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[1.2.2] Space Shuttle System new release 26.01.2017

DECQ

By DECQ
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Bosun

Bosun

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The problem I run into, Rigel, is that attempting to follow this outline, even remotely emulate, will either cause the craft to burn up in the upper atmosphere, or cause it to correct for COM forward, which is the tail end of the craft.  

There is no scenario I've been able to emulate in RSS with RO where I hit 104k-ish and while reducing speed.  What ends up happening, is I will accelerate towards the planet even at oblique angles until I hit around 103k altitude, and then immediately, the ship will begin to over heat, and before I can drop below 7000 m/s, I've burned up at around 100k.  

Is there a trick I'm missing in RSS / RO?  I currently have no craft that  begins deceleration before 103k.   Until that bar, they all accelerate regardless of shape or entry angle.   Is that correct behavior?  I'm beginning to think my RO/RSS atmosphere may be the problem, as I see others posting with the shuttle apparently working, so I'm thinking it's got to be something other than the Shuttle itself.  

Except for the COM thing, but I think I can fix that creatively with excess ballast weight.

 

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m4gus88

m4gus88

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I had the same problem, but yesterday I finally managed to reenter. The solution was some lead ballast (~15 tons) clipped into the nose. It's still not completely stable, and flips if I try large pitch angles, but MechJeb can steadily hold it at 30 degrees, and it comes down like a charm, doing lots of skips in the upper atmosphere. Then, when I'm under 5 Mach, I can switch to SAS and manual control, and it's quite easy to maneuver.

It doesn't work without the lead ballast though, so for the RO configs I'd recommend making the nose heavier a bit, and reducing the mass of the engine mount by the same amount. At least to bring the CoM in front of the CoL.

Alternatively, you can try removing OMS fuel for the entry, that will also bring the CoM forward, but you'll need some fuel for holding the AoA.

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Rigel Kerman

Rigel Kerman

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Thanks for the good idea @m4gus88, regarding the CoM vs CoL. this not something I've looked at but it makes a lot of sense that this could be contributing to the difficulty. I've generally been making my decents with significant OMS fuel which no doubt has impacted the CoM position. 

I plan to experiment with a heavier nose with and without OMS fuel. Let me know if anyone else also tries this. 

Additionally it turns out my RSS did not have FAR installed correctly so that could be part of my problem as well. 

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m4gus88

m4gus88

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If you want to stay realistic, then OMS fuel on the nose won't help on reentry, because AFAIK the shuttle vented all fuel from the nose at entry interface, and only used the aft thrusters for holding AoA.
(I'm not sure why it did that, but best guess, they didn't want hypergolic fuel in a place that gets hit hard by reentry heating)

Another thing is, you wouldn't want to move the CoM too much ahead of the CoL, as it will make it "too stable", and you'll lose maneuverability (it will also make it more difficult to hold a high AoA). I just put enough ballast in the nose to move it just a little ahead. Of course this will make it less stable in the lower atmosphere, but it's supposed to be a flying brick anyway, right? :)

After a bit of research, I found this:
https://spaceflight.nasa.gov/shuttle/reference/shutref/structure/fwdfuselage.html
Looks like the real shuttle had around 2 tons of total ballast in the nose section.

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DrLicor

DrLicor

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@m4gus88, it is highly possible that the CoM at the moment isn't on the right place. 
So I think it's just a matter of balancing the thing by playing with the mass over the whole craft. Ofsett thing a bit. Just what you do now with the ballast thing. 
 

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Slainte Maith

Slainte Maith

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On 5/24/2017 at 3:12 AM, m4gus88 said:

Did you install Rigel's Realism Overhaul patch?

If not, go back a page or two, the download link is in one of his posts.

I did this.  Then the OMS and RCS engines vanished from my part list and became invalid on my .craft.  Am I using a wrong version of ...something?

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radio

radio

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14 hours ago, Slainte Maith said:

I did this.  Then the OMS and RCS engines vanished from my part list and became invalid on my .craft.  Am I using a wrong version of ...something?

Sounds like you changed the files in the wrong location. Assuming you are using "Rigel's Realism Overhaul patch". Those files are patches, not entire configs, hence they corrupt your craft. These patches have to be placed in GameData -> RealismOverhaul -> RO_SuggestedMods -> SPACE_SHUTTLE_SYSTEM.

 

 

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Slainte Maith

Slainte Maith

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Latest issue (and since we're getting to 'graphical glitches,' the issue list is shrinking...)  I'm using 64 bit, forcing DX11, have more RAM than Jesus, etc...   When you zoom out from the shuttle, the texture turns that brownish tan and gets lines in.

