Project AMSO For Dummies v0.6

[Shifty]

I recently played through the the AMSO Apollo 11 simulation. I noticed that, while the documentation for AMSO is comprehensive and thorough, there is no "walkthrough" which leads you step-by-step through the simulation. And some of the systems (e.g. mission audio, time acceleration) are a little opaque. There are an excellent set of pilot's reference cards on ACSoft's website, but they're in French. I ran them through an on-line translator, and was able to make limited use of them, but the translation is garbled and the cards' beautiful formatting is pretty destroyed.

So, I decided to work on a set of easily printable step-by-step checklists in English for AMSO. They're modeled after the checklists included in the official Orbiter documentation. This is a first draft, but I wanted to present them and hopefully get some feedback before continuing. Let me know what you think.

 

[dgatsoulis]

I like it, very thorough.:thumbup:

It's been a while since my last AMSO mission, so this will be useful when I pick up the ol' AMSO again.
I remember a tutorial by clive bradbury back in '09, but he used IMFD5. It's always good to know how to do something using multiple MFDs.
The link to Clive's walkthrough is [ame="http://orbithangar.com/searchid.php?ID=4170"]here.[/ame] It might be useful for comparison.

 

[Odahs]

I've just started with Orbiter and once I'm done with the basic tutorials I was thinking of AMSO. Looking through as someone who knows nothing at all yet about using AMSO your work looks very promising indeed.

 

[Shifty]

The link to Clive's walkthrough is here. It might be useful for comparison.

I hadn't seen that before. I'll have to reference it within my walkthrough for folks who might prefer IMFD.

 

[Odahs]

Hi Shifty,

Working through AMSO For Dummies

Run into a problem during the LOI burn. Set it up OK, but looking at the orbit MFD my fly-by exactly intersects the moon surface. Hence during the LOI burn I become an ascending Angel. (The first time I did think the moon was getting to look awfully big in the window!)

Not sure at which step I've gone wrong?

 

[Shifty]

Hi Shifty,

Working through AMSO For Dummies

Run into a problem during the LOI burn. Set it up OK, but looking at the orbit MFD my fly-by exactly intersects the moon surface. Hence during the LOI burn I become an ascending Angel. (The first time I did think the moon was getting to look awfully big in the window!)

Not sure at which step I've gone wrong?

Sounds like you didn't have your pericynthion high enough after you did the Trans-lunar course correction. You should check after both TLI and TLCC that your PeA for the fly-by is around 111km. Here's the relevant step from the document (from the TLI secion):

Use the LTMFD flight monitor to check the accuracy of the completed burn. Click [PRG], then select “Flight Monitor”. In the flight monitor screen, click [VM] until the screen shows “Fly-by Moon rel.” and determine that the PeT and PeA values are relatively close to nominal. (A few 10s of km off for PeA and/or a few minutes for PeT can be corrected with the course correction burn during the long TLI coast.)

The course correction burn is necessary to account for orbital perturbations during the long coast. You should follow the same steps you used to perform TLI, and after the burn is complete, your PeA (pericynthion altitude) should be around 111km. The course correction should be late enough in the flight that the pericynthion won't change too much before LOI.

 

[Odahs]

Sounds like you didn't have your pericynthion high enough after you did the Trans-lunar course correction. You should check after both TLI and TLCC that your PeA for the fly-by is around 111km. Here's the relevant step from the document (from the TLI secion):


The course correction burn is necessary to account for orbital perturbations during the long coast. You should follow the same steps you used to perform TLI, and after the burn is complete, your PeA (pericynthion altitude) should be around 111km. The course correction should be late enough in the flight that the pericynthion won't change too much before LOI.

Thanks Shifty, got it saved just after the TLI burn so will check through the figures. I went through it again and got the same calculations from LTMFD and the same result of a fly-by exactly intersecting the moon surface. I'll run through again from my save point taking care to follow the step you posted very carefully.

