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Just 1 cm before throwing this game in a bin


Ariggeldiggel
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Hello dear community,

 

sorry for being rude in the title, but I'm extremely annoyed, angry - Yes: Absolutely liquided off. I bought KSP just a week about and I'm around 90 hours playtime now. At first it was very frustrating, that the tutorials are partially buggy and so it's almost impossible to get a clue of the complexity of this game. But I worked myself through, managed to build a rocket, get into orbit, land on the moon of kerbit and even managed to build two space stations with around 30 flights and coupling processes in order to build it together in space.

It is a total pain in the a** for me, even though I'm enjoying the game, because nobody explains you just anything of it. A friend of mine started KSP the same time I did and he broke his keyboard and mouse because he didn't manage to understand even one single thing. He wasn't even able to get into orbit after 40 hours. However, I'm trying to install a moon base with ore mining, so I can refuel my ships at the space station around the moon before landing on the moon, because I'm not able to get even close to have enough fuel with any rocket bigger than a cockroach to land on that piece of rock. It's even extremely hard for me to have even enough fuel to get into Kerbits orbit. And now? In 3 days, over 30 hours, I've built 7 different version of my mining payload, because none of them were even close to get into space. On top of that I build 19 different version of carrier rockets, to get it up. They were too heavy, didn't get into orbit, didn't get to mun, weren't landable or in most cases: Didn't have enough fuel. This HORRIBLE!!!! fuel thing is driving me way more than insane. I always don't have enough fuel. 90% of the time in that game I only run out of fuel. Now I have enough fuel, enough Delta V, enough TWR to hopefully manage to get this thing to mun. And what now? Now that thing flips and flips and flips and flips. Aerodynamics are fine and it flips. Do you maybe have any ideas how to fix it?

I'm so close to finally raging and throwing my computer out of the window - Just to throw napalm afterwards.

 

Greetings

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2 hours ago, king of nowhere said:

Try maybe with basic designs like this

I already landed on the mun several times. It's not about landing on that thing, it's about installing a mineral-, fuel- and ore station. If it was landing about the moon I would not build that big.

3 minutes ago, HebaruSan said:

All the fins should be at the bottom. Otherwise they'll either not help or make the flipping worse.

So like this?

https://imgur.com/a/ubQmQCP

 

If I put them further down the center of lift will be at the rockets feet

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9 minutes ago, Ariggeldiggel said:

No, that's the middle. Those won't do anything.

9 minutes ago, Ariggeldiggel said:

If I put them further down the center of lift will be at the rockets feet

That's what you want, as far down from the center of mass as you can manage. That way they impart a counter-force when the rocket drifts off of prograde.

Edited by HebaruSan
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6 minutes ago, Ariggeldiggel said:

Doesn't work. It flips like there's no tomorrow.  https://imgur.com/a/OdMjMqq

vR31lOi.jpeg

The center of mass is still pretty far back from all that draggy stuff up front (I'm not sure about the current state, but it at least used to be the case that the center of lift marker doesn't reflect drag, when it really needs to for a case like this). You can either move the center of mass upwards (those outer side tanks could be dragged upward pretty easily with the translate tool) or add more fins at the bottom (or both, depending on how bad the problem is).

It sounds like you may have been relying on some rules of thumb for planes; there are important differences between planes and rockets. A plane relies on lift to counteract gravity, so it wants to keep its center of lift near the center of mass, whereas a rocket mainly just flies straight into the airstream in a ballistic arc and relies on its engines' thrust to keep it moving. The farther a rocket's center of lift is from its center of mass, the more stably it will fly.

Edited by HebaruSan
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1 minute ago, HebaruSan said:

It sounds like you may have been relying on some rules of thumb for planes; 

Well.. No.. The rule I followed was "Oh. Yes. That looks about right. Let's try it!" The last 70 hours this worked perfectly and all was fun. But this now is.. Well. Yeah.. Not at all.

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13 minutes ago, Ariggeldiggel said:

Well.. No.. The rule I followed was "Oh. Yes. That looks about right. Let's try it!" The last 70 hours this worked perfectly and all was fun. But this now is.. Well. Yeah.. Not at all.

The stuff you're doing now is harder than the stuff you did earlier, and once you master this newer stuff, you'll be able to go back and do the older stuff even better.

Another fun, slightly exploity trick is to manipulate the fuel drain priorities on those tanks so the bottom ones drain first and the top ones drain last. This has the effect of moving your center of mass upwards during flight, sometimes enough to help a flip-prone design.

Edited by HebaruSan
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@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.

