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memyselfandI

MechJeb is broken Completely (1.22)

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Posted (edited)

I'm about fed up with the stupidity of this mod. In the last several hours this mod hasn't been working correctly with ascent guidance. Every zmap satellite I launch keeps crashing back down to Kerbin. Not to mention the fact it doesn't execute  stages on time either. 

Edited by memyselfandI

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diomedea    695

MechJeb works fine, but can't do miracles. One miracle would be being able to steer a zmap launch vehicle without any means of doing. Some of the stock vessels are of really poor design: zmap only has control surfaces and engine gimbals to change attitude, but the first don't work once out of the atmosphere; the second don't without thrusting. Indeed each and every zmap launch sees MechJeb stop completely any attempt at controlling attitude just as altitude goes beyond 70 Km (throttle being at 0% as the required Ap is already met). And while not pointing in the correct direction, MechJeb doesn't throttle (would only make things worse).

You have any means of doing manually what MechJeb can't? I tried at least 10 times without any success, stock zmap simply can't be steered if not using the engine.

Try what I did to verify what I'm telling: add a reaction wheel to the satellite and launch again: now MechJeb can complete the ascent and circularization without problems.

Now, hoping you got how things work, would be honest if you corrected what you kept writing about this add-on, both here and on that other thread.

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On 5/14/2017 at 7:39 AM, diomedea said:

MechJeb works fine, but can't do miracles. One miracle would be being able to steer a zmap launch vehicle without any means of doing. Some of the stock vessels are of really poor design: zmap only has control surfaces and engine gimbals to change attitude, but the first don't work once out of the atmosphere; the second don't without thrusting. Indeed each and every zmap launch sees MechJeb stop completely any attempt at controlling attitude just as altitude goes beyond 70 Km (throttle being at 0% as the required Ap is already met). And while not pointing in the correct direction, MechJeb doesn't throttle (would only make things worse).

You have any means of doing manually what MechJeb can't? I tried at least 10 times without any success, stock zmap simply can't be steered if not using the engine.

Try what I did to verify what I'm telling: add a reaction wheel to the satellite and launch again: now MechJeb can complete the ascent and circularization without problems.

Now, hoping you got how things work, would be honest if you corrected what you kept writing about this add-on, both here and on that other thread.

I will try it right now. Also, the add-on I was talking about involved a more updated version of MechJeb which wasn't posted on the mod section of this or Curse. 

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diomedea    695
9 minutes ago, memyselfandI said:

I will try it right now. Also, the add-on I was talking about involved a more updated version of MechJeb which wasn't posted on the mod section of this or Curse. 

Indeed. Always best to provide version details. I tested with both the 2.6.0.0 version available as main download with MechJeb, and the latest (as of yesterday) devbuild 698.

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linuxgurugamer    5586

Post either a video showing what you are doing, or a series of pics.

Plenty of people use mechjeb without any problem.

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diomedea    695
1 hour ago, memyselfandI said:

Now this is becoming xxxxxxxx. The most used basic unmanned stock vehicle is crashing back down to kerbin! This hasn't happened before, and I'm telling you it's MechJeb. The Comsat LX Stock (With Mod Unmanned before Manned) is crashing back down. 

Would you mind first to confirm that what I suggested works, and the cause is indeed the lack of control with zmap launch?

In the case of Comsat LX, the first stage has 3092 m/s DV (VAC), 2423 m/s DV at sea level. To make orbit from KSC at least 3200 m/s DV are needed. It takes a perfect ascent trajectory to bring it to orbital speed with the tiny engine of the last stage. Mechjeb can be set so to choose a proper ascent trajectory, but takes effort to set it, and some knowledge about what is involved.

Again, it isn't Mechjeb the culprit. You keep blaming something wrongly, and now what is that other add-on (Unmanned before Manned) doing? Do your tests without other stuff that may change how things work, and could be the real cause of your troubles, instead of insisting against all evidence in blaming what isn't.

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Posted (edited)
2 minutes ago, diomedea said:

Would you mind first to confirm that what I suggested works, and the cause is indeed the lack of control with zmap launch?

