TORRA Maneuver in SSU v1.25

BenSisko

BenSisko

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STS-92 Docking scenario with ISS v3.0 by Thorton

I first establish the ISS on the R-Bar.
Using the Rendezvous checklist JSC–48072–101 for the UNIV PTG and DAP settings.
Approaching the R-Bar
Code: 
[FONT=Arial][SIZE=1][FONT=Arial][SIZE=1]CONFIG FOR RBAR 
[/SIZE][/FONT][/SIZE][/FONT][LEFT][FONT=Arial][SIZE=1][FONT=Arial][SIZE=1][20B][/SIZE][/FONT][/SIZE][/FONT][FONT=Arial][SIZE=1]
[LEFT][SIZE=1][FONT=Arial][GNC_20__DAP_CONFIG][/FONT][/SIZE]
[/SIZE][/FONT][FONT=Arial][SIZE=1][FONT=Arial][SIZE=1]CRT DAP: A14, B14 – ITEM 1 +1 4 +1 4 EXEC[/SIZE][/FONT]
[/SIZE][/FONT][FONT=Arial][SIZE=1][FONT=Arial][SIZE=1][GNC_UNIV_PTG][/SIZE][/FONT]
[/SIZE][/FONT][FONT=Arial][SIZE=1][FONT=Arial][SIZE=1]TGT ID +2[/SIZE][/FONT]
[SIZE=1][FONT=Arial]BODY VECT +5[/FONT][/SIZE]
[SIZE=1][FONT=Arial]P +270[/FONT][/SIZE]
[SIZE=1][FONT=Arial]Y +0[/FONT][/SIZE]
[SIZE=1][FONT=Arial]OM +0[/FONT][/SIZE]
[/SIZE][/FONT][FONT=Symbol][SIZE=1][FONT=Symbol][SIZE=1]Ö[/LEFT]
[/LEFT]
[/SIZE][/FONT][/SIZE][/FONT][LEFT][FONT=Arial][SIZE=1][FONT=Arial][SIZE=1]ERR TOT - ITEM 23 EXEC ([/SIZE][/FONT][/SIZE][/FONT][FONT=Symbol][SIZE=1][FONT=Symbol][SIZE=1]*[/SIZE][/FONT][/SIZE][/FONT][FONT=Arial][SIZE=1][FONT=Arial][SIZE=1])[/SIZE][/FONT][/SIZE][/FONT][FONT=Arial][SIZE=1]
[SIZE=1][FONT=Arial]Do not initiate Target Track until ESTABLISH RBAR [/FONT][/SIZE][/SIZE][/FONT][FONT=Arial][SIZE=1][FONT=Arial][SIZE=1][20C][/SIZE][/FONT]
[/SIZE][/FONT]

Established on the R-Bar
Code: 
[LEFT][FONT=Arial][SIZE=1][FONT=Arial][SIZE=1]ESTABLISH RBAR [/LEFT]
[/LEFT]
[/SIZE][/FONT][/SIZE][/FONT][LEFT][FONT=Arial][SIZE=1][FONT=Arial][SIZE=1][20C][/SIZE][/FONT][/SIZE][/FONT][FONT=Arial][SIZE=1]
[LEFT][/SIZE][/FONT][FONT=Arial][SIZE=1][FONT=Arial][SIZE=1]A6U FLT CNTLR PWR - ON[/SIZE][/FONT]
[SIZE=1][FONT=Arial]DAP: A/AUTO/VERN(PRI)[/FONT][/SIZE]
[/SIZE][/FONT][FONT=Arial][SIZE=1][FONT=Arial][SIZE=1][GNC_UNIV_PTG][/SIZE][/FONT]
[/SIZE][/FONT][FONT=Arial][SIZE=1][FONT=Arial][SIZE=1]CRT TRK - ITEM 19 EXEC (CUR - [/LEFT]
[/LEFT]
[/SIZE][/FONT][/SIZE][/FONT][LEFT][FONT=Symbol][SIZE=1][FONT=Symbol][SIZE=1]*[/SIZE][/FONT][/SIZE][/FONT][FONT=Arial][SIZE=1][FONT=Arial][SIZE=1])[/SIZE][/FONT][/SIZE][/FONT][FONT=Arial][SIZE=1]
[LEFT][SIZE=1][FONT=Arial]THC: as reqd to get TGT moving towards COAS center, then:[/FONT][/SIZE][/LEFT]
[SIZE=1][FONT=Arial]THC: as reqd to maintain TGT in COAS FOV.[/FONT][/SIZE]
[/SIZE][/FONT]

