|
On March 30 2015 23:48 -Celestial- wrote:Show nested quote +On March 30 2015 23:07 nimbim wrote: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.
Use timewarp immediately after hitting the stage button, makes the panels disappear.
|
On March 30 2015 23:54 nimbim wrote:Show nested quote +On March 30 2015 23:48 -Celestial- wrote:On March 30 2015 23:07 nimbim wrote: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. Use timewarp immediately after hitting the stage button, makes the panels disappear.
Honestly did not know that. I'll try it. Thanks for the tip.
|
United Kingdom20285 Posts
I'm just having weird detachment issues.. releasing the second set of 2 engines caused the rocket to split in half further up with no evident collision. Maybe i was just throttled up too high?
|
On March 31 2015 05:44 Cyro wrote:
I'm just having weird detachment issues.. releasing the second set of 2 engines caused the rocket to split in half further up with no evident collision. Maybe i was just throttled up too high?
Unless the stage you're detaching is still firing, throttle shouldn't matter. I guess the stock question is if you're using the 64bit client? That's the most common source of errors.
|
Magic Woods9326 Posts
|
You're thinking it's the decoupler issue that Squad hasn't been able to fully fix yet?
|
United Kingdom20285 Posts
On April 03 2015 04:40 Ljas wrote:Show nested quote +On March 31 2015 05:44 Cyro wrote:
I'm just having weird detachment issues.. releasing the second set of 2 engines caused the rocket to split in half further up with no evident collision. Maybe i was just throttled up too high? Unless the stage you're detaching is still firing, throttle shouldn't matter. I guess the stock question is if you're using the 64bit client? That's the most common source of errors.
I'm using 32 bit client. Was detaching engines that were off - but i tried it and it indeed broke several times at 100% and 25-50% throttle, but worked fine when i went into a slight roll and slowed throttle to 0%. I just took the same craft and launched it like 8 times and eventually it didn't randomly disconnect all of the fuel tanks from eachother (not even decouples, but like the glue of the ship between parts suddenly disappearing with no explosion as soon as i decoupled the second set of 3*2 engines)
I got to minmus and back with a kerbal :D
..alive :D
i would rate that harder than mun though. It's much further out and then you have to correct for inclination and time it to dodge mun on your way out, and then the gravity is so weak it was quite confusing for me to actually get into a proper orbit. I didn't have an orbit, just a line that said minmus escape in X time (when i was in the SOI) and i ended up using twice as much fuel as i actually needed for the transfer stage (around 2000m/s of delta v) but i had 4x as much as i needed, so all good
+ Show Spoiler +![[image loading]](http://i.imgur.com/X07uMSB.jpg) ^moments before i realized that i forgot to deploy landing gear ![[image loading]](http://i.imgur.com/QcDkBnu.jpg) ^a minute later, landed :D ![[image loading]](http://i.imgur.com/SGHo722.jpg) ladders down! ![[image loading]](http://i.imgur.com/XJXjlAn.jpg) The weight of my kerbal leaving the pod caused some slight problems for craft stability. Another reason why Minmus is hard! ![[image loading]](http://i.imgur.com/QkU31X2.png) how the fuck did i manage to mess up the angle so badly by accident ![[image loading]](http://i.imgur.com/XBpMtyM.jpg) wheeee 3km/s @30km :D :D
|
I'm really not convinced the decoupler issue is a bug. I think people who are having problems with separated stages torquing in are attaching the booster too high on the decoupler.
If the decoupler is below the center of mass of the booster, it will create a torque that rotates the bottom of the booster away and the top of the booster towards the ship. If the booster is long enough, that could easily overcome the horizontal velocity of the booster.
To fix this, place the booster as low on the decoupler as possible.
It's a design flaw in your rockets, not a bug in the game.
|
On April 03 2015 12:55 Millitron wrote:
I'm really not convinced the decoupler issue is a bug. I think people who are having problems with separated stages torquing in are attaching the booster too high on the decoupler.
If the decoupler is below the center of mass of the booster, it will create a torque that rotates the bottom of the booster away and the top of the booster towards the ship. If the booster is long enough, that could easily overcome the horizontal velocity of the booster.
To fix this, place the booster as low on the decoupler as possible.
