Project Orion MPCV

[DaveS]

NTRS document outlining the Exploration Upper Stage (formerly the Dual Use Upper Stage): http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20130013953.pdf.
In summary: The EUS would be used for the TLI and LOI burns and use its own RCS for a controlled crash on the lunar surface, freeing up the Orion MPS for the TEI burn.

 

[Kyle]

NASA just released a very nice 3D model of SLS. Might work well as a reference!

 

[Astro SG Wise]

Here are some recent pictures with MPCV.

 

[4throck]

Looks great. Very happy to see the current version of Orion in Orbiter.

From my tests on the old Constellation version, the EDS+Orion+Altair TLI / LOI is indeed tricky and a bit beyond my piloting. Perhaps the TLI is done over multiple perigee burns?
When I do a sing burn with the EDS, it feels too long and I move too much along the orbit...

 

[francisdrake]

4throck, with your excellent Constellation addon you raised the quality level to new heights!

In Orbiter it is tricky to do stack burns properly (like Orion + Altair + upper stage) . I tend to end up in skewed lunar orbits with too much fuel spent.

The current Orion is lacking a published mission archtecture, or a mission beyond a circumlunar flight. My best guess is NASA will develop a solar electric propulsion stage, and Orion will meet it at an Earth-Moon Lagrange point. I have been hunting the Lagrange points recently with Orion + SLS upper stage, which is a challenge on its own!

 

[Astro SG Wise]

Yeah, I am going to try that Constellation Addon out some time. Looks great! In the meanwhile, some more Orion pics. (I've been busy.)

I am always wondering what form the NASA Mars stack will take. I have been fiddling around with Mars Design Reference missions, and creating my own Phobos exploration devices.

 

[4throck]

4throck, with your excellent Constellation addon you raised the quality level to new heights!

In Orbiter it is tricky to do stack burns properly (like Orion + Altair + upper stage) . I tend to end up in skewed lunar orbits with too much fuel spent.

The current Orion is lacking a published mission archtecture, or a mission beyond a circumlunar flight. My best guess is NASA will develop a solar electric propulsion stage, and Orion will meet it at an Earth-Moon Lagrange point. I have been hunting the Lagrange points recently with Orion + SLS upper stage, which is a challenge on its own!

Thanks!
Well, Velcro and UCGO/UMMU help. They make the add-ons come alive.
The downside is indeed stack handling. But my copy/paste code skills can't handle a proper .dll implementation.

On my plans I have an asteroid / Lagrange points mission but indeed the info is lacking.
I'll look into the old Apollo Applications proposals to see if I find something of use...

 

[dave1705]

Hi, I noticed something, that buged me. The docking petals aren't in the correct alignment. I don't know, if you want to go into such details.
Here is, what it should be:

But anyway, keep up with the good work! :thumbup:

 

[spacman]

Orion

Also just FYI Orion is the active docker it will not have docking alignment cross . It will be plain white material. Thank you for work in making this model come to life :thumbup:

 

[francisdrake]

Thanks for pointing me to the docking detail. I did not notice that previously. Will update the mesh. Just to clarify: If Dave's picture shows the passive part (with the cross), would the petals on the Orion be mirror inverted, to fit in between, right?

 

[DaveS]

Thanks for pointing me to the docking detail. I did not notice that previously. Will update the mesh. Just to clarify: If Dave's picture shows the passive part (with the cross), would the petals on the Orion be mirror inverted, to fit in between, right?

Yes. More information can be found in the official IDSS (International Docking System Standard) document: http://www.internationaldockingstandard.com/download/IDSSIDD-DCN-001_Revision_C.pdf

 

[dave1705]

Thanks for pointing me to the docking detail. I did not notice that previously. Will update the mesh. Just to clarify: If Dave's picture shows the passive part (with the cross), would the petals on the Orion be mirror inverted, to fit in between, right?

The petals should be the same look as the passive counterpart, if you place them aside and the same direction.

These images could help:

It's the IDA from back view.
You can better see here:

 

[4throck]

Just posting some general info I gathered from several NASA planing docs, and that seems to work on on my Constellation. May be useful here, since some concepts are similar.

