Space Shuttle Ultra development thread

[DaveS]

Glad to know it works. I'm not sure why this problem suddenly came up; as far as I can tell, the old code should have worked fine.

Now maybe someone could make the MLP stop moving when the SSMEs are thrusting prior to T0?

 

[Urwumpe]

Now maybe someone could make the MLP stop moving when the SSMEs are thrusting prior to T0?

Shouldn't the MLP be stationary regardless of the SSME thrust? Can you get a screenshot with the force vector arrows, maybe your symptoms are not related to the SSMEs... did not look into the MLP code for a while.

 

[DaveS]

Shouldn't the MLP be stationary regardless of the SSME thrust? Can you get a screenshot with the force vector arrows, maybe your symptoms are not related to the SSMEs... did not look into the MLP code for a while.

Force vector screenshot attached and yes that is what I mean. The MLP is visibly moving northward during the ~6 seconds the SSMEs are firing.

 

[Urwumpe]

Force vector screenshot attached and yes that is what I mean. The MLP is visibly moving northward during the ~6 seconds the SSMEs are firing.

Does not make sense. The MLP is moving without a force. Seems like a tiny Orbiter Engine bug. What is the state of the MLP in the CTRL+I dialog?

 

[Donamy]

I do not get the MLP movement at launch


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Dennis,

Can you look at the launch sequence and get some of those problems fixed ?

 

[Urwumpe]

I do not get the MLP movement at launch


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Dennis,

Can you look at the launch sequence and get some of those problems fixed ?

I will start later this evening, about 2-3 hours, would be simpler if you can compile a summary of all known problems here, I am sure SiameseCat could also find use for it.

I still wait for my little family to confirm that they arrived home intact.

 

[Donamy]

Off hand,

1. jumping off the pad, needs to be slowed down
2. engine gimbal wiggle
3. roll should be quicker
4. SRB smoke stops just before SEP, and SRB rotation not implimented

That would take care of the imediate concerns.

 

[DaveS]

Does not make sense. The MLP is moving without a force. Seems like a tiny Orbiter Engine bug. What is the state of the MLP in the CTRL+I dialog?

Keeps bouncing between ACTIVE and IDLE. Goes to rock-soild IDLE status at T0 when the holddown bolts are blown.

 

[Urwumpe]

Keeps bouncing between ACTIVE and IDLE. Goes to rock-soild IDLE status at T0 when the holddown bolts are blown.

I'll investigate this, maybe I can do some VESSELSTATE magic to fix this.

 

[Donamy]

Hope the family made it home alright.

 

[Urwumpe]

Offtopic:

Hope the family made it home alright.

They did... they just forgot to phone after they arrived. :lol: And complained about so many people in Germany using the same day as they for returning home from the New Year holidays.

Now, my girlfriend can again discuss with our daughter how early she has to go to sleep...

 

[SiameseCat]

DaveS: Are you using some kind of plugin that transfers forces from attached child vessels to whatever they're attached to? Normally, the SSU vessel is a child attachment of the MLP vessel, so the MLP should not experience any force from the shuttle.


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Off hand,

1. jumping off the pad, needs to be slowed down
2. engine gimbal wiggle
3. roll should be quicker
4. SRB smoke stops just before SEP, and SRB rotation not implimented

That would take care of the imediate concerns.

What should the roll rate be? I'm currently using a value of 8 deg/sec.
I can fix this and the engine wiggle problems.

 

[Poscik]

Shuttle's roll program for 51.6° inc. takes 7-8 seconds, so roll rate is something about 13°/sec.

 

[DaveS]

DaveS: Are you using some kind of plugin that transfers forces from attached child vessels to whatever they're attached to? Normally, the SSU vessel is a child attachment of the MLP vessel, so the MLP should not experience any force from the shuttle.

Whatever caused the problem is gone now. Must have been a plug-in as I deactivated all the plug-ins except for OrbiterSound, ExtMFD and CRTMFD.

 

[Donamy]

Slight problem, a light on the crew access arm does not rotate with the arm.

 

[DaveS]

Slight problem, a light on the crew access arm does not rotate with the arm.

Taken care of.

 

[SiameseCat]

The roll rate and SSME wiggle should be fixed now.

 

[Donamy]

The SSME wiggle is gone, just alittle SRB wiggle now. The stack should be stable during the roll.


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Would moving the roll aim point slightly forward if the CG eliminate the wabble ?

 

[Urwumpe]

Would moving the roll aim point slightly forward if the CG eliminate the wabble ?

Likely not, aiming ahead of the CG solves other control problems and makes the shuttle more effective.

I think the problem is more, that we expect a constant roll rate during the maneuver. Actually, we should have a tapered function for calculating the commanded roll rate, this would make the commands smoother as we have less overshooting.

 

[Donamy]

I know we should. Can we ?