IMFD 5.1m Question

[dkluempers]

I am still a bit new to Orbiter and have spent several days reinstalling and reading a great deal of documentation. I am attempting to use IMFD 5.1m to do a simple trip to the moon. I have Orbiter 2006-P1/DGIV/IMFD5.1m with a number of other textures and MFD's installed.

From my reading it I have thought I understood how to approach this. I used the DGIV->Earth Scenary->Docked at ISS.

I undock, close the nose cone and deploy the Radiator.

I bring up IFMD in both MFD's and configure IMFD to use MJD and select Shared OP with 0 (The L-MFD).

In the R-MFD I select Course->Tangent Intercept. A course is computed and shows on the MFD.

In the L-MFD I select Orbit Eject. I then move the cursor to the Higher Orbit then change it to Course. The L-MFD then display No data avalable from the Course Program.

From my reading I had thought that this was the proper way to do this. I am sure that I have probably just misread or missed a step somewhere but I am hoping that someone can give me a bit of a push in the right direction and I can continue to learn how to use this incredible program.

Thanks very much,

 

[pattersoncr]

Don't use Orbit Eject to go from Earth to the Moon. You're not ejecting from earth orbit. Just use the course program (I would recommend Target Intercept rather than Tangent). You can also use IMFD Map to fine tune things since it's more accurate than the course program. Don't feel bad, I nearly pulled my hair out figuring out the same thing when I first started using IMFD.

P.S
I just noticed your location. I lived in Salt Lake/Mapunapuna until a year-and-a-half ago.

 

[dkluempers]

Thanks very much Chuck. In fact I was using Target Intercept. I just typed in the wrong term. Let me give that a try.

 

[pattersoncr]

Things get really interesting with IMFD when you start to figure out offset targeting to set up free-return trajectories and the like. It's a really powerfull tool.

 

[dkluempers]

I noticed that if I use that scenario and just setup the Target Intercept then hit AB it will acually head my back through the Earth in attempt to do the intercept. I assume I need to get a feel for where I am in orbit and where everthing else is then begin the AB when I am in a better postion.

Once I get the Earth to Moon Orbit done I will try the free-return trajectory. I downloaded the tutorial on it and will give it a read.

With the new addons it is giving Orbiter a whole new dimension. I am really having a good time learning about all of this. Even when I burn up it is actually fun and I learn something.

Thanks again.

 

[pattersoncr]

I noticed that if I use that scenario and just setup the Target Intercept then hit AB it will acually head my back through the Earth in attempt to do the intercept. I assume I need to get a feel for where I am in orbit and where everthing else is then begin the AB when I am in a better postion.

You're on the right track. You need to change your eject time. Adjust Tej (upper left hand corner) until total dV is minimized. Also, make sure "offset" is selected (rather than "realtime"). This will keep IMFD from trying to take a shortcut thru the center of the Earth.

 

[dkluempers]

I tried changing from Realtime to the other mode of Off-Axis (Offset) but IFMD keeps resetting it back to realtime. I am able minimize dv by changing the eject time but for some reason I keep coming out way ahead of the moon. I understand that it would be best to eject when I am in-plane with the moon but in fact this scenario shows I am well out of plane due to the date and were the ISS is. I used the Off Plane to try this and I tried the Target Plane but I must be doing something incorrectly. I will bring up the tutorials again and read through them again. I am betting I missed something.

This is part of the fun though

 

[dkluempers]

I did manage to finally get myself to the moon. The big trick was using the map function of IMFD to determine when I had cleared the earth so that I could do the TLI burn.

I disconnected from the ISS. I setup the RMFD with IMFD for a Course using Target Intercept with Off Plane and Realtime. Setup the LFMD with Map function Ref Earth, Target Ecliptic. That showed me that I was actually headed back around the earth so I needed to wait. As soon as I cleared the earth I did an Auto Burn.

When I entered the Sphere of Influence of the Moon I setup the RMFD using the Course and Planet Appoach. I tried for 150km Pea but unfortunately the approach did not quite work for some reason. I tried another burn but no luck. The Planet Approach program ultimately would no longer work and I assume it was because I was to close.

I could see that my prograde vector was taking me into moon so I did a manual burn back toward the Earth. I then did a manual entry into orbit by turning retrograde and waiting for PeT to time down and did the burn. I was able to change inclination and land at Brighton Beach successfully.

Now I can retry this again tonight to see if i can fine tune this and learn some more. Thanks again for the help.

 

[dkluempers]

One final post on this. I had a real Homer Simpson moment "Dohhhhh!" last night as I tried to figure out why my Planet Approach did not seem to work properly. Finally after re-reading and experimenting I discovered my problem. I had left the Reference as Earth and Target as Moon. When I changed the Reference to Moon and Target to Ecliptic everything fell into place. Of course I was selecting Orbit Insert as the type of entry. I was able to do both Prograde and Retrograde orbits at the altitude I selected. I also used the Base Approach program rather than the Planet Approach and it worked fine as well. The only strange thing was that I could not Target the Base by name so I entered the coordinates manually. Now on to the suggestion of free-returns.