---------- Post added at 05:43 PM ---------- Previous post was at 05:20 PM ----------

Gone back to my save point, I get PeT 75:54:22 PeA 55 K ish but steadily dropping? Forwarding through time the PeA value continues to fall towards zero and then is not corrected by the TLCC burn.

Do I assume from this the TLI burn failed and I need to go back to before it?

I do hope my questions are helpful for the guide and not just to me!

 

[Shifty]

Gone back to my save point, I get PeT 75:54:22 PeA 55 K ish but steadily dropping? Forwarding through time the PeA value continues to fall towards zero and then is not corrected by the TLCC burn.

Do I assume from this the TLI burn failed and I need to go back to before it?

I do hope my questions are helpful for the guide and not just to me!

Yeah, thanks for the feedback! If you could quicksave after your TLI burn, then copy and paste that scenario that scenario file inside code tags here, I'll take a look at it when I get home. It's actually normal for the PeA to drop while coasting after the TLI burn, but the TLCC should correct it. Are you verifying that PeA is set to 111 km before you calculate the TLCC burn?

For the TLCC burn:

1. Set PeT to 75:20:50
2. Set PeA to 111 km
3. Set TIg to 26:44:58
4. Click [EXE] to calculate the burn
5. Click [DV] to go to the thrust monitor
6. Click [EXE] to turn on the auto-burn autopilot.

 

[Odahs]

I'm thinking I may have missed setting the TIg time (leaving the time set by LTMFD) but otherwise I followed each step. Definitely setting PeA to 111km before the TLCC burn each time. The TLCC burn seems very short at 0.28 seconds.

Docking for LM Extraction
END_DESC

BEGIN_ENVIRONMENT
  System AMSO\Sol
  Date MJD 40418.7028092014
END_ENVIRONMENT

BEGIN_FOCUS
  Ship AS-506
END_FOCUS

BEGIN_CAMERA
  TARGET AS-506
  MODE Cockpit
  FOV 47.26
END_CAMERA

BEGIN_HUD
  TYPE Surface
END_HUD

BEGIN_VC
END_VC

BEGIN_SHIPS
AS-506:AMSO\Apollo
  STATUS Orbiting Earth
  RPOS -2591552.57 1729949.90 14257451.35
  RVEL -5793.275 469.856 4399.443
  AROT -173.70 -0.26 43.97
  AFCMODE 7
  PRPLEVEL 0:0.999964
  NAVFREQ 0 1 2 3
  XPDR 0
  STATE 9
  LANDINGSITE 0
  ABORTSTATUS 0
  ABO1TYP 0
  MJDLOI 40421.723495
  MJDLDG 40422.846528
  MJDSPL 40426.701794
  SPLLON -172.400000
  SPLLAT 10.600000
  MISSIONTIME 11986.340409
  PWR 0.000000
  BEACON 0
END
AS-506_Stage3:AMSO\Saturn_STG3
  STATUS Orbiting Earth
  RPOS -2591553.39 1729948.81 14257415.96
  RVEL -5793.279 469.850 4399.242
  AROT 1.81 -1.23 -108.27
  AFCMODE 7
  PRPLEVEL 0:0.050000
  NAVFREQ 0 1 2 3
  XPDR 0
  STATE 1
END
AS-506_Stage3_conepart1:AMSO\Saturn_STG3C1
  STATUS Orbiting Earth
  RPOS -2591619.93 1729817.65 14257331.58
  RVEL -5793.935 468.557 4398.296
  AROT -112.02 25.53 -179.37
  VROT 8.16 1.49 -0.97
  AFCMODE 7
  PRPLEVEL 0:1.000000
  NAVFREQ 0 0
END
AS-506_Stage3_conepart2:AMSO\Saturn_STG3C2
  STATUS Orbiting Earth
  RPOS -2591683.64 1730010.62 14257326.87
  RVEL -5794.562 470.455 4398.250
  AROT 124.12 57.69 15.00
  VROT 8.05 -1.80 0.99
  AFCMODE 7
  PRPLEVEL 0:1.000000
  NAVFREQ 0 0
END
AS-506_Stage3_conepart3:AMSO\Saturn_STG3C3
  STATUS Orbiting Earth
  RPOS -2591490.66 1730074.18 14257320.69
  RVEL -5792.664 471.079 4398.189
  AROT 120.57 -20.87 -175.48
  VROT -7.97 -2.44 -1.00
  AFCMODE 7
  PRPLEVEL 0:1.000000
  NAVFREQ 0 0
END
AS-506_Stage3_conepart4:AMSO\Saturn_STG3C4
  STATUS Orbiting Earth
  RPOS -2591426.94 1729881.21 14257325.40
  RVEL -5792.038 469.182 4398.235
  AROT -131.28 -55.53 39.41
  VROT -8.29 -0.13 0.97
  AFCMODE 7
  PRPLEVEL 0:1.000000
  NAVFREQ 0 0
END
END_SHIPS

