Shuttle FDO MFD

[GLS]

Are you using nonspherical gravity? I can't recommend that yet with the MFD. The procedure is to delete the first maneuver from the constraints table after it was executed. The first maneuver in the table needs a time as the threshold, so what you can do is copy the TIG from the evaluation table for e.g. the NC-1 maneuver and use that as the new threshold for it, instead of M=2.0. The same procedure applies to NC-2, but in that case the maneuver was a placeholder, targeted as 8.0 ft/s fixed. So when NC-1 is done you should change the maneuver type of NC-2 to a phasing burn (NC), so that it can correct any errors in phasing that happened so far. In the process of the mission you will eventually have most maneuvers at a fixed TIG.

Yeah, I think I failed in all of the above, as after MC-4 I'm almost 500Km away from the ISS :facepalm:, although it was close enough to be seen about 2 or 3 orbits ago. Anyway, not (super) bad for my first run... :shifty:
Very good MFD!

 

[indy91]

Yeah, I think I failed in all of the above, as after MC-4 I'm almost 500Km away from the ISS :facepalm:, although it was close enough to be seen about 2 or 3 orbits ago. Anyway, not (super) bad for my first run... :shifty:
Very good MFD!

Yeah, it's definitely not easy to use, but it's closely modeled on what the actual Shuttle FDOs used, so, it's their fault, not mine, haha. And here I thought they would improve the user friendliness of the calculation tools since Apollo, but I guess not. When more issues of the MFD are fixed it should be a quite powerful tool for all kinds of rendezvous planning.

And you will definitely have to recalculate the plan after each maneuver. Even with near perfect execution there will be small difference that propagate to something significant over such a long period of time. Especially critical is the NH type maneuver on rendezvous day, you'll phase far away from the ISS again if the TIG is off by just a few seconds of what it should be.

The best instruction manual is the FDO Console Handbook that you can get if you have a L2 subscription on NASA Spaceflight. I really wish it was public, there are detailed instructions on how to calculate each type of maneuver and so much other stuff. Once the next update is ready I'll probably give a walkthrough of a whole rendezvous with each step I have done, and not just for the initial planning before OMS-2.

EDIT: Released another version of the MFD: https://github.com/indy91/Shuttle-FDO-MFD/releases/tag/0.1.2-alpha The changes are, roughly:

-Better iteration behavior
-Nonspherical gravity is better supported now, but probably still not as good as it should be
-Saving/loading of rendezvous plans
-Improved spacing between maneuvers on the maneuver evaluation table
-STS-114 and STS-126 files with rendezvous profile loaded
-Various fixes

I have attached the STS-114 scenario I talked about a few days ago. It's basically the STS-114 Post OMS-2 scenario that comes with SSU, except that it got an updated ISS state vector from Two-Line Elements. Shuttle SV is as it was. With that and nonspherical gravity enabled the predicted necessary plane change is below 10 ft/s. I'll test fly STS-114 if that actually is the case. So scenario wise the two scenarios I have posted so far are for testing of the nonspherical gravity logic diabled (STS-126) and enabled (STS-114).

 

[indy91]

Ah, problem with the STS-114 Post OMS-2 scenario. The clock in that scenario has started at the time when the prelaunch scenario started, it seems, not at liftoff. So it's 10 minutes ahead of what the mission time should be. Had an interesting effect though. I did NC-1 10 minutes too early, which only has a small effect on the next few maneuvers, but it rotated the line of apsides in an undesirable way, so that the TI DVZ component became 32 ft/s.

EDIT: Fixed the scenario above by decreasing the MET by 10 minutes.

 

[GLS]

Ah, problem with the STS-114 Post OMS-2 scenario. The clock in that scenario has started at the time when the prelaunch scenario started, it seems, not at liftoff. So it's 10 minutes ahead of what the mission time should be.

The MET clock is started at SRB ignition, so that is most likely the result of editing the scenario...

---------- Post added at 07:25 PM ---------- Previous post was at 07:21 PM ----------

A small sidestep for the External MFD load/save: the scenarios have this block at the end:

BEGIN_ExtMFD
END

Is this for External MFDs? Does this even work? (I don't remember ever seeing anything in there)

 

[indy91]

A small sidestep for the External MFD load/save: the scenarios have this block at the end:

BEGIN_ExtMFD
END

Is this for External MFDs? Does this even work? (I don't remember ever seeing anything in there)

Oh, I hadn't noticed that. Maybe it saves the MFD data there instead of the normal place, at the beginning of a scenario. I have completely removed the normal MFD saving/loading, but I will certainly test now if it puts anything in that section.

