Project Orion MPCV

[Star Voyager]

This is fantastic! I really love how all your add-ons have evolved as the actual program has evolved. The only thing I noticed was that the ICPS automatically ignites upon separation from the core. I can't wait to see what comes next!

 

[francisdrake]

Yes, the ICPS separation is a crude hack. I will iron that out.

Reason is, I did re-write all the code as my last launcher was year ago, for Orbiter 2006. I wanted to get rid of all obsolete function calls, to prepare for a smooth transition to Orbiter 2016.

 

[francisdrake]

Thanks for your feedback!

Put a new version 10 on the front page. Missing panel texture corrected. Stage separation has now retro-rockets and an 8 sec pause before second stage ignition. Added a docking port on top of stack. This is purely experimental. The upper stage cannot push an Orion+lander into a lunar transfer orbit. Also docking without translational RCS is not possible.

In the Scenarios/Orion-MPCV/eXperimental folder is a scenario with the MAV lander docked to the stack. The MAV-addon is required to run this scenario. The lander is suitable to land on Mars or Moon as well. After undocking, the orbit is set for landing at Brighton Beach, using e.g. the Lola-MFD.

 

[pclaurent]

Well done! The docking to Orion works perfectly well (I also tested the Altair lander with it). If you could replicate this mechanism to your previous EUS (v. 0.8), I can imagine we could do our first complete moon mission from TLI to earth return with a moon landing using you MAV or the Constellation Altair...

 

[pclaurent]

It seems that your ICPS flight dynamics model doesn't account the mass of Orion-MPCV. As a result, the total dV available is more than 9900 m/s (as seen in BurnTime MFD), far above the specifications of the powerful EUS. The theoretical total dV is given by: dV = engine eject speed*ln(initial mass/final mass). As your eject speed is 4530 m/s, this gives approx. 3050 m/s for a fully loaded Orion-MPCV, which is just enough for going to the moon...

 

[francisdrake]

Hm, interesting observation! I am not sure if BurnTime MFD accounts for the mass of an attached vessel. When looking into F4 - Object info, it lists correctly the mass of the ICPS with around 30 ton and the Orion-MPCV with 24.790 ton.

When burning blindly until all fuel is used up, I end up at 15.5 km/s. This seems indeed a little high. To my understanding, the parent vessel should account for the mass of attached child vessels, the same as it does for docked vessels. Maybe I have misinterpreted this. Will have a closer look into the API-reference for this.

 

[DaveS]

To my understanding, the parent vessel should account for the mass of attached child vessels, the same as it does for docked vessels.

It doesn't. By default, an attached child doesn't affect the physics of the parent. This has to be implemented on the parent vessel by the author. So you have to manually create the code that adds the mass of the child to the parent.

 

[francisdrake]

Ahh, thank you for clarifying this!
I was tracking down a bug where the Orion did not update its mass properly after jettisoning the fairing segments and the LAS. This is corrected now, and can be be checked in the object info dialog.

I will implement an oapiGetMass (h_docked_Object) at each vessel mode change and add this mass to the launchers SetEmptyMass().

 

[pclaurent]

... And it sounds like you actually made it for your previous version with 4-engine EUS (used as 3rd stage of SLS-Skylab2 by Gattispilot). This time the propulsion data were just correct and consistent with what we actually get when making the TLI to the moon.

 

[barrygolden]

This could evolve too be one of the best addons. I think it needs the clearance lights and a spot light and or strobe to help track it.

Take a look at domany's Orion VC and 4th rock's Orion VC and you'll see an upgrade would dress this up along with charring during reentry as with the AMSO CM. Be sure to check the placement of the side windows, they seem to far forward to me.

I think the Delta 4/ MPCV to support ISS operations is a good thing to keep available . Speaking too some Orion guys at KSC they said that the CM would be covered with silver tape as with Apollo but it looked like the resource module will fly with the round solar panels when operational

 

[francisdrake]

Ok, I added the attached mass to the launcher. This becomes pretty challenging, as the dV of the second stage is barely sufficient to reach the Moon. So I aim for a high (300 km) parking orbit, to use the first stage as much as possible.

The second stage is more or less spent after the lunar injection burn. Only a slingshot is possible around the moon, as the Orion does not have enough power to slow down into lunar orbit and come back.