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2 hours ago, Ariggeldiggel said:

Well. This big stuff worked to get up there... It's not even the biggest object flowing around in my orbits. I already did everything with smaller rockets. I landed on the moon with a small rocket about 20 to 30 hours after buying the game. Now I just wanted to start building an infrastructure - Research stations and fuel stations around kerbit and mun as well as satellites. Kerbit already got a research and fuel station, kerbit and mun have each 2 satellites and the mun got a station that combines research and fuel. Only thing is missing is a mining spot on the mun aswell as a real mun base.

That's my kerbit research station for example:

https://imgur.com/a/HSeNWBY

That was a good sequence of coupling trainings. With some fails and so on it took me around 15 couple processes to build it together in space. After that I saw somebody on youtube who shot a whole station up in space and thought "Wanna do that to". After that the mun station was created that you can see above.

ok.

then you're not somebody who just started and is stumbling on the early roadblocks. you already figured out a lot of stuff, and you're trying to do very difficult stuff. What can I say, it's part of this game. It took me weeks to get my most ambitious projects to work.

29 minutes ago, Ariggeldiggel said:

Okay, now I'm really sad. I bit the bullet and built it way, way smaller. The end? It does the same. Flips to west, when I turn to east. No matter what I do......

https://imgur.com/a/jKzDFHe

I removed the spotlights, so it should work for you now: https://1drv.ms/u/s!AhlFszFINTbFcFvzXUTIexezecE?e=EBb7C7

I can't open the vehicle in the VAB, says it's incompatible with this version (1.12, unmodded).

But I can give some general pieces of advice:

1) as @Geonovast said, you can pull your payload instead of pushing it, and that's stable. I launched some unbelievable crap this way myself too.

2) when ships have big aerodinamic problems, you can avoid gravity turning, and just go straight up until the atmosphere is thin enough. If you flip anyway, slow down too; if you climb vertical and slowly, you'll never flip. Of course, this will suck a lot more deltaV, but I see you're not afraid of making a bigger rocket....

3) that spherical crew pod, that's extremely draggy. No idea why, it doesn't look bad, but it's worse than a flat tank. swap it for a normal Mk1, and it's likely to improve a lot

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8 minutes ago, Scarecrow71 said:

@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.

Well, you surely can say if I've done something terribly wrong, I've no doubt I did mess up a ton of stuff. The position of the reaction weels.. To be honest? It's random. I just put them here and there to make sure it's distributed very evenly. Why? Because I thought it was best if the power of turning is distributed quite well. If that's wrong, it's wrong and I've to change it.
I chose a TWR between 1.00 and 1.10, because I thought "You need 1 to get off the ground, the rest is wasted power and is invested better in more Delta V by more fuel" Why? Because I always have a fuel problem. Usually I start the rocket and never turn it until I reach the apoapsis. So I give full throttle, wait for the apoapsis to get to 100km and set a maneuver for creating an orbit. After that I start throttle with focus on the maneuver node at T - throttletime/2. Three days ago I started to turn the rocket while starting to the 45°. How I do it? Completely intuitive and I guess completely wrong.

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4 minutes ago, Ariggeldiggel said:

Well, you surely can say if I've done something terribly wrong, I've no doubt I did mess up a ton of stuff. The position of the reaction weels.. To be honest? It's random. I just put them here and there to make sure it's distributed very evenly. Why? Because I thought it was best if the power of turning is distributed quite well. If that's wrong, it's wrong and I've to change it.
I chose a TWR between 1.00 and 1.10, because I thought "You need 1 to get off the ground, the rest is wasted power and is invested better in more Delta V by more fuel" Why? Because I always have a fuel problem. Usually I start the rocket and never turn it until I reach the apoapsis. So I give full throttle, wait for the apoapsis to get to 100km and set a maneuver for creating an orbit. After that I start throttle with focus on the maneuver node at T - throttletime/2. Three days ago I started to turn the rocket while starting to the 45°. How I do it? Completely intuitive and I guess completely wrong.

Ok, then we discovered the big problem. You are spending a lot more fuel than you should on your launches.

Ideally, you should have TWR between 1.5 and 2. The reason is, while you are firing your rockets and barely lifting, you are wasting a huge amount of fuel. You'll see your first stage already is half empty and you barely gained 50 m7s of speed. The more thrust at start, the better - the only practical problem is when the engine mass starts getting too much, or when you accelerate too much too early and it causes aerodinamic problems. In fact, you often put fast-burning boosters just to increase thrust in the first minute of flight. Even if you're launching slowly to reduce aerodinamic problems, you want to go fast at first. I am launching a big flat surface right now, and the best flight profile is to accelerate at full thrust (TWR 2) until the craft reaches 180 m/s, and only then throttle down and stabilize speed.