 

[Gingin]

Thanks for the work Indy.
Can’t wait to try complex rendez vous mission with multiple satellite RV like early style STS mission

 

[Wolf]

Downloaded the latest alpha. I see that the STS-114 starts from post OMS-2.
In case I wanted to use a pre OMS-2 scenario which will end up with a different orbit compared to the “default scenario” you have used what exactly needs to be done? is it fine to edit the mission text file by adding OMS-2 data and by doing so will the subsequent burns data change accordingly after my OMS-2 burn?

 

[indy91]

Thanks for the work Indy.
Can’t wait to try complex rendez vous mission with multiple satellite RV like early style STS mission

That would be really fun. When I am done with testing STS-114 I'll probably take a look at one of these earlier missions. The History of Space Shuttle Rendezvous has a whole chapter about STS-39, which is very complex for both ground targeted and onboard targeted rendezvous maneuvers.

Downloaded the latest alpha. I see that the STS-114 starts from post OMS-2.
In case I wanted to use a pre OMS-2 scenario which will end up with a different orbit compared to the “default scenario” you have used what exactly needs to be done? is it fine to edit the mission text file by adding OMS-2 data and by doing so will the subsequent burns data change accordingly after my OMS-2 burn?

You don't need to edit the text file, you can do that in the MFD. That's what the "insert maneuver" option on the constraints page is for, the INS button. Just add the same things as in the STS-126 case:

press INS, type: "1 HA OMS-2" (inserts maneuver in the first positon, maneuver type is height adjustment, name of burn is OMS-2).

Then give it a threshold by pressing THR: "1 T 0:0:30:0" (1 means first maneuver in the table, T is the threshold type time, and the time is 0:30h MET. That will make the OMS-2 burn not-earlier-than 0:30h MET.)

And the maneuver needs two secondary constraints, so press SEC and type "1 APO 1" to make the maneuver occur at the first apoapsis after the threshold time. And then press SEC again and type "1 HD 85" to make the desired height of the height adjustment maneuver 85NM.

And the NC-1 maneuver, which is now the 2nd maneuver in the plan, should then be given the TIG-less threshold, which is 3 orbits after OMS-2. That is STS-114 specific. So type "2 M 3" to make the 2nd maneuver in the table happen 3 orbits (M = 3) after the previous one. And as the last step you probably should delete the constraint, that the NC-1 maneuver happens at apogee. For that press the DES button (delete secondary) and type: "2 1", to delete the 1st secondary constraint of the 2nd maneuver in the table.

This is a quite typical operation with the MFD. When you are all done with this, I would save the plan under some other name, so that it doesn't overwrite the default one. I am currently flying STS-114 to test how it works with nonspherical gravity so I have simply called the work-in-progress plan "STS-114A", but it can be anything you want.

 

[Wolf]

Thanks a lot Indy! This MFD may not be the most intuitive one to use but I guess once you master it then t’s great fun

One more question: Is there a way to retain the pages loaded when changing view in VC (not using external MFDs) with SSU?

 

[Gingin]

@Indy91: I was exactly thinking to that mission .
I read that book and since I always wanted to try those kind of rendez vous.

I love the 2 d plot of the relative motion between target and chaser,its like art.

First thing I will test with your mfd will be sts 400 and sts 135 to get a hand on the mfd.
Then multiple rendez vous

Just need to renew my nasa forum L2 to get a hand to FDO volume 3

 

[indy91]

Thanks a lot Indy! This MFD may not be the most intuitive one to use but I guess once you master it then t’s great fun

Yeah, it's closely modelled on what the Shuttle FDOs had to use and add to that the clumsy input methods of an MFD as compared to a proper computer program. And also add me not being all that great when it comes to user friendliness of my MFDs. :lol:

One more question: Is there a way to retain the pages loaded when changing view in VC (not using external MFDs) with SSU?

You mean that it retains the specific page that was open? Yeah definitely possible, I'll implement that. Just always used the external MFD so far so I didn't really notice. I guess that issue is the same thing as the external MFDs have when you resize the MFD window.

I love the 2 d plot of the relative motion between target and chaser,its like art.

Totally agree.

First thing I will test with your mfd will be sts 400 and sts 135 to get a hand on the mfd.
Then multiple rendez vous

Sounds challenging, haha. Just setting up the right rendezvous profile will be tricky, it's a bit of trial and error and looking at the maneuver times, if it was an actually flown mission.

 

[GLS]

That would be really fun. When I am done with testing STS-114 I'll probably take a look at one of these earlier missions. The History of Space Shuttle Rendezvous has a whole chapter about STS-39, which is very complex for both ground targeted and onboard targeted rendezvous maneuvers.