---------- Post added at 07:08 PM ---------- Previous post was at 06:44 PM ----------

Just loaded the scenario above and checked the figures, they seemed OK until after I dock with the LM. It is only after extraction of the LM that the PeT figure starts to drop down fairly rapidly.

Starting figures

PeT 75:53:01 PeA steady at 104.64 K

Then after docking PeA is seen to drop steadily.

This is my after docking scenario:

BEGIN_DESC
LM+CSM ejected - off to the moon!
END_DESC

BEGIN_ENVIRONMENT
  System AMSO\Sol
  Date MJD 40418.7073985136
END_ENVIRONMENT

BEGIN_FOCUS
  Ship AS-506
END_FOCUS

BEGIN_CAMERA
  TARGET AS-506
  MODE Extern
  POS 2.27 -61.88 -2.58
  TRACKMODE TargetRelative
  FOV 47.26
END_CAMERA

BEGIN_HUD
  TYPE Surface
END_HUD

BEGIN_VC
END_VC

BEGIN_SHIPS
AS-506:AMSO\Apollo
  STATUS Orbiting Earth
  RPOS -4859627.02 1900538.20 15871738.93
  RVEL -5641.348 394.499 3774.325
  AROT 179.32 2.21 53.76
  RCSMODE 2
  AFCMODE 7
  PRPLEVEL 0:1.000000
  DOCKINFO 0:0,AS-506_LM_vessel
  NAVFREQ 0 1 2 3
  XPDR 0
  STATE 10
  LANDINGSITE 0
  ABORTSTATUS 0
  ABO1TYP 0
  MJDLOI 40421.723495
  MJDLDG 40422.846528
  MJDSPL 40426.701794
  SPLLON -172.400000
  SPLLAT 10.600000
  MISSIONTIME 12382.856987
  PWR 0.000000
  DLMS 0
  SPCEVA 0
  GOTK1 0
  GOTK2 0
  SPCDTH 0
  LMPDTH 0
  OPENSM 0
  SUBSAT 0
  MAGANT 0
  PASBRK 0
  LMCRBK 0
  BEACON 0
END
AS-506_Stage3:AMSO\Saturn_STG3
  STATUS Orbiting Earth
  RPOS -4859628.15 1900538.15 15871703.89
  RVEL -5641.355 394.499 3774.125
  AROT -0.68 -2.21 -108.76
  AFCMODE 7
  PRPLEVEL 0:0.050000
  NAVFREQ 0 1 2 3
  STATE 3
  EVTT 102.241638
END
AS-506_Stage3_conepart1:AMSO\Saturn_STG3C1
  STATUS Orbiting Earth
  RPOS -4859952.42 1899898.46 15871265.45
  RVEL -5641.995 393.232 3773.339
  AROT -164.27 7.65 141.01
  VROT 8.11 -1.74 -0.96
  AFCMODE 7
  PRPLEVEL 0:1.000000
  NAVFREQ 0 0
END
AS-506_Stage3_conepart2:AMSO\Saturn_STG3C2
  STATUS Orbiting Earth
  RPOS -4860263.94 1900840.48 15871244.42
  RVEL -5642.618 395.108 3773.305
  AROT 161.18 33.50 58.30
  VROT 8.24 0.36 1.03
  AFCMODE 7
  PRPLEVEL 0:1.000000
  NAVFREQ 0 0
END
AS-506_Stage3_conepart3:AMSO\Saturn_STG3C3
  STATUS Orbiting Earth
  RPOS -4859321.56 1901149.94 15871211.79
  RVEL -5640.738 395.723 3773.229
  AROT -173.97 4.15 159.67
  VROT -8.30 -0.69 -1.07
  AFCMODE 7
  PRPLEVEL 0:1.000000
  NAVFREQ 0 0
END
AS-506_Stage3_conepart4:AMSO\Saturn_STG3C4
  STATUS Orbiting Earth
  RPOS -4859010.42 1900208.31 15871232.82
  RVEL -5640.117 393.847 3773.263
  AROT -170.15 -13.70 88.73
  VROT -7.51 -3.52 0.77
  AFCMODE 7
  PRPLEVEL 0:1.000000
  NAVFREQ 0 0
END
AS-506_LM_vessel:AMSO\LM_vessel
  STATUS Orbiting Earth
  RPOS -4859627.26 1900538.28 15871731.34
  RVEL -5641.348 394.499 3774.325
  AROT 95.78 -71.11 173.17
  AFCMODE 7
  PRPLEVEL 0:1.000000
  DOCKINFO 0:0,AS-506
  NAVFREQ 0 1 2 3
  XPDR 0
  STATE 1
  C1DEAD 0
  C2DEAD 0
END
END_SHIPS