Given this, I will probably rather model the Exploration Upper Stage (EUS), which is much more versatile than the ICPS. Also with NASA plans it seems the ICPS will be short lived, being used for the first mission only. Human rating of the ICPS has been halted.
---
Regarding a charred heat shield, that would indeed be a nice feature. Will habe a look into that.

 

[barrygolden]

Again super job with this.

Take a look at some switches inside the VC and the lighting inside, seems to darken or lighten depending on the orientation to the sun.
clearance lights, HGA and a scientific bay like the sim bay on Apollo would be great.

The Orion guys did say that for LEO operations the CM would be white and unlike Apollo the Altair would do the LOI burn

 

[francisdrake]

Thanks for the feedback! I added a new version 11 on the front page. This takes care of the mass of the attached Orion. Currently the mass is added manually, as getting the mass from the attachment gave me random crashes after quitting & restarting a scenario.

Aim for a high parking orbit. After the lunar insertion burn now the second stage has only 10 sec burn time left.

Also made some minor mesh corrections, the SLS core stage was slightly too long, and removed some flickering mesh elements in the virtual cockpit. Other beautifications will come later

 

[barrygolden]

will this new version 11 work with the EFT missions you did ?

 

[francisdrake]

will this new version 11 work with the EFT missions?

Short answer: Yes!

Long answer: I tried it with Tom Harringtons Delta IV Launch Vehicles 3.0,
and it worked. Had to deactivate all other add-ons, otherwise CTD.

Code for including the Orion launch mesh on the Delta IV:

Delta4:delta4/Delta4
  STATUS Landed Earth
  POS -80.5646000 28.5314000
  HEADING 30.00
  AFCMODE 7
  PRPLEVEL 0:1.000000
  NAVFREQ 0 0
  PAYLOAD Orion-MPCV/Orion-MPCV
  MESH Orion-MPCV/orion-lasfair
  Z_OFFSET 1.79
  CONFIG 0.000
  PLDWEIGHT 24500
  Fairing_attached 0
  missiontime 0.000000
END

I suggest to try it yourself and maybe post your scenario file.

 

[barrygolden]

I was able to load a saved 03 version into a new orbiter I have and it works up to the point on solar panel deploy, they do not deploy and there is no VC. I did look in the mesh file for Orion launch and found nothing looking like the code you sent. The last time I tried something like this I lost the whole orbiter so I had to start a new test orbiter. I have a version 10 working on the orbiter I use the most and I won't add stuff off the forum into it. I'm not a computer guy so if it won't unzip into the right folders it better not to mess with it. I did open and drag and drop your MPCV into the test version and then felt ok to do that into the orbiter I use the most but that test version is the one thats crapped out with me trying something else from the forum.
Many developers now are doing addons that seem to be not so user friendly.

As I have said this could be one of the best addons as with AMSO and Shuttle fleet but for me user friendly is the most important thing. If you send your e-mail I'll show you some ideas to make this MPCV a great addon [email protected]

 

[barrygolden]

Just put Orion MPCV into my test version and the new switches and us flag,NASA and ESA decals look great. I have docked with the JWST and been to an Asteroid. I have used parts of the ISS to start a moon base and ready to start a new NASA program.

However unable to get Harringtons Delta 4 to launch with the AP and now the Velcro delta 4 has no fairings and dosen't make it to orbit.

Any ideas ?

 

[Kyle]

You could always make a Multistage2015 vessel for the Delta IV!

 

[barrygolden]

Well thats more than what I know how to do. Over the years some of the people on here have help me to be a little more computer literate but this is over my head. For me user friendly is very important. I know this vehicle will never fly and NASA is dragging its feet to keep their jobs for now . In a year they'll announce a new billion dollar program so they can stretch out more jobs another 10 years. But its nice to see what this thing might have done.

 

[francisdrake]

On the Delta 4: It only works for me, if I deactivate all other addons (only Orion and Delta IV are loaded). The Delta autopilot comes up with 'A' and launches after clicking the launch button. Still, I did not figure out how to achieve a certain inclination, and the second stage seems too weak to lift a fully fueled Orion into orbit.

The difficulty of integrating with other launchers was one of the reasons I made the orange SLS launcher. It is simple, but gets the job done.

For the fate of the real-world Orion I am not so pessimistic. I think it is a pretty good piece of hardware. Cost-sharing with ESA is also a step in the right direction.

For the SLS I am a little more pessimistic. It will require a lot of public funding, and probably fly only once every few years. But I see nothing wrong in having a big, fat launcher ready, once the right missions come around!