Another pdf gathering dust on my to-read-from-start-to-end-list... :facepalm:
Anyway, I knew I'd read something somewhere about phase angles, and it was there:

The phase window was based on a 185 nm average ISS orbital altitude and an 85 nm minimum perigee limit for the orbiter. The phase angle at OMS-2 can vary from 37 degrees to 311 degrees for a Flight Day 3 rendezvous and 211 degrees to 505 degrees for a Flight Day 4 rendezvous.

 

[Wolf]

You mean that it retains the specific page that was open? Yeah definitely possible, I'll implement that. Just always used the external MFD so far so I didn't really notice. I guess that issue is the same thing as the external MFDs have when you resize the MFD

Yes that s exactly the issue

 

[indy91]

Yes that s exactly the issue

How do you even use the Shuttle screens for the MFD? I am able to display any MFDs on them, but you can't see the 12 MFD buttons and there are only 6 buttons below the screen, so how do you use all of them? Even if it is possible to use all functions of the MFD this way, this makes it even much less user friendly than it is when using the external MFD.

Another pdf gathering dust on my to-read-from-start-to-end-list... :facepalm:
Anyway, I knew I'd read something somewhere about phase angles, and it was there:

The specific rendezvous profile will depend on that phase angle. In the case of really small phase angles the OMS-2 maneuver already becomes a phasing maneuver with a perigee that can be much higher than 85NM. Because such a large range of phase angles can be supported there have to be different profiles and not just one profile with differing altitudes in between maneuvers. The profiles that were used in the last few years of Shuttle operations are all quite similar, but when setting up the MFD for a new mission you will still need to look at it on a mission per mission basis.

 

[Wolf]

How do you even use the Shuttle screens for the MFD? I am able to display any MFDs on them, but you can't see the 12 MFD buttons and there are only 6 buttons below the screen, so how do you use all of them? Even if it is possible to use all functions of the MFD this way, this makes it even much less user friendly than it is when using the external MFD.

Yes it is quite messy. You have to play with the buttons available (pressing the first one on the right swaps between changing pages or just variables in the same page). What I do is opening one MFD (usually the Maneuver evaluation table) in the SSU screen and the other in external MFD mode.
I don’t know about you guys but if I open 2 external MFDs my FPS dramatically drop (even below 10FPS) and Orbiter becomes unplayable. I cannot imagine what would happen when using ISS AtoZ in the scenario...
Are you still getting decent FPS with both screens opened in external MFD mode?

 

[indy91]

I don’t know about you guys but if I open 2 external MFDs my FPS dramatically drop (even below 10FPS) and Orbiter becomes unplayable. I cannot imagine what would happen when using ISS AtoZ in the scenario...
Are you still getting decent FPS with both screens opened in external MFD mode?

Oh, I don't have that issue at all. External MFDs aren't doing anything bad my framerate. I wonder if I am doing anything wrong in the code of the MFD to cause that. Do you get the same issue if you have one or more of the stock Orbiter MFDs open in the External MFD?

 

[Snax]

I had the same issue with opening some ExtMFD killing my FPS, the more ExtMFD I open, the more FPS I loose.
Now for some magical reason it's over.
I onoy had it on my desktop, nothing on my laptop.

Had the same with ExtMFD and DX9 ExtMFD

 

[indy91]

I had the same issue with opening some ExtMFD killing my FPS, the more ExtMFD I open, the more FPS I loose.
Now for some magical reason it's over.
I onoy had it on my desktop, nothing on my laptop.

Had the same with ExtMFD and DX9 ExtMFD

Hmm, weird. But I guess that means it is nothing specific about the FDO MFD!? Just the ExtMFD having some issues maybe. And if the plan from the SSU guys is to eventually set up a MCC vessel in Orbiter where you can do the mission planning then you can use the normal MFDs, so that shouldn't be an issue. I'll definitely change the FDO MFD so that you aren't forced to use it from the Shuttle, but can access it anywhere.

---------- Post added at 09:28 ---------- Previous post was at 09:16 ----------

Yesterday evening I finished a STS-114 rendezvous with nonspherical gravity enabled. And it worked really well (minus the bugs in the MFD I fixed along the way)! As I said before the state vectors of the Shuttle and ISS should be pretty realistic in my starting scenario. In terms of plane change I had to do a 9 ft/s NPC burn and then later the NCC and TI burns both had about 1 ft/s out-of-plane components to null the remaining out-of-plane error. But that was it with any plane changes, the Shuttle nicely drifted into the orbital plane of the ISS due to the differential nodal regression. The lighting might have been off by 1-2 minutes, but I am not quite sure about that. I have to check when the sunset after TI really happened. It felt like the sun was setting and rising too late as compared to what the rendezvous checklist says. It might be some deficiency with dealing with the nonspherical gravity.