In the case of Comsat LX, the first stage has 3092 m/s DV (VAC), 2423 m/s DV at sea level. To make orbit from KSC at least 3200 m/s DV are needed. It takes a perfect ascent trajectory to bring it to orbital speed with the tiny engine of the last stage. Mechjeb can be set so to choose a proper ascent trajectory, but takes effort to set it, and some knowledge about what is involved.

Again, it isn't Mechjeb the culprit. You keep blaming something wrongly, and now what is that other add-on (Unmanned before Manned) doing? Do your tests without other stuff that may change how things work, and could be the real cause of your troubles, instead of insisting against all evidence in blaming what isn't.

1 2 3

Edited by memyselfandI

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diomedea    695
15 minutes ago, memyselfandI said:

1 2 3

Sure, I certainly know it can go to orbit. With MechJeb.

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Just now, diomedea said:

Sure, I certainly know it can go to orbit. With MechJeb.

Any thoughts or ideas on setting up a good relay of this with early game tech (Without cheating). Plus, I suck at making rockets/probes.

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diomedea    695
1 minute ago, memyselfandI said:

Any thoughts or ideas on setting up a good relay of this with early game tech (Without cheating). Plus, I suck at making rockets/probes.

Being in career (as you said, early tech) makes for specific choices about what you have unlocked. In my most recent career game I had to wait a lot before the techs allowing to build a decent relay sat were unlocked (though I play at very hard level, so my progress is slower). Actually, you may wish to do specific choices based on what contracts/missions you have that could bring more advantages, and techs allowing unmanned flights aren't all available that early so you may have to go with more manned flights than you would like. At a very minimum, you need solar panels and decent batteries, and clearly some means to control the vessel (probably the small reaction wheel comes before RCS, unless you choose to go for that).

If you need suggestions about building, probably best to open another thread in Gameplay Questions and show what you are doing and what isn't working as you expect, there is plenty of forum members willing to help if you ask.

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Posted (edited)
1 minute ago, diomedea said:

Being in career (as you said, early tech) makes for specific choices about what you have unlocked. In my most recent career game I had to wait a lot before the techs allowing to build a decent relay sat were unlocked (though I play at very hard level, so my progress is slower). Actually, you may wish to do specific choices based on what contracts/missions you have that could bring more advantages, and techs allowing unmanned flights aren't all available that early so you may have to go with more manned flights than you would like. At a very minimum, you need solar panels and decent batteries, and clearly some means to control the vessel (probably the small reaction wheel comes before RCS, unless you choose to go for that).

If you need suggestions about building, probably best to open another thread in Gameplay Questions and show what you are doing and what isn't working as you expect, there is plenty of forum members willing to help if you ask.

Thanks Dio. Also, does the minimum Orbital ascent for this stock vessel apply to other ones as well? 

Edited by memyselfandI

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linuxgurugamer    5586

Trying to get an orbit at 70km is asking for trouble. Always use something higher

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Kerbal101    451

@memyselfandI my suggestions for carrier are:
- rover up some science first
- go for contracts that bring more money at lower time and lower design challenge
- lookup and learn gravity turn
- lookup advantages of different staging types compared to plain 1-stage ascend
- have a stage TWR not less than 1.5 when below 20km on Kerbin, but do not exceed 400m/s vertical speed either (everyone has own style here, though)
- ... always have a parachute and decoupler attached to the capsule and for probes - a fixed basic solar panel.. :)

 

@linuxgurugamer I am the troublemaker then :D  But you're right :)

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39 minutes ago, linuxgurugamer said:

Trying to get an orbit at 70km is asking for trouble. Always use something higher

At the moment (Thanks to another mod) I was able to cheat my way into a stable orbit around Mun. 

9 minutes ago, Kerbal101 said:

@memyselfandI my suggestions for carrier are:
- rover up some science first
- go for contracts that bring more money at lower time and lower design challenge
- lookup and learn gravity turn
- lookup advantages of different staging types compared to plain 1-stage ascend
- have a stage TWR not less than 1.5 when below 20km on Kerbin, but do not exceed 400m/s vertical speed either (everyone has own style here, though)
- ... always have a parachute and decoupler attached to the capsule and for probes - a fixed basic solar panel.. :)

 

@linuxgurugamer I am the troublemaker then :D  But you're right :)

I might try my hand at landing some Kerbals again on Mun. 

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