Shuttle Reentry Computer problem

lolypoly381N

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Hello,

I was playing SSU and after deorbit burn, I time-warped to 5 min before entry interface. However, once I get into EI, everything seems to be going well until a few minutes into Entry. The shuttle bug goes below the vertical entry guidance course. And then later, the bug somehow goes into the front of the next Entry TRAJ and then goes backward. I check on the map MFD and the shuttle is somewhere over Texas. Later, I wanted to see whether the computer will guide me to the HAC, where I can switch to CSS, but around Mach 4, the shuttle begins to pitch up drastically and then stalls way before KSC.

What am I doing wrong here?

I used the deorbit and entry checklist: https://wiki.flightgear.org/Flying_...on_Advanced#Deorbit_Burn_preparation_and_Burn . I skipped some of the switches which didn't work for SSU.
 

lolypoly381N

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I don't know whether this is because I am flying STS 107 which I believe is the last Columbia flight before it burned up in reentry. The only difference this time is that the shuttle just started spinning. In the photo below, it shows how the shuttle lost control, and on the Entry TRAJ, it shows that the shuttle is on minimal energy.

1643197541015.png
 

STS

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Seems that you are not doing the deorbit burn correctly. You should be at 400000 ft (EI) and a RTGO of 4472 nm IIRC.

Take a look at this thread:

 

STS

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Oh, so how do I specify the deorbit burn location and the delta V in the deorbit planner?
That is your output, wich is calculated by Solver (an Excel or LibreOffice Calc feature). Cannot remember how it was used exactly, but here are some handwritten notes, translated from spanish.

Cell target C25

By changing cells C9

Conditions according to screenshot "solver1"

Continue several times to confirm that the results are the same (through iterations).

Run solver again

Cell target C26

By changing cells C19

Continue several times to confirm that the results are the same.

Correct distance result to be able to see it on the MAP MFD. (Distance given minus maximum displayable distance by MFD= a | D = maximum displayed distance - a)

a=21567-19990=1577
D=19990-1577=18413

Best regards,
 

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lolypoly381N

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Okay, so I have managed to get a deorbit burn where I enter EI at 400k ft alt and I am roughly 8250 km away from Edwards. Initially, everything happens accordingly, until later when the AoA (which was slowly decreasing from around 210-230 kft) gets too low, about 30 degrees when the shuttle spins out of control. I don't understand what is happening. Please help.

Kind regards
 
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DaveS

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Okay, so I have managed to get a deorbit burn where I enter EI at 400k ft alt and I am roughly 8250 km away from Edwards. Initially, everything happens accordingly, until later when the AoA (which was slowly decreasing from around 80 km) gets too low, about 30 degrees when the shuttle spins out of control. I don't understand what is happening. Please help.

Kind regards
Did you retarget from KSC to EDW using SPEC050? You need to do that prior to the de-orbit so that the GPCs know that you want to land at EDW and not KSC. That is ITEM 41+45 EXEC on the keyboard.
 

lolypoly381N

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1644084181622.png

This is me with I am entering EI. All is good so far.

1644084586135.png

The angle of attack is slowly reducing but still within alpha modulation. Shuttle reentry course looks good.
1644084885965.png

AoA is way too low.
1644085090819.png
Now the shuttle spins out of control
 

lolypoly381N

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Did you retarget from KSC to EDW using SPEC050? You need to do that prior to the de-orbit so that the GPCs know that you want to land at EDW and not KSC. That is ITEM 41+45 EXEC on the keyboard.
Yes, I have targeted Edwards. The computer does a right-hand roll reversal to Edwards. Now I am beginning to think that the Shuttle's AoA is reducing because of the aerodynamic forces as the shuttle gets deeper into the atmosphere.

1644085507050.png
 
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