Project Orion MPCV

[boogabooga]

And is there any plan for an autopilot (for lazy people like me )?

There is a parallel development of a multistage2015 SLS launcher that had some compatibility for this:
http://www.orbiter-forum.com/showthread.php?t=37569&highlight=Space+Launch+System

Multistage has built-in autopilot.

IMHO, the multistage should become standard.

 

[gattispilot]

SLS 2016 Uses Multistage and has an EUS.

 

[francisdrake]

Is it possible to have a typical launch profile with some values for Alt + inclination during launch?

I noted the flight parameters during a typical launch with the EUS. The values are rounded off, but give a general idea of the flight profile. 3/4 fuel are left in the EUS after SECO.

Time Alt Inc TAS Vspd Remarks
[km] [°] [m/s] [m/s]
30 1 90 100 100 Start pitchover
85 15 60 500 470
110 30 40 900 700
120 40 25 1100 730 Booster sep, hold inclination
245 108 30 1900 300 Fairing sep
440 150 20 4800 200 Start pitchup
490 170 30 6000 500 Meco; pitch down to 10°
950 270 10 7000 0 Ascent ends; keep Vspd ± 0
1030 270 0 7325 0 Seco, orbit 270 x 270 km, 83 k fuel.

 

[pclaurent]

Orange-SLS autopilot

... And finally a - quite basic - autopilot for Orange-SLS in its default EUS configuration. Azimuth can be configured between 40 and 140°. The AP stops when EUS+Orion reach a parking orbit between 250 and 300 km (due east, a little less when az diverges to north or south).
To install: copy slsap.lua in the Script directory, launch Orbiter, run the Lua console window and execute run('slsap').

 

[francisdrake]

Absolutely great! Thank you very much Philippe.

Without any experience on Lua skript, I started the EMS-2 scenario, opended the Lua console window and typed run('slsap') and go() as described. It worked beautifully. I think, this was the first time that I could watch the SLS launch relaxed in outboard view.

The autopilot is very stable. 10x time acceleration without problems. The launch is fuel efficient, the remaining fuel in the EUS was more than with any of my manual launches. Great job!

 

[pclaurent]

I'm glad that you like it (I just discovered LUA in this occasion...). Perhaps I will improve it a bit, not so happy with the azimuth control... And I think it wouldn't be a big deal to integrate the script in your development (there is somewhere an API entry to call an LUA script, so you could assign a key to the AP).

 

[pclaurent]

For those interested in the previous version, here is an upgraded autopilot for FrancisDrake's Orange-SLS. Have fun...

 

[Interceptor]

For those interested in the previous version, here is an upgraded autopilot for FrancisDrake's Orange-SLS. Have fun...

Hi is this autopilot for orbiter 2010,or 2016?Thanks

 

[pclaurent]

Hi is this autopilot for orbiter 2010,or 2016?Thanks

It is for Orbiter 2016, and works with Francisdrake's "Orange-SLS"

 

[Interceptor]

It is for Orbiter 2016, and works with Francisdrake's "Orange-SLS"

OK,thank you for making this.

 

[francisdrake]

... here is an upgraded autopilot for FrancisDrake's Orange-SLS.

I tried it and it works very well! The autopilot now has a very realistic roll-to-heading.

Even tried it with the smaller ICPS (which it is not built for) and it was still very usefull in the first phase of the launch to achive correct heading. The first stage needs then to be cut off manually, because it is overpowered for this kind of mission.

All in all, the autopilot is a very helpfull tool to give a good start to the Orion missions.

 

[pclaurent]

Here is a new MFD including 2 autopilots for Orion-MPCV: SLS-launch and Orion reentry. It replaces the slsap.lua script. Please read the documentation for installation instructions. Any feedback welcome...
Phil

 

[francisdrake]

Thank you, Phil, for adding this great tool to the Orion-MPCV!
Today I had a chance to test the AP MFD.

The MFD is easy to handle. The fuctions of the MFD are self explaining. Both scripts worked. The reentry AP sent me into a ballistic reentry, maybe I had already overshot the rentry window.

In the first two status lines (MET and next line) after the text gibberish characters appeared. This looks like a not-terminated string passed on to the MFD.

Question: Would it be possible, that the launch AP is not so strict in checking the initial heading while on the ground? For convenience of the non-AP users I have the SLS oriented 220° in the EM1, so it has only to pull back (without rolling) to achived an ISS type orbit. The AP detects this (mis-)alignment and refuses to start in this case.

 

[pclaurent]

Here is an updated OrionAP.cfg with new heading limits (now 200 to 340°). Just replace the existing one in Config\MFD.

The file includes other enhancements. In the RNT mode, you can somehow control your reentry path if you unlock the Retrograde mode and gently roll the ship to the right for going up, and to the left for going down, until you exactly follow the circles. It can be a funny experience to improve your targeting skills... But note that the initial reentry orbit must exactly match the desired splashdown point. No lateral correction is possible.

I didn't reproduce the "funny characters" problem. Possibly an out-of-limit formating. If you get it again, just send me the info like launch azimuth and MET when you get the faulty display.

 

[pclaurent]

File attached...

 

[francisdrake]

Thanks for the update! I could start the EM-1 scenario to the ISS with the initial heading without problems.

On the reentry: The default orientation would actually be a 'heads down' attitude with occasional rolls to left and right, but unfortunately there is no autopilot for 'downright' in Orbiter. Not a big thing, just to shut off the retrograde autopilot.

On the funny characters:
I made a screenshot below. They appear regardless of any mode or step, even when still on the ground. They are starting to the right of the information strings.

 

[pclaurent]

Very strange… Using DXD9 client I tested various MFD refresh rates (1x and 10x par sec) as well as several MFD sizes and never noticed that. Anyway, here is a patch that should solve the problem.

For the reentry process, I’ve chosen to use the Retrograde mode to accelerate the descent and have a more or less predictable descent rate, which is fine for an autopilot… If I use the “head down” mode, the capsule somehow skips on atmosphere, which is normal and perfect for high speed reentry (e.g. return from the moon) as it limits the number of Gs, but more difficult to control from a pure automation point of view. At least it was my opinion, but not so sure now… The result is a not so accurate reentry autopilot, and I would be happy to get some good advices for implementing a better one. The key questions for designing such a tool are:

How to estimate the braking burn point (distance to target or long/lat)?
How to control the descent rate for a more accurate landing point?
And, ideally, how to control the lateral course and maintain the direction to target?​

I spent a good amount of hours testing various empirical solutions for all this stuff, but I reached my limits, as I’m not – at all – an aerospace engineer. So all suggestions are welcome…

 

[francisdrake]

The new AP dll works fine! No more strange characters.
It is absolutely great to watch the SLS launch in external view, no need to manually adjust pitch and yaw to reach orbit.

On the reetry autopilot: I see this an added bonus and am happy with it. It allows a more precise landing than any manual retro-burn.

 

[IgorCruZ]

I really liked this project, the exhaust effects of the engines are very realistic, I was able to complete the orbit with the fuel of the first stage, leaving the second stage still complete ... I found this strange, but did not disturb nothing,... good work!

 

[CommanderJackShmidt]

Hello, I just downloaded MPCV for Orbiter 2016, I made sure I got the right version, but I'm getting:
000000.000: >>> ERROR: No vessel class configuration file found for:
============================ ERROR: ===========================
Orion-MPCV\Orion-MPCV
[Vessel::OpenConfigFile | .\Vessel.cpp | 243]
===============================================================
000000.000: >>> TERMINATING <<<