Onboard targeting worked good enough. The preliminary TI burn solution had a weird 8 ft/s DVY component, but that might be caused by the nonspherical gravity not taken into account for the trajectory propagation to the time of TI. The later solutions were close enough to my ground calculated one that I burned the onboard solution. The MCs were definitely larger than without nonspherical gravity, but still only 1-2 ft/s each. I tried the radar mode of the Ku Band antenna for the first time, it did a nice and successful search for the target and the R and Rdot display is definitely useful in the later part of the rendezvous.

 

[Wolf]

Hmm, weird. But I guess that means it is nothing specific about the FDO MFD!? Just the ExtMFD having some issues maybe. And if the plan from the SSU guys is to eventually set up a MCC vessel in Orbiter where you can do the mission planning then you can use the normal MFDs, so that shouldn't be an issue. I'll definitely change the FDO MFD so that you aren't forced to use it from the Shuttle, but can access it anywhere.

No that happens with any MFD; interesting to know that I am the only one suffering a huge FPS drop by doing this

Yesterday evening I finished a STS-114 rendezvous with nonspherical gravity enabled. And it worked really well (minus the bugs in the MFD I fixed along the way)! As I said before the state vectors of the Shuttle and ISS should be pretty realistic in my starting scenario. In terms of plane change I had to do a 9 ft/s NPC burn and then later the NCC and TI burns both had about 1 ft/s out-of-plane components to null the remaining out-of-plane error. But that was it with any plane changes, the Shuttle nicely drifted into the orbital plane of the ISS due to the differential nodal regression. The lighting might have been off by 1-2 minutes, but I am not quite sure about that. I have to check when the sunset after TI really happened. It felt like the sun was setting and rising too late as compared to what the rendezvous checklist says. It might be some deficiency with dealing with the nonspherical gravity.

Onboard targeting worked good enough. The preliminary TI burn solution had a weird 8 ft/s DVY component, but that might be caused by the nonspherical gravity not taken into account for the trajectory propagation to the time of TI. The later solutions were close enough to my ground calculated one that I burned the onboard solution. The MCs were definitely larger than without nonspherical gravity, but still only 1-2 ft/s each. I tried the radar mode of the Ku Band antenna for the first time, it did a nice and successful search for the target and the R and Rdot display is definitely useful in the later part of the rendezvous.

Great news :thumbup:

 

[indy91]

Published another release: https://github.com/indy91/Shuttle-FDO-MFD/releases/tag/0.1.3-alpha

A bunch of bug fixes and you will now be able to use the MFD from anywhere and are not constraint to using it in the active vessel.

Also, here the Maneuver Constraints Tables from my STS-114 mission.

Before NC-1:

Before NC-2:

Before NPC:

Before NH:

Before NC-4:

Before TI:

A few notes on how I changed the table after each maneuver. First you need to delete the first burn in the table, because that was just executed and doesn't matter anymore. The new first maneuver in the table needs a fixed time input, at least as the threshold. So for NC-2 I took the TIG from the evaluation table and input it as a new T constraint. The NC-2 was a fixed, placeholder burn of 50 ft/s before NC-1, but after NC-1 it becomes the new phasing burn that corrects any errors. Ended up being exactly 50 ft/s anyway.

For the NPC maneuver I initially use a DT of 1 second after the previous burn, just to make it search for the common node (CN) with the target after NC-2. When NPC is the first maneuver in the table then a TIG input is needed, which was just a random time a few minutes after NC-2. The actual TIG will still happen at the common node due to the CN secondary constraint. Also, the "DR = -40" constraint needs to be removed from NC-4, because there is no phasing maneuver anymore to iterate on that.

For NH the TIG is the fixed number that has been used throughout the mission. I fixed that TIG very early on because it achieves the specific lighting I wanted. Oh and I checked the lighting in my STS-114 scenarios, it was exactly on time, so my feeling that it was off I posted about above was wrong. After the NPC burn the WEDG constraint needs to be removed from TI, because there is no more pure plane change burn.

After NH I used the TIGs for the NC-4 and TI maneuvers from the evaluation table and kep them fixed throughout the rest of the rendezvous. The DH constraint needs to be removed, because there is no more NH type maneuver.

Same thing after NC-4, the "DR = -8" constraint needs to be removed, because there is no more NC maneuver.