Configure for TORRA
Code: 
[LEFT][FONT=Arial][SIZE=1][FONT=Arial][SIZE=1]CONFIG FOR TORRA [/LEFT]
[/LEFT]
[/SIZE][/FONT][/SIZE][/FONT][LEFT][FONT=Arial][SIZE=1][FONT=Arial][SIZE=1][21B][/SIZE][/FONT][/SIZE][/FONT][FONT=Arial][SIZE=1]
[LEFT][/SIZE][/FONT][FONT=Arial][SIZE=1][FONT=Arial][SIZE=1]Config DAP A,B to A10,B10[/SIZE][/FONT]
[/SIZE][/FONT][FONT=Arial][SIZE=1][FONT=Arial][SIZE=1][GNC_UNIV_PTG][/SIZE][/FONT]
[/SIZE][/FONT][FONT=Arial][SIZE=1][FONT=Arial][SIZE=1]TGT ID +2[/SIZE][/FONT]
[SIZE=1][FONT=Arial]BODY VECT +5[/FONT][/SIZE]
[SIZE=1][FONT=Arial]P +180[/FONT][/SIZE]
[SIZE=1][FONT=Arial]Y +0[/FONT][/SIZE]
[SIZE=1][FONT=Arial]OM +0[/FONT][/SIZE]
[SIZE=1][FONT=Arial]ERR TOT - ITEM 23 EXEC ([/FONT][/SIZE][/LEFT]
[/LEFT]
[/SIZE][/FONT][LEFT][FONT=Symbol][SIZE=1][FONT=Symbol][SIZE=1]*[/SIZE][/FONT][/SIZE][/FONT][FONT=Arial][SIZE=1][FONT=Arial][SIZE=1])[/SIZE][/FONT][/SIZE][/FONT][FONT=Arial][SIZE=1]
[/SIZE][/FONT][FONT=Arial][SIZE=1][FONT=Arial][SIZE=1]Do not initiate target TRK until INITIATE TORRA [/SIZE][/FONT][/SIZE][/FONT][FONT=Arial][SIZE=1][FONT=Arial][SIZE=1][23A][/SIZE][/FONT]
[/SIZE][/FONT]

Initiate TORRA
Code: 
[LEFT][FONT=Arial][SIZE=1][FONT=Arial][SIZE=1]INITIATE TORRA [/LEFT]
[/LEFT]
[/SIZE][/FONT][/SIZE][/FONT][LEFT][FONT=Arial][SIZE=1][FONT=Arial][SIZE=1][23A][/SIZE][/FONT][/SIZE][/FONT][FONT=Arial][SIZE=1]
[LEFT][/SIZE][/FONT][FONT=Arial][SIZE=1][FONT=Arial][SIZE=1]A6U [/LEFT]
[/LEFT]
[/SIZE][/FONT][/SIZE][/FONT][LEFT][FONT=Symbol][SIZE=1][FONT=Symbol][SIZE=1]Ö[/SIZE][/FONT][/SIZE][/FONT][FONT=Arial][SIZE=1][FONT=Arial][SIZE=1]FLT CNTLR PWR - ON[/SIZE][/FONT][/SIZE][/FONT][FONT=Arial][SIZE=1]
[LEFT][SIZE=1][FONT=Arial]DAP: A10/AUTO/PRI[/FONT][/SIZE]
[/SIZE][/FONT][FONT=Arial][SIZE=1][FONT=Arial][SIZE=1][GNC_UNIV_PTG][/SIZE][/FONT]
[/SIZE][/FONT][FONT=Arial][SIZE=1][FONT=Arial][SIZE=1]CRT TRK - ITEM 19 EXEC (CUR - [/LEFT]
[/LEFT]
[/SIZE][/FONT][/SIZE][/FONT][LEFT][FONT=Symbol][SIZE=1][FONT=Symbol][SIZE=1]*[/SIZE][/FONT][/SIZE][/FONT][FONT=Arial][SIZE=1][FONT=Arial][SIZE=1])[/SIZE][/FONT][/SIZE][/FONT][FONT=Arial][SIZE=1]
[LEFT][SIZE=1][FONT=Arial]A6U THC: +X (up) 20 pulses (approx 1.0 fps) to initiate flyaround, then[/FONT][/SIZE]
[SIZE=1][FONT=Arial]THC: as reqd to maintain ISS in camera FOV[/FONT][/SIZE]
[SIZE=1][FONT=Arial]DAP: B/AUTO/VERN(PRI)[/FONT][/SIZE]
[SIZE=1][FONT=Arial]When[/FONT][/SIZE]
[/SIZE][/FONT][FONT=Arial][SIZE=1][FONT=Arial][SIZE=1][GNC_UNIV_PTG][/SIZE][/FONT]
[/SIZE][/FONT][FONT=Arial][SIZE=1][FONT=Arial][SIZE=1]CRT PITCH ERROR < 90:[/SIZE][/FONT]
[/SIZE][/FONT][FONT=Symbol][SIZE=1][FONT=Symbol][SIZE=1]Ö[/LEFT]
[/LEFT]
[/SIZE][/FONT][/SIZE][/FONT][LEFT][FONT=Arial][SIZE=1][FONT=Arial][SIZE=1]BODY VECT +5[/SIZE][/FONT][/SIZE][/FONT][FONT=Arial][SIZE=1]
[LEFT][SIZE=1][FONT=Arial]P +90[/FONT][/SIZE]
[SIZE=1][FONT=Arial]Y +0[/FONT][/SIZE]
[SIZE=1][FONT=Arial]OM +0[/FONT][/SIZE][/LEFT]
[SIZE=1][FONT=Arial]TRK - ITEM 19 EXEC (CUR - [/FONT][/SIZE][/SIZE][/FONT][FONT=Symbol][SIZE=1][FONT=Symbol][SIZE=1]*[/SIZE][/FONT][/SIZE][/FONT][FONT=Arial][SIZE=1][FONT=Arial][SIZE=1])[/SIZE][/FONT]
[/SIZE][/FONT]

