Space Shuttle Ultra 1.25 Revision B development

[Urwumpe]

How was the original CRTMFD font bitmap generated? I'd like to try out a few fonts just see which ones generate the best match.

I used a freeware tool for font maps, from the Rogue-like game development world.

 

[DaveS]

I used a freeware tool for font maps, from the Rogue-like game development world.

Managed to find this software: http://www.codehead.co.uk/cbfg/

 

[Urwumpe]

Managed to find this software: http://www.codehead.co.uk/cbfg/

Yes, that looks similar to what I used.

 

[DaveS]

Yes, that looks similar to what I used.

Well, for me it only comes out as garbled data in CRTMFD after a recompile of the sources.

 

[Urwumpe]

Well, for me it only comes out as garbled data in CRTMFD after a recompile of the sources.

What kind of garble? Wrong antialias settings?

 

[DaveS]

What kind of garble? Wrong antialias settings?

NO, just garbage symbols where the text looks like some alien cryptic symbols. I have attached a screenshot of the problem. Display is UNIV PTG.

I have also attached JPG version of the DEU_Raw.bmp file I have generated with the tool I found.

 

[Urwumpe]

Did you ensure the bitmap has the same dimensions as the original? I can't check it, but the number of characters and the size looks strange.

 

[DaveS]

Did you ensure the bitmap has the same dimensions as the original? I can't check it, but the number of characters and the size looks strange.

Original has the dimensions 288x528, while the new one has the dimensions 256x512.

I guess we just need to find the correct settings for the program.

 

[SiameseCat]

The drawing code works by copying the relevant section of the bitmap into the MFD screen, so the new bitmap has to be identical to the original (same dimensions, same character order).

 

[DaveS]

Well, I'm back investigating why we don't have a proper looking SRB sep and I have discovered that the aft BSM thruster positions and directions are seriously off. I have corrected this on the LSRB but then I noticed something weired, the aft BSMs made the booster spin around it's axis(the longitudinal axis, Y).

I am troubleshooting this now. My main theory is that the lone single aft BSM is responsible for the spinning. I have made it part of the main clustered group of aft BSMs to see how this affects the booster's behavior.

---------- Post added at 03:48 AM ---------- Previous post was at 03:12 AM ----------

OK, so the lone aft BSM is not to blame for the spin along the longitudinal axis. Seems like it's the grouped BSMs.

---------- Post added at 04:37 AM ---------- Previous post was at 03:48 AM ----------

Can someone translate this into rotational angles I can use in GMAX:

Time to drag up this again as I feel it should be fixed before we make a public release again.

I have done some research. The real FWD BSMs for the STS-130 SRBs burned for 3.1 seconds(ignition at 127.3 seconds, final burnout at 130.4 seconds).

Ours(well mine) burn for less than 1 second! Hmmm, could have we have the wrong numbers for the BSMs?

 

[Urwumpe]

Ours(well mine) burn for less than 1 second! Hmmm, could have we have the wrong numbers for the BSMs?

I have the thrust profile of the BSMs from motor test data, which all say that the BSMs should burn for approx 1 second. 3 seconds would be far out. would also need a nuclear specific impulse than to get so much thrust out of the fuel mass. so, unless the BSMs changed since 1991, I would trust the motor test data more.

 

[Donamy]

maybe they continue burning for abit after sep ?

 

[Urwumpe]

maybe they continue burning for abit after sep ?

They start burning already only after sep. And solid rocket motors don't stop abruptly, but keep on producing a little bit of residual thrust as long as there are fuel residuals.

 

[DaveS]

I have the thrust profile of the BSMs from motor test data, which all say that the BSMs should burn for approx 1 second. 3 seconds would be far out. would also need a nuclear specific impulse than to get so much thrust out of the fuel mass. so, unless the BSMs changed since 1991, I would trust the motor test data more.

Well, here's two screengrabs from the RH-inboard SRB camera, one at BSM ignition and one at burnout. Notice the time tags in the upper-right corner.

 

[Urwumpe]

Well, here's two screengrabs from the RH-inboard SRB camera, one at BSM ignition and one at burnout. Notice the time tags in the upper-right corner.

The second shows just residuals, the thrust should be already less than 5% at this point.

 

[DaveS]

The second shows just residuals, the thrust should be already less than 5% at this point.

OK. So any idea on why our SRBs starts spinning thanks to the BSMs? Are the positions and angles off?

If someone could translate this for me into GMAX usable terms, I could verify the positions and angles:

"eparation motors shall be installed in a forward SRB position (nose cone frustum) and
in an aft position (aft skirt). At both the forward and aft locations there shall be a cluster
of four BSMs. At both locations, the thrust vector of the BSM cluster shall be parallel
! 4° to a plane containing the SRB centerline which is rotated 20° about the centerline
from the SRB +Z axis toward the ET (Figure 3.2.1.1.9.1.1.3). The thrust vector of the
forward cluster shall pass within 2.6 inches of the SRB centerline. The thrust vector of
the aft cluster shall be offset 1.95 ± 3.9 inches from the SRB centerline toward the ET
in a direction normal to the 20° plane. In addition, the thrust vector of each cluster shall
be pitched, in the 20° plane, 40 ± 4° from the SRB Y-Z plane; the forward cluster shall
be pitched forward and the aft cluster shall be pitched aft."

 

[Urwumpe]

Shouldn't they be spinning? Also about the orientation, just use standard rotation matrices for the vectors.

Also, according to the bottom drawing, there should be a slight tumble, since the average thrust vector is off-CoG.

 

[DaveS]

Shouldn't they be spinning?

Maybe, but certainly not at 110°/s! That is what I get! The spin-rate I estimate from the SRB on-board cameras are far lower, at around 15°/s.

Also about the orientation, just use standard rotation matrices for the vectors.

Well, my math skills are sub-par, hence the need for a translation.

 

[Urwumpe]

Maybe, but certainly not at 110°/s! That is what I get! The spin-rate I estimate from the SRB on-board cameras are far lower, at around 15°/s.

The thrust of the BSMs shouldn't be enough for 110°/s, unless we have terribly wrong PMIs now.

Well, my math skills are sub-par, hence the need for a translation.

Is not that hard, I can calculate that in SciLab, but you would have to wait some time. I spend the whole week doing such transformations back and forth different coordinate systems at work, and would really like getting some fresh air...

 

[DaveS]

The thrust of the BSMs shouldn't be enough for 110°/s, unless we have terribly wrong PMIs now.

Well, I ran an MC integration using ShipEdit on the left-hand SRB and plugged in the new PMI and cross section values, with no change at all.

I have attached a screenshot of the LH SRB with the thrust vector activated. Does it look good to you?