It's a design flaw in your rockets, not a bug in the game.
If it's a torquing issue, though, wouldn't placing the booster as low as possible then lead to the opposite problem with the decoupler kicking the upper part of the booster stage out and causing the bottom of the booster to rotate around and colliding with engines?
Actually, I've seen that happen, so decoupler placement might be really finicky. I generally just add sepratrons to push the decoupling booster away and down from the primary stage.
|
Magic Woods9326 Posts
I'm not sure if his problem is the decoupler issue. The decoupler definitely changed from 0.23.5 to 0.24.2, that fix changes it back to 0.23.5.
|
On April 03 2015 13:10 felisconcolori wrote:Show nested quote +On April 03 2015 12:55 Millitron wrote:
I'm really not convinced the decoupler issue is a bug. I think people who are having problems with separated stages torquing in are attaching the booster too high on the decoupler.
If the decoupler is below the center of mass of the booster, it will create a torque that rotates the bottom of the booster away and the top of the booster towards the ship. If the booster is long enough, that could easily overcome the horizontal velocity of the booster.
To fix this, place the booster as low on the decoupler as possible.
It's a design flaw in your rockets, not a bug in the game. If it's a torquing issue, though, wouldn't placing the booster as low as possible then lead to the opposite problem with the decoupler kicking the upper part of the booster stage out and causing the bottom of the booster to rotate around and colliding with engines? Actually, I've seen that happen, so decoupler placement might be really finicky. I generally just add sepratrons to push the decoupling booster away and down from the primary stage.
Placing the booster low will indeed torque the bottom of the rocket in, but that's generally not as bad as the top torquing in.
|
On April 03 2015 12:00 Cyro wrote:I got to minmus and back with a kerbal :D ..alive :D i would rate that harder than mun though. It's much further out and then you have to correct for inclination and time it to dodge mun on your way out, and then the gravity is so weak it was quite confusing for me to actually get into a proper orbit. I didn't have an orbit, just a line that said minmus escape in X time (when i was in the SOI) and i ended up using twice as much fuel as i actually needed for the transfer stage (around 2000m/s of delta v) but i had 4x as much as i needed, so all good + Show Spoiler +^moments before i realized that i forgot to deploy landing gear ^a minute later, landed :D ladders down! The weight of my kerbal leaving the pod caused some slight problems for craft stability. Another reason why Minmus is hard! how the fuck did i manage to mess up the angle so badly by accident wheeee 3km/s @30km :D :D
Gratz :D The difficult part of landing on the Mun is not getting into the SOI. Go botch some Mun landings for science :D
|
United Kingdom20285 Posts
![[image loading]](http://i.imgur.com/eJhLlf3.jpg)
SOMEBODY GET ME SOME MORE DUCT TAPE
![[image loading]](http://i.imgur.com/Pm6SLYI.jpg)
edit: Mission success. I recorded from the first time i pressed button to go to launchpad (missed struts on some part, instant fireworks) and it actually worked right out from the second time going to launchpad. I tested the lander+transfer stage quickly before building that launch monstrosity, but still surprising :D
an hour and a half later, got to the mun with 1 kerbal and came back with four, in one launch. One of them was 40km away from the others, and all of my kerbals were in the middle of the dark side of the mun (i landed them on light side and thought it was tidally locked? :0) so there was some added challenge and derp reloading there. Also i had another bug where my SAS just didn't respond while i was trying to pick up the last kerbal and i had to manually maneuver and land without it >____>
uploading whole thing to youtube if i can anyways in case anyone wants to see the launch and/or skip through it :D
t;t youtube does not accept videos longer than ~10-15 min without talking to them on phone to verify account
|
Magic Woods9326 Posts
oh god the stock rocket designs o_o
|
Tidally locked means that the same side of the Mun faces Kerbin at any given time, and that is correct. It does not mean that the same side of the Mun is facing the SUN at all times, which is what makes it light up. You can easily watch this phenomenon in real life, too. It is the reason why there is such a thing as half-moon, full-moon, new moon, but the craters are always at the same spots.
If you wait for half a month, the dark side and the light side will have changed places.
As to your SAS not responding, were you out of electricity?
