Unfortunately my potato internet here won't let me stream. But let me suggest DasValdez that streams on both his own channel and the KSPTV channel, especially his Kerbal Space Academy slots, as good for learning. Also, EJ_sa is good at explaining things although that's not the main focus of his KSP streams. Most of the other "big" KSP streamers (by big, I mean regularly hits the 300 or so mark) are pretty good at explaining things.
Also, I see from your rocket that perhaps you have yet to see the glorious wonders of struts, aka space duck tape.
On March 27 2015 22:00 felisconcolori wrote: Also, I see from your rocket that perhaps you have yet to see the glorious wonders of struts, aka space duck tape.
In fairness struts can't solve everything.
Most things, but not everything. I know from experience that some of my rockets wouldn't work regardless of how many struts I put on them (usually when they totally collapse under their own weight on the launch pad...I've got a very bad tendency to constantly "build up" and if something doesn't work just strap more rockets on it).
Although zooming in seems to indicate that there are struts holding the side-rockets in place. If this is the case then the problem is simply top stability. Its hard to set up struts to stabilise something so long and the top of the rocket is just way too long compared to the base launch part. The side rockets need extending up the side, bracing against the upper part and staged with separation boosters to prevent it from crashing in on itself when ejected. Then it should work fine as the top will be properly braced against the accelerating first stage.
One thing i notice that is not related to the whole "falling to pieces" problem is that your rocket engines are all at different stages of burning through their fuel. That is usually not ideal. Ideally you would want some sort of booster stage, that burns out at roughly the same time (That isn't hard if you just attach 4 similar boosters or something like that, usually via the symmetry tools), which you can then discard to use your higher stage propulsion system, from which you ideally didn't waste any fuel onto burning while the first stage is still active.
On March 27 2015 23:24 Simberto wrote: That rocket is such a glorious mess.
:D The learning curve is the best part of the game imo. If you have any specific questions I could actually stream/upload explanations for you or point you to an existing tutorial that I know.
On March 27 2015 22:00 felisconcolori wrote: Unfortunately my potato internet here won't let me stream. But let me suggest DasValdez that streams on both his own channel and the KSPTV channel, especially his Kerbal Space Academy slots, as good for learning. Also, EJ_sa is good at explaining things although that's not the main focus of his KSP streams. Most of the other "big" KSP streamers (by big, I mean regularly hits the 300 or so mark) are pretty good at explaining things.
Also, I see from your rocket that perhaps you have yet to see the glorious wonders of struts, aka space duck tape.
I meant me streaming, since can do it with a ~5 second delay :D watching an expert is good for some stuff but no practical experience doing the flying stuff
On March 27 2015 23:24 Simberto wrote: That rocket is such a glorious mess.
It actually worked completely fine and gets to mun (maybe minmus too) with alright flying. For that pic though, i had just tripled the engine power with no other considerations because the thrust to weight ratio was too low (friend talked me through building it, but he usually uses a huge list of mods to display stats). The stability was fine with a few struts added, was completely solid until dropping all boosters aside from the biggest one (had to drop throttle to around 200-400 thrust from it after detaching other engines, 650 was too much)
One thing i notice that is not related to the whole "falling to pieces" problem is that your rocket engines are all at different stages of burning through their fuel. That is usually not ideal. Ideally you would want some sort of booster stage, that burns out at roughly the same time (That isn't hard if you just attach 4 similar boosters or something like that, usually via the symmetry tools), which you can then discard to use your higher stage propulsion system, from which you ideally didn't waste any fuel onto burning while the first stage is still active.
That rocket has many stages. It has asparagus staging for dropping fuel from 2 of the side boosters into the other 2 boosters (then discarding the empty fuel tanks), then the last 2 side boosters into the main fuel tank + engine. That burn is enough to get to a stable orbit if flown correctly, then that stage is discarded for another stage which can make the burn to mun and then slow down and decrease orbit a lot (or even land), but there's another very light stage with an engine if that runs out of fuel or for easier landing
I saw some people like scott manley using asparagus staging in some videos, but i didn't really know what it was. That friend said to use it over a bunch of solid fuel boosters strapped together for actually getting out of the atmosphere
The idea is to create a rocket with a lot of parallel rocket engines with fuel tanks on top of them. All engines ignite at the same time. The trick, however, is that each rocket engine isn't depleting its own tank, but they are all draining their fuel from the outermost tanks. When these are depleted, the outmost tanks with their engines are decoupled and the next fuel tank takes over which is still completely full. The result is that the rocket always flies with the minimum number of tanks required to transport the fuel it has left while also constantly using all engines it has on board.
This concept can be realized through fuel lines which connect the stages in the order they will be dropped. It uses the fact that engines will always take their fuel from the most distant fuel tank available.
The main use of Asparagus Staging is to lift heavy payloads with higher mass to thrust ratio, mainly in the form of fuel, to orbit for the purpose of missions to the Mün and beyond. It can also be used effectively for the purpose of Space Station launch.
