Diagnosing my Satellite?

[Solis]

1 hour ago, Ohm is Futile said:

Failing that, I'm guessing there's something the user may be doing during ascent that somehow breaks this rocket. Without more information, I really couldn't tell.

I have another rocket like this just without the outer boosters and I can get that one into orbit very consistently.

There are some fuel lines connecting to the center booster(maybe thats a small difference) and it seems to fully refill the center booster when I decouple them. (Im not sure if that happens on PC)

Also worthy to note that the service bays are very wonky. I can fit 5 or 6 rechargable batteries in one and a drone core. I thought that may cause problems so I made 2 service bays one for batteries, but I still have one clipping into my main booster. Maybe that can cause some slight physics changes.

And theres always a possibility that my game is bugged or that PS4 is indeed a bit different. What about memory leaks, too many parts (this craft crashed my game once), etc.

Or, as always, theres always the user not being experienced enough or just plain dumb or bad at multitasking, etc..

Theres far too many variables here to form a concrete solution.

Thanks for trying, everyone!

[Zhetaan]

@Solis:

At first glance, it looks as though you have too much booster or not enough payload.  You said that you used this launcher for a Mun orbiter, but if you're only going for Kerbin orbit, it appears that you have about twice as much rocket as you need.

[Invader Jim]

1 hour ago, Solis said:

I have another rocket like this just without the outer boosters and I can get that one into orbit very consistently.

There are some fuel lines connecting to the center booster(maybe thats a small difference) and it seems to fully refill the center booster when I decouple them. (Im not sure if that happens on PC)

 

 

Not sure what difference it would make but I like to put a small fuel tank on top of each SRB to feed the center instead of using regular fuel and engines for the boosters.  With the fins and a swivel for the middle engine I can maneuver. One more thing I do for stability if to connect the 3-4 boosters with a strut near the bottom since the decouplers are high. 

[Solis]

7 minutes ago, Invader Jim said:

Not sure what difference it would make but I like to put a small fuel tank on top of each SRB to feed the center instead of using regular fuel and engines for the boosters.  With the fins and a swivel for the middle engine I can maneuver. One more thing I do for stability if to connect the 3-4 boosters with a strut near the bottom since the decouplers are high. 

I like the SRB idea, I didn't use them because then I couldn't feed the center booster but thats a good workaround.

I have it strutted properly at the bottom, just hard to see.

53 minutes ago, Zhetaan said:

@Solis:

At first glance, it looks as though you have too much booster or not enough payload.  You said that you used this launcher for a Mun orbiter, but if you're only going for Kerbin orbit, it appears that you have about twice as much rocket as you need.

Don't you have to get to Kerbin orbit before getting to the Mun, though? Thats what I did, anyways.

[HvP]

Just as an experiment to test something @Solis could you try a variation of your rocket that uses 4 way symmetry instead of 3 way symmetry?

I find that rockets with control surfaces in 3 way symmetry have a tendency to push and pull in odd ways while turning. In 4 way symmetry half of the control surfaces are mainly affecting pitch at any one time, and the other half are mainly affecting yaw. In 3 way symmetry at least two of them are trying to do double duty controlling both pitch and yaw at the same time because at any moment only one fin can ever be parallel to your axes of flight.

The problem is made worse if you have roll control turned on for those fins. Now they are trying to do three things at once and can't possibly compensate that well. As @Kryxal said, I would turn off roll control for those fins at least.

Edited June 6, 2017 by HvP

[Spricigo]

1 hour ago, Solis said:

Also worthy to note that the service bays are very wonky.

 

Ok, that bring new possibilities:

->Are you flying with SAS on and your craft wobbling ? This may cause some disagreement between your probecore and control surfaces/engines to where your rocket should be pointed, since they are effectively pointing in slight different directions. That end in constant 'correction' input away from where you want the rocket to go. If  that is the case flying with SAS off would be enough to solve the issue,  specially if, as Ohm is Futile test suggest, the craft tend to follow prograde without input.