And that thing is MASSIVE overkill to get to the Mun. You should be able to easily get to Duna and back with something that size. Don't get me wrong, it is definitively cool. But with a few tweeks you should be able to do much larger missions with it.
|
United Kingdom20285 Posts
Can you get more powerful engines w/ any popular mods? Asparagus feels weak on crafts that heavy because you can't do the usual trick of having the main engine 2-3x as powerful as the booster engines when the booster engines are the highest thrust ones available. Doing that allows you to maintain TWR in the ~1.5-2.2 range, while this craft fell gradually to barely over 1.0 TWR as it dropped engines
i'm sure you could design a craft for the same mission that was smaller and worked fine with smaller than max size engines for asparagus stages, but where's the fun in that?
Tidally locked means that the same side of the Mun faces Kerbin at any given time, and that is correct. It does not mean that the same side of the Mun is facing the SUN at all times, which is what makes it light up.
Ah yea. Shit~
As to your SAS not responding, were you out of electricity?
nop i don't think so, i leave the meter open and i could still use the reaction wheels fine. The SAS just stopped adjusting my craft towards the heading i told it to (retrogade) even when clicking on/off of it
And that thing is MASSIVE overkill to get to the Mun.
And back with three extra kerbals, plus 2-3x redundancy for fuel for fun and shit piloting? :D maybe, but more/bigger engines is always cool. It was like my fifth attempt at a return trip and needing a bunch of pods (or in this case 1 small pod and 1 huge pod) to fit them in. It was pretty awesome aside from some control issues in one stage and lack of TWR for the second half of main stage (if there was an engine with 6-10k thrust, that would be fixed with one part swap)
|
I think you overestimate how important TWR is. TWR is only important for landing and starting maneuvers. Anything out in space you can easily do with lower TWRs (albeit it being slightly annoying if it is too low due to maneuvers taking longer acceleration times which you can not accelerate time to get through. Which allows you to use effective engines like the nuclear ones.
As soon as you are even on a suborbital course, TWR is usually no longer a big issue.
|
United Kingdom20285 Posts
On April 06 2015 21:17 Simberto wrote:
I think you overestimate how important TWR is. TWR is only important for landing and starting maneuvers. Anything out in space you can easily do with lower TWRs (albeit it being slightly annoying if it is too low due to maneuvers taking longer acceleration times which you can not accelerate time to get through. Which allows you to use effective engines like the nuclear ones.
As soon as you are even on a suborbital course, TWR is usually no longer a big issue.
It makes a huge difference if you're dipping that far below and you're nowhere near a stable orbit. A 0.73 TWR on the ground might be higher if you're using that engine at 30-35km, especially after you partially empty fuel tanks - but it's still awful and barely usable for the second half of orbital insertion
i'm sure at 1.8 TWR it would fly like a dream~ "start slow, get slower" is just icky design. Functional TWR of ~1.6 - 1.1 (average ~1.2) is just too low to get out of atmosphere efficiently
|
xD well there is nothing efficient about that design. Just look at all the reaction wheels you needed to compensate for its insane mass (don't use nose cones unless you've installed FAR btw). There's nothing wrong about what you're doing ofc, but it's not efficient^^
It's like Simberto said, you only need a certain TWR for the critical burns, i.e. while fighting gravity and atmosphere. Once you're in LKO you definitely don't need a specific TWR anymore and the Mün has very low gravity obviously (1.63 m/s²). It's perfectly normal IRL that rockets have a TWR barely above 1 after decoupling boosters, they pick up speed while the fuel depletes.
On April 06 2015 23:23 Epoxide wrote:
You should look for engines with high ISP when outside of the atmosphere, typically the nuclear engine is the most efficient for transfers between planets/moons.
Also, using just 1 engine while you don't need the extra thrust is always best in terms of efficiency. Don't attach 8 LV-N to get more thrust, that's actually less efficient than another single engine with lower Isp. I can't find the table right now, but iirc anything above 4 LV-N is less efficient than using 1 LV-T30 (Isp=370s).
There are some cases when a smaller engine will be more efficient than a LV-N, but in general just use them for space. http://imgur.com/a/iNqmQ#0
|
Magic Woods9326 Posts
You should look for engines with high ISP when outside of the atmosphere, typically the nuclear engine is the most efficient for transfers between planets/moons.
|
|
|
|
|
|
EPT