Only four engines though. Would be better with 6-12 i think. If it's not the most effective or easiest way of bringing stuff up to orbit while having half of the stages left for doing useful stuff, then that's why i'm here :D
Falcon Heavy has been designed with a unique propellant crossfeed capability, where some of the center core engines are supplied with fuel and oxidizer from the two side cores, up until the side cores are near empty and ready for the first separation event.[24] This allows engines from all three cores to ignite at launch and operate at full thrust until booster depletion, while still leaving the central core with most of its propellant at booster separation.
If you have any specific questions I could actually stream/upload explanations for you or point you to an existing tutorial that I know.
I kinda wanna get to Mun and back without just copy/pasting some craft, with several kerbals :D there are two stuck there now that didn't have quite so glorious landings, but the last one was very close
One thing i would suggest is instead of having a long thin top thingy, have more of a broader top. Broader and flat is much easier to land when compared to long and thin.
I'd recommend against anything involving docking for the beginning. Docking, especially without some sort of dock alignment mod, is incredibly hard and the whole maneuver will probably cost you roughly as much fuel as simply flying back to Kerbin would anyways.
You can consider bringing another Pod to rescue your Kerbins, but that is heavy and will require a very precise landing unless you want to spend ages wandering Kerbals about. Even one km off the spot will take ages to walk. Possibly consider making this a later mission and build a rover for picking up your Kerbals. Make sure that extra pod is actually empty when launching, Kerbals have this tendency to sneak in when you are not looking.
(Also, just to make sure, you do know that a quicksave feature exists? I would probably have went mad if had to spend one hour for getting something to the Mun for each of my initial landing attempts until i kinda learned how to do it)
I just wanted to repeat a few times. I didn't have major issues with the landing, just a bit of iteration to learn how it worked and some silly mistakes
it was stuff like first one ran out of fuel due to awful launch and way too bad thrust to weight ratio while in the atmosphere, second one i misjudged that the ground level was actually ~4.5km and decellerated too late, third one i was doing that very precise landing but i used too much fuel messing about to get the position perfect and fell ~4km away from the first pod (didn't get final adjustments in) but half-survived the landing
Accurate radar height above ground is one of the reasons I love Kerbal Engineer (I think it's "Redux" now). Judging distance to ground by eye from an exterior view is a pain, and the IVA view gives you a meter to see height above actual ground but makes any other piloting a pain.
Also, despite what Simberto is saying with regards to Kerbals moving, if you use their EVA fuel judiciously, you can actually get around pretty well on the surface of the Mun. It still might take awhile to go a few kilometers, but it beats walking.
Accurate radar height above ground is one of the reasons I love Kerbal Engineer
Yea, i'm just installing that one now. Stats are good. Dropping from 70m/s to 35m/s at 6km because you have the wrong thrust to weight ratio is very very bad :D (tripled thrust and it was going like 15 times faster)
Just thought I would drop this Kerbal story here, it happened a while ago but it was one of my greatest moments in gaming.
As a newish player, I was attempting to leave the surface of the moon and fly back to Kerbin. I blasted off pretty carelessly and I had a huge odd shaped orbit round Kerbin which was like 100000km at it's closest point and pretty much as far away as the mun at it's furthest point.
In short, I would endlessly orbit. I was out of fuel, running out of power and had all this juicy science lost in space for eternity. I knew that if I could just get into Kerbin atmosphere then the drag would slow me enough each pass round to eventually bring me out of orbit. I made a cup of tea and evaluated my seemingly minimal options.
When I got back, I suddenly had a brainwave, I have fuel in my jetpack! I also knew from my limited space knowledge that to alter my periapsis I needed to make the move at my apoapsis and I also needed to make it back to the ship because I needed the parachutes to land safely.
I got out and did some haphazard faceplanting with the jetpack trying to scrub off as much speed as possible, I missed a few times and flew away from the ship but kept on burning into the nose to slow it down. When I was nearly out of fuel I got back in and hit the 'M' key... 47000km.
See that's the problem, it's close enough to my field (astrophysics) that it feels like im actually studying, and far enough that it doesn't help me prepare any exams
On March 28 2015 00:54 Cyro wrote: I kinda wanna get to Mun and back without just copy/pasting some craft, with several kerbals :D there are two stuck there now that didn't have quite so glorious landings, but the last one was very close
I was recording a short video on this, but then I realized it can be summed up in a few sentences, especially since you're already using KerbalEngineer.
All you need to know are 2 things: what do you want to do and how much delta-v do you need for that. You want to send a bunch of Kerbals to the Mun, so add parts to give them a place for the ride. After the payload add enough fuel+engines to reach the delta-v requirements. For a round trip to the Mun from LKO you need 2600m/s (including a margin of error) - 1100m/s from LKO to Mun orbit, 600m/s to de-orbit, 600m/s to achieve orbit from the surface, 300m/s for the transfer from Mun orbit to Kerbin. Add a touch more delta-v if you are unsure about your piloting skills and there you are. No need to copy any design, just match the numbers and fly (but don't forget the landing legs and pack a parachute).