And - provided you're not having huge aerodinamic issues - you should turn early. You reach orbit by gaining lateral speed; all that vertical burn? that's wasted fuel. You can't help it, because you have to get out of the atmosphere, but the less you burn vertically, the better. On airless bodies, an efficient launch entails pointing just enough above the horizon that you don't smash into the nearest hills.

So, as others have said, at 10 km altitude you should be inclined by around 45 degrees. This also needs some thrust to work, or your rocket will just lay down.

On the downside, I just told you to launch at low speed and go straight up to reduce aerodinamic problems. If you were already doing that, then those problems are even worse than we thought. I'd be real curious to try your rocket, no idea why it doesn't work on my pc

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1 hour ago, Ariggeldiggel said:

I removed the spotlights, so it should work for you now: https://1drv.ms/u/s!AhlFszFINTbFcFvzXUTIexezecE?e=EBb7C7

This one got to orbit OK for me out of the box, but it was a very delicate, challenging launch. The thrust at launch is indeed quite low, but that's more of a minor inconvenience than a launch-wrecking problem. The real difficulty was the very low thrust after the side tanks are emptied and detached (the initial TWR of that stage is something like 0.3). To deal with that, I performed a very gradual gravity turn (tilt eastward just enough to notice the prograde marker moving slightly away from vertical, then straight up till at least 200 m/s or so, then lock prograde), which incidentally helps with flipping, then when the prograde marker started to drop too fast toward the horizon, I kept the nose pointing thirty-ish degrees above it until well outside the atmosphere (locking prograde again once the time-to-apoapsis stabilized at about 8s and started ticking back up). This managed to pull the prograde vector up just enough to give me time to get up to orbital speed.

Spoiler

lMbiRka.png

That probably isn't too easy to follow if you haven't done something like that before, so I would recommend making the craft easier to launch instead of trying to replicate what I did with this one. My ideal launch profile is to tilt a degree or two eastward off the pad, lock prograde early, reach 45 degrees around 10km, cut thrust when the desired apoapsis is reached, then thrust again to circularize. Try to keep all your stages' initial TWR at or above 1.0 and you'll have an easier time.

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I haven't had as much fun in ages reading this thread. When I checked the pictures my fist incline was are those side boosters using... Mammoths?

Don't get me wrong, I'm not laughing at you. Creating monstrous rockets is part of the fun and, you, sir, do have a talent for that.

However, a lot can be learned from a "smaller is better" approach, and I emphasized the "learn" word there because I don't mean it as "your aim should be to build tiny rockets" (dream big! build big!) but more that your KSP engineering skills will improve quicker when focusing on smaller rockets first. It's perfectly feasible to go Mun and Minmus using only 1.25m tanks and engines, and just by trying to cut down the weight and part count of a rocket (and launching it again and again and again) you'll develop a better feeling for what good TWR's are, what aerodynamically works and what doesn't, where to place struts, and so on. And once you've mastered that, gradually work your way up to landing bigger and bigger craft on the moon.

And then post a picture of your successful mining/refining operation.

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KSP is not like most games and making several failed attempts before you work out a ship design is just normal even for the old pros. If you get discouraged, remember that it's not easy even for the professionals. 

 

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12 hours ago, Kerbart said:

I haven't had as much fun in ages reading this thread. When I checked the pictures my fist incline was are those side boosters using... Mammoths?

Don't get me wrong, I'm not laughing at you. Creating monstrous rockets is part of the fun and, you, sir, do have a talent for that.

However, a lot can be learned from a "smaller is better" approach, and I emphasized the "learn" word there because I don't mean it as "your aim should be to build tiny rockets" (dream big! build big!) but more that your KSP engineering skills will improve quicker when focusing on smaller rockets first. It's perfectly feasible to go Mun and Minmus using only 1.25m tanks and engines, and just by trying to cut down the weight and part count of a rocket (and launching it again and again and again) you'll develop a better feeling for what good TWR's are, what aerodynamically works and what doesn't, where to place struts, and so on. And once you've mastered that, gradually work your way up to landing bigger and bigger craft on the moon.

And then post a picture of your successful mining/refining operation.

Yeah this was fun to read:D

He did exactly what I (and many other I guess) did when I started playing. I used to assume: better means bigger.  "Moar boosters!", you know? Let's put the huuuugest engines on the huuugest fueltanks and strap some moar huuuge tanks to that. Poweeeeer!
I used to have the exact same problems, the flipping, the raging...

But when I look at my go to launcher(s) now, they aren't nearly as big as when I started. They are efficient and purposeful though.
And, when I really want to have some big monstrosity, I do multiple launches and assemble in orbit. That way you can discover a whole new set of frustrations: those wonderful fits of rage that go with learning how to rendez vous and dock. Good times!