->If the parts inside the Service Bays are clipping outside drag will grab then. It may or may not be enough to make the craft flip. In PC you can see if that is the case with the aerodynamic overlay, but I don't know if that is a thing in PS4 version , so just try to keep the parts well inside the service bay, attach something at the nodes and the rest radially to that central part with enough room to not touch the sides.

 

As other already pointed, you can reach orbit with much less than what you are using, and even a 'heavy' satellite should have plenty of fuel to reach anywhere within Kerbin SoI from LKO. While I didn't rule out an issue with that particular rocket, I suspect that some of the problem may be lack of experience in piloting/design. Don't worry, who don't know can learn and who know can teach.

I suggest you to try a satellite like that: service bay with probecore, 2x z-100 bateries, [whatever scientific instrument the contract asks for] (nothing bigger then a mystery goo canister in this satellite, yet], nose cone for aerodynamic purposes, FL-t400 fuel tank, 4x solar panel around the tank and a terrier engine. That would be ~3km/s deltaV with good TWR. Below that a stack decoupler, a Thumper Solid Rocket booster and 4 AV-T1 winglets. Limite the thurst of the Thumper to 70%(no need to be very precise) Use the rotate tool to tilt the entire rocket in the VAB (lets say 10°) and add Launch Stability Enhancers.

Launch it and see how it goes, don't try to steer it, just let if fly and stage as needed. If you go to orbit good, if not revert to VAB, adjust and try again. If too shallow decrease initial inclination or increase the thrust, If too steep the other way around. That will result in a functional satellite/launcher but its not highly optimized, you may stop there or keep reducing mass until you have 'just enough' to get the job done.

 

[Zhetaan]

2 hours ago, Solis said:

Don't you have to get to Kerbin orbit before getting to the Mun, though? Thats what I did, anyways.

Oh!  I was given to understand that you had a different payload for your Mun orbiter.  My apologies.

[Solis]

3 hours ago, Spricigo said:

I suggest you to try a satellite like that: service bay with probecore, 2x z-100 bateries, [whatever scientific instrument the contract asks for] (nothing bigger then a mystery goo canister in this satellite, yet], nose cone for aerodynamic purposes, FL-t400 fuel tank, 4x solar panel around the tank and a terrier engine. That would be ~3km/s deltaV with good TWR. Below that a stack decoupler, a Thumper Solid Rocket booster and 4 AV-T1 winglets. Limite the thurst of the Thumper to 70%(no need to be very precise) Use the rotate tool to tilt the entire rocket in the VAB (lets say 10°) and add Launch Stability Enhancers.

Launch it and see how it goes, don't try to steer it, just let if fly and stage as needed. If you go to orbit good, if not revert to VAB, adjust and try again. If too shallow decrease initial inclination or increase the thrust, If too steep the other way around. That will result in a functional satellite/launcher but its not highly optimized, you may stop there or keep reducing mass until you have 'just enough' to get the job done.

 

I did exactly as you said and I was able to get into a fairly decent orbit with it not tilted at launch but it drifted west a little. Tilted it just became a ballistic missile no matter what.

Ill see if I can get it into the required orbit. Edit: I have no idea how to get into that orbit. I can get my AP and PE to 12k km (only with the maneuver nodes, don't know if theres enough fuel it was pretty low) but can't get them lined up at all. 

(Sorry, I aaccidentally hit send on an incomplete message before this edit)

Edited June 7, 2017 by Solis

[Spricigo]

Wait a minute... Did you just said you somehow managed to get into orbit (any orbit)  launching vertically and not steering?!?!! 

What I suggested is to have a rocket,  in the VAB,  looking like that:

Spoiler

Then press space and it will steer by itself. Not touching WASD or using SAS.  With the correct combination of thrust and initial inclination,  the first stage would be enough to put your apoapsis outside the atmosphere (somewhere between 70km and 150km) with fairly high horizontal velocity.  At this point either a) wait for apoapsis and circularize or b) keep burning until your trajectory reach the desired orbit height. Any way from that point is basic orbital maneuvers * until you reach the orbit the contract asks. 