With these commands, the shuttle fails to stop it's rotation on the -R-Bar. Any suggestions on how to complete this manuver?

Ben
[/LEFT]
 
Where does it stop ?
 
It doesn't stop. When the shuttle reaches the -R-Bar, it continues to pitch up until I terminate the scenario. I've been quite impressed with how accurate the CRT MFD UNIV PTG and DAP have worked with the TORVA and RPM but the TORRA seems off.
 
What happens if you enter ITEM 21 before each ITEM 19? After this, you'll have to put the DAP back in AUTO.
 
I've done that. Each time the ITEM 15 (pitch) value is changed I cancel the tracking mode ITEM 21, enter the new value, re-select DAP A or B/Auto/Vern (as per the checklist), then enter ITEM 19. I tried it again last night to no avail.

It seems odd that the UNIV PTG functions perfectly to hold the R-Bar with P = 270, pitch up appropriately when P = 180, but fails to stop the pitch moment when P = 90. Can anyone reproduce this, or is it just me?
 
For what its worth (and I'm not sure its worth anything), when I use the Univ PTG MFD with the Shuttle Fleet, this works perfectly.
 
I haven't been able to reproduce this so far (although I've been using a 1 deg/s pitch rate). Can you post a screenshot of CRT MFD when it reaches the -R bar?
 
I know. The STS-Rendezvous data you provided works perfectly with the v4.2 Shuttle Fleet. I was trying the TORRA with the SSU v1.25 in STS-92 with no joy.

It still seems odd that the UNIV PTG function of the CRT MFD (SSU v1.25) work perfectly for other maneuvers including the TORVA & RPM but I have this glitch with the TORRA not stopping the pitch moment or maintaining the -R-Bar. I'm curious to find if anyone else can reproduce this error or if it's just me?

SC
Just saw your post. Let me re-run the scenario and I'll post the pix.

Thanks!
 
Last edited:
BenSisko said:
It still seems odd that the UNIV PTG function of the CRT MFD (SSU v1.25) work perfectly for other maneuvers including the TORVA & RPM but I have this glitch with the TORRA not stopping the pitch moment or maintaining the -R-Bar. I'm curious to find if anyone else can reproduce this error or if it's just me?
Click to expand...

I think the whole team is now already investigating it... :lol:

I think such problems are one reason more to have a telemetry file format & viewer.
 
It's obviously me! For what its worth, here are the screenshots:
Approaching R-Bar
sts92approachingrbar.png


Configure for TORRA
sts92dapconfigfortorra.png


On -R-Bar
sts92onrbar.png


Seemed to work this time. The only thing I did differently was to leave the DAP in LVLH as I initially approached the R-Bar prior to initiating TORRA.

Thanks to all!

SC, it looks like we'll have a big game tomorrow. While I'm not a big hockey fan (basketball is my game), good luck to ya!