I've had similar issues with E.T.O. for RSS.  

https://goo.gl/photos/6gCmXVzCREdzMWsEA

 

Edited by Slainte Maith
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Cheesecake

Cheesecake

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2 hours ago, Slainte Maith said:

Latest issue (and since we're getting to 'graphical glitches,' the issue list is shrinking...)  I'm using 64 bit, forcing DX11, have more RAM than Jesus, etc...   When you zoom out from the shuttle, the texture turns that brownish tan and gets lines in.

I've had similar issues with E.T.O. for RSS.  

https://goo.gl/photos/6gCmXVzCREdzMWsEA

 

It is the -force-d3d11 which occurs this issue.

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Rigel Kerman

Rigel Kerman

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Regarding the use with realism overhaul, I agree dumping fuel is important to shift the COM closer to the COL for the ship during recently. However, I don't see any way to do this except through an add-on. So I can add ~2 tons to the nose in order to get the COM slightly ahead of the COL when its empty, but we'll need to encourage people to use the add-on as well so they can dump fuel. As a whole the ship looks pretty light relative to its reported dry weight, but I'd like to get it flying steady before scaling up.

I am also beginning to suspect that the RCS thrusters are just too weak relative to realism overhaul. According to Wikipedia, each RCS engine produced 870 pounds of thrust in vacuum, I'll need to covert that to KSP configuration.

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DECQ

DECQ

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46 minutes ago, Rigel Kerman said:

Regarding the use with realism overhaul, I agree dumping fuel is important to shift the COM closer to the COL for the ship during recently. However, I don't see any way to do this except through an add-on. So I can add ~2 tons to the nose in order to get the COM slightly ahead of the COL when its empty, but we'll need to encourage people to use the add-on as well so they can dump fuel. As a whole the ship looks pretty light relative to its reported dry weight, but I'd like to get it flying steady before scaling up.

I am also beginning to suspect that the RCS thrusters are just too weak relative to realism overhaul. According to Wikipedia, each RCS engine produced 870 pounds of thrust in vacuum, I'll need to covert that to KSP configuration.

Why add and remove mass? There is a line in cfg, its very simple to use
CoMOffset = 0.0, 0.0, 0.0
If it is lifted then it will not be necessary to suffer from the mass of the ship.
By the way, an interesting picture, though I do not know how true it is.

Thermal_Blackout_Period01.gif

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radio

radio

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On 5/29/2017 at 1:30 AM, Slainte Maith said:

Silly question: Why is SSRSS in with everything else on the install?  Shouldn't that -not- be there, as (I'm guessing) this isn't stock size?

It isn't. Perhaps you are mistaking SSRSS with SSTU or something else.

 

10 hours ago, DECQ said:

Why add and remove mass? There is a line in cfg, its very simple to use
CoMOffset = 0.0, 0.0, 0.0
If it is lifted then it will not be necessary to suffer from the mass of the ship.
By the way, an interesting picture, though I do not know how true it is.

Thermal_Blackout_Period01.gif

That's pretty much how it goes, that picture. So far I've managed to get into LEO, deorbit and reenter at 40° AoA (using RO/RSS). The only thing I'm lacking is the correct final descent procedure. I find myself loosing control of the vehicle after gradually lowering the pitch for final descent in dense atmosphere (bellow Mach5). Oh, and I had to cheat and increase thrust of SSME's in engine .cfg to get into orbit. Can't seem to have enough Δ V for some reason. Works for now, but It would be nice to keep the realistic specs.

3 hours ago, CassiniPanini said:

Every time I install this mod the wings for the shuttle are missing and I cannot for the life of me find them or fix this problem. Seems to be the only part I am missing. Anyone have any idea whats on the go?

Are you using any of the RO configs for the Shuttle found in this thread?

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DECQ

DECQ

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19 hours ago, radio said:

It isn't. Perhaps you are mistaking SSRSS with SSTU or something else.

 

That's pretty much how it goes, that picture. So far I've managed to get into LEO, deorbit and reenter at 40° AoA (using RO/RSS). The only thing I'm lacking is the correct final descent procedure. I find myself loosing control of the vehicle after gradually lowering the pitch for final descent in dense atmosphere (bellow Mach5). Oh, and I had to cheat and increase thrust of SSME's in engine .cfg to get into orbit. Can't seem to have enough Δ V for some reason. Works for now, but It would be nice to keep the realistic specs.

Are you using any of the RO configs for the Shuttle found in this thread?

And the descent? I showed the center of the mass of the ship.

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radio

radio

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On 5/31/2017 at 2:01 PM, DECQ said:

And the descent? I showed the center of the mass of the ship.

Good (mass) point. :) I will look into it. My center of mass might be a tad off of where it should be. Other than that, I am working on programming ascent and descent profiles for the shuttle. Using kOS. Although MechJeb's smart A.S.S works alright for the purpose.

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