Piloting that is another story, but before I put together a decently narrated Mun video, you will have watched this one a couple of times:
That's true. The biggest things in craft design are dV (it takes roughly 4600m/s dV to get to LKO, although it can be done with less I believe) and TWR - make sure it's over 1 and ideally for launch stage be around 2.2. Kerbal Engineer in the SPH and VAB have a neat feature that lets you also look at TWR under different conditions - for example, on the Mun, or at Laythe, Duna, etc. Very handy when designing lander payloads.
For a round trip to the Mun from LKO you need 2600m/s (including a margin of error) - 1100m/s from LKO to Mun orbit, 600m/s to de-orbit, 600m/s to achieve orbit from the surface, 300m/s for the transfer from Mun orbit to Kerbin. Add a touch more delta-v if you are unsure about your piloting skills and there you are.
Thanks for the numbers. I'm overbuilding some ATM (actually going to try and build myself to roundtrip minmus) but those are way below the numbers i think i can fly safely and with good thrust to weight ratios :D
just built with 6-way asparagus
Launch stage says 8225m/s, not sure how accurate it is with asparagus stuff. Thrust to weight ratio starts at 2.14 then goes up to 2.97 if engines/tanks are dropped - might limit some engines or not throttle to full if that's too high
stage 2 = nuclear engine with huge tank 4692m/s (total 12899) - for transferring orbit to orbit and maybe slowing down before ditching
stage 3 = lander and returner, 2 small fuel tanks that can be detached: 1509m/s before the detach, then 2818m/s more for 4327m/s thrust to weight ratio is huge for on minmus, ~16-27. I was going to add some of those tiny mini engine things on the extra fuel tanks to level it out, but i don't think it's necessary at all
Total delta-v = 17226m/s
Some issues with detachment, pretty annoying to fix. Might have to re-do a lot of the rocket or just not use asparagus. Other stuff seemed good though, i could probably just make it 6>1 fuel (all fuel into main tank, detach all other tanks+engines at the same time) and it would work
On March 28 2015 02:46 Simberto wrote: I'd recommend against anything involving docking for the beginning. Docking, especially without some sort of dock alignment mod, is incredibly hard and the whole maneuver will probably cost you roughly as much fuel as simply flying back to Kerbin would anyways.
Pff. Go big or go home is my view. ;P
My first Mun mission was a full Apollo-style setup with a separate lander slung underneath a command module for launch that had to be manually decoupled and docked with in order to fly there. Was the devil itself to get to work and learn how to do everything but by the gods did I learn a LOT about how to do things in KSP.
I should really get back to playing that. I still have to re-engineer my interplanetary cruisers so I can actually get it off Kerbin safely. Once its up there its going to be amazingly useful for interplanetary transfers but until I figure out a way its just a large, very expensive, firework.
All of this talk made me play again, moved my 4-contract thing to Duna - explore Duna+Ike, Duna satellite, Duna space station. + Show Spoiler +
On March 30 2015 11:19 Cyro wrote: Total delta-v = 17226m/s
That's way too much for Minmus. Obviously having more delta-v won't exactly hurt you, but that should be enough to do a round trip to Moho (hardest to visit). In terms of efficiency though, don't detach a nuclear engine to switch to a less efficient one unless you really need the TWR from something else. With a nuke you can land on most bodies without atmosphere, only for Tylo it can be tough to the achieve the TWR.
On March 30 2015 20:35 -Celestial- wrote: I should really get back to playing that. I still have to re-engineer my interplanetary cruisers so I can actually get it off Kerbin safely. Once its up there its going to be amazingly useful for interplanetary transfers but until I figure out a way its just a large, very expensive, firework.
If you can't launch it without fireworks, try splitting it up into several launches and construct in LKO. That's also more realisitic than launching one giant thing into orbit.
On March 30 2015 20:35 -Celestial- wrote: I should really get back to playing that. I still have to re-engineer my interplanetary cruisers so I can actually get it off Kerbin safely. Once its up there its going to be amazingly useful for interplanetary transfers but until I figure out a way its just a large, very expensive, firework.
If you can't launch it without fireworks, try splitting it up into several launches and construct in LKO. That's also more realisitic than launching one giant thing into orbit.
To be honest my SOLE issue right now is that decoupling the launch vehicle from the ship itself tends to result in the engines exploding because of engine covering collisions. I was using quad engine mounts with nuclear engines to pack some more power onto each housing. But that meant when I hit the button to release the engines the side panels would fly off to free them and smack straight into the other engines.
I tried to do it carefully but there were always problems with it. Very frustrating after pulling off what was a fundamentally tricky launch procedure.