 

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Hey guys, 

many of you are talking about how big my rockets are - But how on earth should I get a mining machine up to mun without building big enough?^^ I tried to use smaller tanks and smaller engines, but there I get to 1500m/s DeltaV and around ~0.2 TWR :o. That will never ever get to orbit :o.

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1 hour ago, Ariggeldiggel said:

Hey guys, 

many of you are talking about how big my rockets are - But how on earth should I get a mining machine up to mun without building big enough?^^ I tried to use smaller tanks and smaller engines, but there I get to 1500m/s DeltaV and around ~0.2 TWR :o. That will never ever get to orbit :o.

One of the options is split the ship in pieces and launch it in multiple launches building it in orbit. 

One question. Are you playing in career or science mode? And if so, do you have the entire tech tree unlocked?

I know that I generally try to keep my launches ideally at 1.3 TWR at launch. If it's higher than that, I intentionally lower the thrust of the engines. I find a 1.3 TWR to be a bit of a sweet spot for control at launch. 

Rylant

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1 hour ago, Ariggeldiggel said:

Hey guys, 

many of you are talking about how big my rockets are - But how on earth should I get a mining machine up to mun without building big enough?^^ I tried to use smaller tanks and smaller engines, but there I get to 1500m/s DeltaV and around ~0.2 TWR :o. That will never ever get to orbit :o.

Well, I’m not saying you can’t build big rockets, and surely large payloads require large rockets.  But… my recommendation, based on your disclosure that you just started the game some weeks ago, is don’t go there yet. Build up some experience in constructing rockets. Learn to build lean, and get skilled at putting things into orbit,maneuvering them, and landing them.

As your DV requirements to safely land on Mun shrink, so do your launch requirements (not to speak of what you need to get into orbit in the first place) . My advice to focus on getting the smallest craft possible to the surface of Mun and back will allow you to fail fast (a 30-part rocket takes less time to build than a 300 part), and learn quickly. Many missions will teach how much DV you really need. Finally, that refinery doesn’t have to be2.5m parts for starters either. The smaller parts are not as efficient, but neither is what you’re launching right now.

Build a lot. Learn a lot. You’ll end up with 1/2 (or less) of the rocket to put your refinery on the Mun.

 

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3 hours ago, Ariggeldiggel said:

Hey guys, 

many of you are talking about how big my rockets are - But how on earth should I get a mining machine up to mun without building big enough?^^ I tried to use smaller tanks and smaller engines, but there I get to 1500m/s DeltaV and around ~0.2 TWR :o. That will never ever get to orbit :o.

https://kerbalx.com/king_of_nowhere/Recycling-Point-Express-RPE

here is a miner/tanker perfectly capable of mining fuel on mun and bringing it around, while being relatively small (the orbiter is 80 tons fully loaded). it also has a very stable launch system, included in the description, no need to steer.

And it's not like it's any more aerodinamic than your stuff.

17 hours ago, Kerbart said:

I haven't had as much fun in ages reading this thread. When I checked the pictures my fist incline was are those side boosters using... Mammoths?

Don't get me wrong, I'm not laughing at you. Creating monstrous rockets is part of the fun and, you, sir, do have a talent for that.

However, a lot can be learned from a "smaller is better" approach, and I emphasized the "learn" word there because I don't mean it as "your aim should be to build tiny rockets" (dream big! build big!)

 

Dream big? Dream big? Somebody is mentioning my old mothership?:D

it needed 28 mammoths for the mothership alone, plus many others for all the other docked ships.

its successor, A'Tuin, needed something around 50 mammoths instead.

Edited by king of nowhere
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4 hours ago, Ariggeldiggel said:

many of you are talking about how big my rockets are

Don't worry too much about that. I tried deleting your launcher and building a new one in my own style for the same payload, and mine ended up at about the same scale (about 100t heavier, in fact, but with a bit more vacuum Δv, now orbiting the Mun in one of my saves near your version):

Spoiler

t7lJa9J.png

If you wanted to downscale, I think you'd need to send up a smaller mining rig.

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1 hour ago, Rylant said:

I also would like to say that Mike Aben videos don't get the love that they deserve. I find that he has a way of explaining things really well. He does have a video which explains rocket tipping during launch. I thought it was great. 

Rylant

And the link to said video:

 

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On the larger bit about learning KSP: I was in  your shoes once .  I found this tutorial which changed everything.  It is 7 years old now, but except for the DLCs, it will all be the same.  I would not be here now were it not for this criminally underrated series.  The reason I liked it: it was geared towards beginners.  There is a ton of KSP content out there, but actually not a whole lot for those who are brand new.

The time spent in the tutorials will be a lot of time saved banging your head against the wall or throwing your keyboard.  :)

 

 

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