Initial earth rendezvous Orbit is 241km.
The EDS stage would perform some burns to get the stack into a 185x1806 orbit for TLI.
LOI is performed by Altair, to an initial 100x10000 orbit. 3 burns will circularize the orbit.

The optimal lunar orbit for PDI and ascent is ~80km.
NASA states 100km but my Altair runs out of fuel trying to reach Orion at that height. At 80km if works ok.

 

[Star Voyager]

I hope I'm posting this in the right place, but I've been trying to use this add-on with LTMFD. When I try to perform a TEI burn, LTMFD says Orion doesn't have enough thrust. Is this Orion underpowered or is there another way to do the TEI?

 

[orbitingpluto]

I hope I'm posting this in the right place, but I've been trying to use this add-on with LTMFD. When I try to perform a TEI burn, LTMFD says Orion doesn't have enough thrust. Is this Orion underpowered or is there another way to do the TEI?

Orion is under powered, at least in comparison to the Apollo CSM that LTMFD expects you to use for TEI. That's less of a mark against the Orion than a legacy of the CSM being built with taking off from the lunar surface in mind, like with the direct mode of operations that was the plan early in Apollo.

A different navigation MFD should work well enough for TEI, though it might not be as easy as LTMFD.:shrug:

 

[Michael_Chr]

I hope I'm posting this in the right place, but I've been trying to use this add-on with LTMFD. When I try to perform a TEI burn, LTMFD says Orion doesn't have enough thrust. Is this Orion underpowered or is there another way to do the TEI?

Noticed that as well. Maybe its because the AUX thrusters (see readme file with OrionMPCV) needs to be activated as well to get enough thrust for a TEI burn. However this AUX thrust cant be calculated in to the burnplanning the way that LTMFD works today. The quick fix I have done is to make a Generic Vessel version of the Orion MPCV where I have used the same Mass(fuel and empty) and ISP but added some thrust for it to work.

 

[francisdrake]

Revived this thread as I made a launcher for it. This is to reduce the dependency on other addons. It is an orange-tank SLS with an interim cryogenic propulsion stage. Re-used the upper stage of my old Delta4Heavy addon for this. The launcher is kept simple. The Orion still works with other launchers of your choice.
Download it from the front page of this thread, Orion-MPCV-09.

No autopilot is provided, but lauching is easy: Start the engines and slowly pull back until the nose is about 20° above the horizon. The boosters separate about 120 seconds into the flight. Or use one of autopilot-MFDs from Orbithangar.

The interim upper stage has enough power to provide the trans Lunar injection and the Lunar capture burn. This saves fuel of the Orion to return later from Lunar orbit.

Made also some minor updates on the Orion's mesh and service module textures.

 

[Kyle]

Absolutely fantastic work francisdrake. I'm glad that this project hasn't been mothballed.

 

[pclaurent]

New 0.9 version

Hi Francis,

Glad to see that your project is still alive! For many months Orion MPCV is my favorite realistic spaceship in Orbiter.

3 things that you could have a look to, to further enhance your model:

1. When MPCV is still attached to the EUS, one cannot dock any module (like Altair lunar module) to Orion. If I try to, and ignite EUS engine, I can see EUS+MPCV passing thru the docked module…
2. In version 0.9, the MPCV virtual cockpit is in plain gray, the former textured panel disappeared.
3. NASA documents show an EUS with 4 engines, not 1 as in your model.

Thanks again for your great job and keep going…

 

[francisdrake]

1. Docking while still being attached to the upper stage:
Ok, that's new To enable this, a 'ghost' docking port belonging to the upper stage, but at the location of the Orion's dock is necessary. But this leads to an re-docking when the Orion is jettisoned. Will have think about this.

Also, the Orion + upper stage stack can probably only be a passive target, as the upper stage has no translation thrusters, which makes active docking nearly impossible.

I assume that a moon lander would fly by itself to lunar orbit or one of the Lagrange points. Then the Orion would be propelled there by the upper stage, but would separate before docking.

2. Seems I inadvertently changed a material name in the model. Will look into it.

3. The model here is the Interim Cryogenic Propulsion Stage (ICPS), which is a Delta 4 upper stage with only one RL-10 engine. This will be used for the first, unmanned Moon flight. I will keep it for now, maybe making the EUS later.