Ben

---------- Post added 02-28-10 at 02:18 PM ---------- Previous post was 02-27-10 at 02:28 PM ----------

One curious occurrence. With the same starting conditions, following the rendezvous, TORRA and docking checklist I've previously noted, I've had two episodes of unprompted pitch and yaw in the shuttle as I approach for docking. I can't consistently reproduce it though. DAP settings & screenshot below:
Code: 
[FONT=Arial][SIZE=1]CONFIG FOR TORRA [/SIZE][/FONT]
[FONT=Arial][SIZE=1][21B][/SIZE][/FONT]
 
[LEFT][SIZE=1][FONT=Arial][FONT=Arial][SIZE=1][FONT=Arial][SIZE=1]Config DAP A,B to A10,B10[/SIZE][/FONT][/SIZE][/FONT]
[FONT=Arial][SIZE=1][FONT=Arial][SIZE=1][GNC_UNIV_PTG][/SIZE][/FONT][/SIZE][/FONT]
[FONT=Arial][SIZE=1][FONT=Arial][SIZE=1]TGT ID +2[/SIZE][/FONT][/SIZE][/FONT]
[SIZE=1][FONT=Arial][SIZE=1][FONT=Arial]BODY VECT +5[/FONT][/SIZE][/FONT][/SIZE][SIZE=1][FONT=Arial]
[SIZE=1][FONT=Arial]P +180[/FONT][/SIZE]
[SIZE=1][FONT=Arial]Y +0[/FONT][/SIZE]
[SIZE=1][FONT=Arial]OM +0[/FONT][/SIZE][/LEFT]
 
[SIZE=1][FONT=Arial]ERR TOT - ITEM 23 EXEC ([/FONT][/SIZE]
[LEFT][/FONT][/SIZE][FONT=Symbol][SIZE=1][FONT=Symbol][SIZE=1]*[/SIZE][/FONT][/SIZE][/FONT][FONT=Arial][SIZE=1][FONT=Arial][SIZE=1])[/SIZE][/FONT][/SIZE][/FONT]

[FONT=Arial][SIZE=1][FONT=Arial][SIZE=1]Do not initiate target TRK until INITIATE TORRA [/SIZE][/FONT][/SIZE][/FONT][FONT=Arial][SIZE=1][FONT=Arial][SIZE=1][23A][/SIZE][/FONT][/SIZE][/FONT][/LEFT]

 
 
 
[LEFT]INITIATE TORRA [/FONT][/SIZE][/LEFT]
 

[LEFT][FONT=Arial][SIZE=1][FONT=Arial][SIZE=1][23A][/SIZE][/FONT][/SIZE][/FONT]
 
[LEFT][FONT=Arial][SIZE=1][FONT=Arial][SIZE=1]A6U [/SIZE][/FONT][/SIZE][/FONT][/LEFT]
[/LEFT]

 
 
 
 
 

[LEFT][FONT=Symbol][SIZE=1][FONT=Symbol][SIZE=1]Ö[/SIZE][/FONT][/SIZE][/FONT][FONT=Arial][SIZE=1][FONT=Arial][SIZE=1]FLT CNTLR PWR - ON[/SIZE][/FONT][/SIZE][/FONT][/LEFT]

 

[SIZE=1][FONT=Arial][LEFT][SIZE=1][FONT=Arial]DAP: A10/AUTO/PRI[/FONT][/SIZE]
[/FONT][/SIZE]

[/LEFT]

 
 

[LEFT][FONT=Arial][SIZE=1][FONT=Arial][SIZE=1][GNC_UNIV_PTG][/SIZE][/FONT][/SIZE][/FONT]

[LEFT][FONT=Arial][SIZE=1][FONT=Arial][SIZE=1]CRT TRK - ITEM 19 EXEC (CUR - [/SIZE][/FONT][/SIZE][/FONT][/LEFT]


[/LEFT]

 
 
 
 
 

[LEFT][FONT=Symbol][SIZE=1][FONT=Symbol][SIZE=1]*[/SIZE][/FONT][/SIZE][/FONT][FONT=Arial][SIZE=1][FONT=Arial][SIZE=1])[/SIZE][/FONT][/SIZE][/FONT][/LEFT]

 

[SIZE=1][FONT=Arial][LEFT][SIZE=1][FONT=Arial]A6U THC: +X (up) 20 pulses (approx 1.0 fps) to initiate flyaround, then[/FONT][/SIZE]

