how to use that part effectively. I can only get one side of it to ever connect.

To those of you who did this challenge: How did you deal with the fuel flow from upper tanks to lower tanks? I'm having an issue right now that a couple of us are testing, it bears out that engines do NOT prevent crossfeed from upper stages to lower stages. With no decouplers, this means that upper tanks will empty into lower ones even when you aren't staged for the upper engine to be used. How did you get around this?

@18Watt Well, I've got some bad news on this front. I rebuilt the rocket, and I checked the flow priority values in the VAB. As you can see in the following image, the upper tank has a flow priority of -10, while all of the lower tanks have a flow priority of 0. So I took this thing for a test drive, knowing that the flow priority is set correctly. Check the following video; fuel flows from the bottom tanks correctly...until they run out, at which point fuel starts flowing from the upper tank into the bobcat. You can see this happen at about the 3:50 mark. I apologize for the graininess of the video; I'm still relatively new at taking video and uploading it to YouTube. Anyhow, you can see that the fuel empties out of the upper tank without staging near the end of the video. Is this a bug that has never been reported?

I built my ship from the top down, so I assume that KSP dealt with flow priority correctly. However, I'll have to test this when I get some time, most likely later today (Mrs. Scarecrow71 made me take the day off today so we can do errands). I will certainly let you know what happens when I rebuild and retest!

Yeah, I tested this with multiple engines (Cheetah, Terrier, Swivel, Reliant) and got the same behavior every single time. Modded or unmodded. Sandbox, Science, Career.

So I tried this again this morning, but this time in an unmodded game. Same results: the upper tank starts draining into the lower tanks, even though I've got an engine between the upper and lower stages. I staged manually when I saw this was happening, and as soon as the lower tanks exploded (one of them), the bobcat engine stopped firing as it was out of fuel. @18Watt, is there any chance you can test this on your end? Sandbox, normal difficulty, no changes to any settings. If you can build the craft I have above and just see what happens on your end, just to rule out that it's something in one of my games?

Even when I stage manually, the upper tank drains into the lower one. I am going to try doing this in my install that has no mods and see what happens.