I will run some tests to confirm I didn't botched the calculations when suggesting the design.  But seems very similar to others design I had used, and shared,  without any problem. 

 

*burn prograde to raise the opposite side of the orbit,  burn retrograde to lower the opposite side of the orbit,  burn normal/antinormal at the ascending/descending node to change inclination. 

 

[Solis]

2 minutes ago, Spricigo said:

Wait a minute... Did you just said you somehow managed to get into orbit (any orbit)  launching vertically and not steering?!?!! 

I launched vertically until the SRB ran out of fuel and burned towards the horizon.

 

3 minutes ago, Spricigo said:

What I suggested is to have a rocket,  in the VAB,  looking like that:

  Hide contents

 

On PS4 I can only rotate the rocket at set intervals, so I don't believe that I can match that angle unless there is a different way to rotate that I don't know about.

 

6 minutes ago, Spricigo said:

*burn prograde to raise the opposite side of the orbit,  burn retrograde to lower the opposite side of the orbit,  burn normal/antinormal at the ascending/descending node to change inclination. 

 

I guess I will have to work on inclining my orbit but to be honest ive not had a lot of patience with this game recently.

[HvP]

20 minutes ago, Solis said:

On PS4 I can only rotate the rocket at set intervals, so I don't believe that I can match that angle unless there is a different way to rotate that I don't know about.

If you look down in the bottom left side of the VAB layout you'll see a yellow hexagon with a dot in the middle (it's under the button for your center-of-lift marker that looks like a small yellow wing). Push the hexagon button and it will turn off angle snap so you should be able to finely adjust your part placement and rotation. Also I understand that LB and RB move the parts in fine control mode (you may have to have the rotate gizmo selected to make use of this.)

I'm sorry you're getting frustrated with the game, but remember it is rocket science so try not to feel bad. There is a learning curve and it really does take some practice. No one will judge you if you feel like taking a break from it for a bit though. Maybe watch some Youtube vids about KSP. I hear that Scott Manley's channel is a good one to start with (but be careful of old tutorials, because the game's mechanics have changed over the years.)

Edited June 7, 2017 by HvP

[Spricigo]

Ok, I indeed overestimated the deltaV and the power of the thumper a bit. What I did that worked:

Spoiler

 

5° tilted east. If Im not mistaken that is yaw rigth once to you.

Pre-launch:SAS OFF, throtle 100%

Don't actively steer, let it fly itself.

Just after the SRB burnout activate SAS and point it just below prograde,(2-3° is enough).  Once SRB burned out activate next stage and raise the apoapsis to 85-90km.

Cut the engine and coast to apoapsis, my rocket actualy fliped at this point but the apoapsis stayed well outside the atmosphere. Just wait until you reach 50km and you can reorient the rocket without effort.

Around 65km start to burn to circularize, point 5° below horizont and watch the apoapsis in the map mod (I hope you can control the craft on map mode also in PS4) If it start to move away from your rocket reduce the throttle (or even cut the engine) you dont want to raise it too much at this time. you should archive  orbit around 80-100km and have enough deltaV to complete the mission (~2km/s). I raised my orbit to 12kmx12km than changed inclination by 15° and still had 500m/s left.

 

If the upper stage flipping bother you ad 2 basic fins neard the terrier engine and use 4 at the bottom of the SRB. You may also try a pair or hammer radialy attached to give just a little extra boost however (1) it will increase the rocket cost by 15-20%; (2)it may skew the ballance off weigh, thrust and initial angle.

 

 

1 hour ago, Solis said:

I launched vertically until the SRB ran out of fuel and burned towards the horizon.

well, that is like to make a 90° turn, we want instead to cut the corner . Starting to turn rigth from the launchpad and progressively point to the horizont, that way we reduce drag loss (since we expose a lower area to the airflow) and our trajectory will be shorter.

Edited June 7, 2017 by Spricigo