[LEFT][SIZE=1][FONT=Arial]THC: as reqd to maintain ISS in camera FOV[/FONT][/SIZE]
[LEFT][SIZE=1][FONT=Arial]DAP: B/AUTO/VERN(PRI)[/FONT][/SIZE]
[SIZE=1][FONT=Arial]When[/FONT][/SIZE][/LEFT]
[/LEFT]

[/FONT][/SIZE]

[/LEFT]

 
 

[LEFT][FONT=Arial][SIZE=1][FONT=Arial][SIZE=1][GNC_UNIV_PTG][/SIZE][/FONT][/SIZE][/FONT]

[LEFT][FONT=Arial][SIZE=1][FONT=Arial][SIZE=1]CRT PITCH ERROR < 90:[/SIZE][/FONT][/SIZE][/FONT]
[LEFT][FONT=Symbol][SIZE=1][FONT=Symbol][SIZE=1]Ö[/SIZE][/FONT][/SIZE][/FONT][/LEFT]
[/LEFT]


[/LEFT]

 
 
 
 
 

[LEFT][FONT=Arial][SIZE=1][FONT=Arial][SIZE=1]BODY VECT +5[/SIZE][/FONT][/SIZE][/FONT][/LEFT]

 

[SIZE=1][FONT=Arial][LEFT][SIZE=1][FONT=Arial]P +90[/FONT][/SIZE]

[LEFT][SIZE=1][FONT=Arial]Y +0[/FONT][/SIZE]
[LEFT][SIZE=1][FONT=Arial]OM +0[/FONT][/SIZE][/LEFT]
[/LEFT]
[/FONT][/SIZE]

[/LEFT]

 

[SIZE=1][FONT=Arial][LEFT][SIZE=1][FONT=Arial]TRK - ITEM 19 EXEC (CUR - [/FONT][/SIZE][/FONT][/SIZE][/LEFT]
[SIZE=1][FONT=Arial]
 
[LEFT][/FONT][/SIZE][FONT=Symbol][SIZE=1][FONT=Symbol][SIZE=1]*[/SIZE][/FONT][/SIZE][/FONT][FONT=Arial][SIZE=1][FONT=Arial][SIZE=1])[/SIZE][/FONT][/SIZE][/FONT][/LEFT]

sts92rbarerror.png


Could it be a late transition of the DAP from A/Auto/Vern to B/Auto/Vern? It may be me again but I'm curious to see if anyone else has seen this.​
 
Last edited:
At what point does the 'unprompted pitch and yaw' start? When the shuttle reaches the docking attitude or while it is still pitching?

If this appears again, try to get a screenshot of just the CRT MFD. The main thing I'm interested in looking at the ERR values on the UNIV PTG display.
 
SC,
Check out the screenshot above. That was taken during the spin. It occurrs when the Shuttle is on the -R-Bar ~250 meters out from the docking port.
 
Does the shuttle remain in a stable attitude for some time before spinning? If so, this is really odd, because I would have expected any spin to start while the shuttle was rotating into a new attitude.
 
BenSisko said:
Could it be a late transition of the DAP from A/Auto/Vern to B/Auto/Vern? It may be me again but I'm curious to see if anyone else has seen this.​
Click to expand...
Could you try doing the TORRA completely on the A DAP? Considering that we don't have the correct SPEC 20 DAP CONFIG implemented, I'm uncertain on whether the B DAP actually works or not. I tend to keep the DAP on A due to this.
 
SC & Dave S,
Just ran the scenario again. I key in all the Spec 20 values (see middle screenshot Config for TORRA). Using B DAP after initiating TORRA with no problem. I flew closer to the range parameters in the checklist. I'll keep working this and will post UNIV PTG screenie

SC, Good game, Eh!
 
Congrats to the Canucks !!:cheers:
 
Figured out the spinning. In testing the scenario, I inadvertently depleted the RCS propellant (6 to be specific). It seems you still get the sound of the RCS firing but an asymmetric thrust, thus the spin. As I got better at flying the approach to R-Bar, I conserved fuel and averted the spin.
 
BenSisko said:
Figured out the spinning. In testing the scenario, I inadvertently depleted the RCS propellant (6 to be specific). It seems you still get the sound of the RCS firing but an asymmetric thrust, thus the spin. As I got better at flying the approach to R-Bar, I conserved fuel and averted the spin.
Click to expand...
Actually, what you depleted was the Forward RCS(FRCS) propellant. For now the Aft RCS(ARCS) shares the same propellant tank with the OMS. In the real orbiters the ARCS propellant tanks are independent from the OMS tanks.

So you were flying on ARCS jets alone
 
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