 

[Shifty]

Just loaded the scenario above and checked the figures, they seemed OK until after I dock with the LM. It is only after extraction of the LM that the PeT figure starts to drop down fairly rapidly.

I'll check your scenarios in a couple hours, when I'm home, but it almost sounds like you have an autopilot or engine running. After docking, can you hit numpad-* to make sure engines are all off, and also make sure that all your autopilots (killrot, prograde, etc) are off?

 

[dgatsoulis]

Could be a perturbation problem. I can't say for LTMFD but for IMFD the Map program works more accurately with nonspherical gravity switched on.

-Shifty, when you wrote the tutorial, did you have nonspherical gravity switched on or off?

-Odahs, do you have the same perturbation setting as Shifty's tutorial?

 

[Shifty]

Could be a perturbation problem. I can't say for LTMFD but for IMFD the Map program works more accurately with nonspherical gravity switched on.

-Shifty, when you wrote the tutorial, did you have nonspherical gravity switched on or off?

I believe it was on. I should probably include that setting in the tutorial notes.

 

[dgatsoulis]

My guess is that Odahs is flying with nonspherical gravity switched off and that's what's causing the discrepency.

 

[Shifty]

My guess is that Odahs is flying with nonspherical gravity switched off and that's what's causing the discrepency.

I can confirm. I tried with perturbations off and got his results; then on and got different, more stable ones. I'll edit the guide to include this and re-upload later this evening.

---------- Post added 07-29-14 at 01:21 AM ---------- Previous post was 07-28-14 at 11:15 PM ----------

OK, I updated the document with the information about non-spherical gravity. I also included a reference to clive bradbury's tutorial and cleaned up a few typos and ambiguities.

 

[Odahs]

Gone back to my save point before the TLI burn and checked nonspherical gravity to on.

All is fine after the burn, then as soon as I separate the CSM and rotate it for docking the PeA value is seen to drop by around 50K and continue dropping steadily.

I'll start again from the beginning but it's all a bit perplexing!

 

[Shifty]

Gone back to my save point before the TLI burn and checked nonspherical gravity to on.

All is fine after the burn, then as soon as I separate the CSM and rotate it for docking the PeA value is seen to drop by around 50K and continue dropping steadily.

I'll start again from the beginning but it's all a bit perplexing!

You shouldn't need to start over. The translation you do for docking will change your PeA quite a bit. (Note that as you said the TLCC is something like 0.28 seconds, which is enough to move the PeA from 26 km to 111 km.) I used the "after docking" scenario you provided then did the TLCC at ~GET 26 hours, and afterward, PeA was 111 km and stable all the way to the moon.

 

[Odahs]

Strange, ran through doing the same thing and after TLCC PeA was not stable and I crashed and burned again! I'll run through it again from the save point.

---------- Post added at 06:52 PM ---------- Previous post was at 12:45 PM ----------

Been through a few times again. After the TLI I'm now fairly stable at around PeA 50 K. But keep ending up with a PeA around 400 - 500 K after the TLCC burn, which degrades to minus values by the time I get to the moon. I'm sure I'm entering 111.1 K each time as the desired PeA value.

I can only figure now that it is something I'm not doing right whilst setting up the TLCC burn.

Is it possible Shifty to post up the setting you are using before calculating the TLCC burn?

As I can only assume the tripping point for me is the line 'Repeat the steps carried out to perform TLI' - and that I'm missing something that needs to be checked/set for the TLCC burn.

 

[Shifty]

Is it possible Shifty to post up the setting you are using before calculating the TLCC burn?

As I can only assume the tripping point for me is the line 'Repeat the steps carried out to perform TLI' - and that I'm missing something that needs to be checked/set for the TLCC burn.

Yeah, I'll upload my scenario with the MFD's all set up for you this evening. This is a strange problem I'd like to get to the bottom of.

---------- Post added at 11:46 PM ---------- Previous post was at 08:21 PM ----------

OK, I made a set of four quicksaves for you (attached to this post):
1) The 'after docking' scenario you posted with LTMFD in the left MFD set up to calculate the burn. Click EXE, then DV, then EXE to turn on the autoburn. The right MFD is set up with the LTMFD flight monitor.
2) Right before TLCC. (You have to calculate and execute the burn again. Quicksave doesn't save these states.)
3) Right after the TLCC with PeA set to 111km, which you can see in the Flight Monitor on the right MFD
4) About an hour before LOI, with PeA still at 111km.

I also made this video with my totally non-existent video skills, which you are free to mock

Set Up for TLCC

 

[Odahs]

Thanks Shifty.

Running from 02-Just Before TLCC I get to the moon OK with a stable trajectory - I'll need to work back through some of my saves and see if I can replicate my previous problem.

I think possibly the Line 'Repeat the steps carried out to perform TLI' had me setting "Mod" to Surface and "Tgt" to Tranquility Base as I had for the TLI burn, which isn't required for the TLCC?

I then got to an hour before LOI, put in the numbers and EXE get 'no solution'.

Loaded up your 04-Hour Before LOI and get the same result.

I've attached the scenario

 

[Shifty]

Thanks Shifty.

Running from 02-Just Before TLCC I get to the moon OK with a stable trajectory - I'll need to work back through some of my saves and see if I can replicate my previous problem.

I think possibly the Line 'Repeat the steps carried out to perform TLI' had me setting "Mod" to Surface and "Tgt" to Tranquility Base as I had for the TLI burn, which isn't required for the TLCC?

I then got to an hour before LOI, put in the numbers and EXE get 'no solution'.

Loaded up your 04-Hour Before LOI and get the same result.

I've attached the scenario

Once you're that close the the moon, LTMFD likely won't give you a solution for course correction. At that point you should be asking it to calculate the LOI burn.

And, I really should have done the course correction with Tranquility Base on surface mode selected (to ensure that the orbital inclination of the insertion orbit is correct.) Glad that the orbit stayed stable for you though. I wonder what the issue was.