Advanced Question AMSO Tutorial: Calculating for TLI

[Kaito]

Im following this tutorial: http://www.orbiter-forum.com/showthread.php?t=1303&highlight=AMSO+Tutorial

I'm setting up IMFD for the TLI. I'm on Section F, Step 31 and 32. With 31, I wasn't able to get my Tot low at all. Still 31K. In step 32, when I change my Rad, my PeA doesn't go down at ALL.

Is it IMFD or is it me? And how do i fix it?

 

[jarmonik]

Im following this tutorial: http://www.orbiter-forum.com/showthread.php?t=1303&highlight=AMSO+Tutorial

I'm setting up IMFD for the TLI. I'm on Section F, Step 31 and 32. With 31, I wasn't able to get my Tot low at all. Still 31K. In step 32, when I change my Rad, my PeA doesn't go down at ALL.

Is it IMFD or is it me? And how do i fix it?

It's difficult to say anything without having a screen shot from the MFDs. If the total delta velocity is 3.1k then it's OK. but if it really is 31k then there must be something wrong in time of flight (TOF). Either the time of arrival or the time of ignition is incorrect. Note that TOF = TIn - TEj.

Is it Apollo 11 mission that you are trying to fly ?

 

[Kaito]

I'm still having this problem. I dont know why i didn't respond...
Yes, i am flying Apollo 11. I adjust my RAD and Lon and nothing changes. The MFD's are shared, i've done everything correctly up until this point.

Any help would be appreciated

 

[Kaito]

I'm not sure if the pictures will show up, but this is how they go:
The picture Rad8M was taken at the same time of PeA395M was. They are from the same screenshot.
The picture Rad4M was taken at the same time of PeASame.

As you can see, even though i cut the Rad in half, the PeA stayed the same. I'm not sure whats causing this.

Hope it helps

 

[Tommy]

If I remember correctly, when setting up the TLI, IMFD's source should be set to Earth, not AS-506. Set the source to self (in this case, AS-506) during the transfer for making MCC's.

 

[tblaxland]

If I remember correctly, when setting up the TLI, IMFD's source should be set to Earth, not AS-506. Set the source to self (in this case, AS-506) during the transfer for making MCC's.

That is the case for interplanetary flights but when flying to the Moon, you can't set the source to the object the target is orbiting (it is like trying to target Mars, with the Sun as the source).

Kaito, can you post a screenshot of the Course program in the graphic mode (press MOD until you see it) - that might provide some more clues.

 

[Kaito]

ooh, okay, i'll try it. Thank you.
Whats MCC?

 

[Tommy]

Mid Course Correction

 

[Kaito]

Kaito, can you post a screenshot of the Course program in the graphic mode (press MOD until you see it) - that might provide some more clues.

I will tomorrow
So, this SHOULDN'T be happening? Should I reinstall IMFD?

 

[Tommy]

There's a hint about the problem on the Map display, it shows a moon PeT of 223.3, where a value close to 275k is expected.

Perhaps some screenshots of IMFD' course program showing the other data (hit the mode button a couple times) might help, or post the scenario file (use "code" tags) so we can see where the disconnect is.

 

[tblaxland]

Should I reinstall IMFD?

I would be surprised if that would make things any better. It looks like there is something wrong the way the course program is setup but I can't tell what.

 

[jarmonik]

I think this is just a minor user error. There are two possibilities.

1. MFDs are not correctly shared and the Map program is not receiving correct data from the course porgram.

2. You have more than one full orbit to go before TLI and the map program doesn't plot the trajectory far enough, just one full orbit. The PeA you see in the map program just happens to be your closest approach to the moon at a time and should be ignored. That's not the data you are interested.

You can either wait until you are closer to TLI burn or you can open the configuration page of the Map program as shown in a begining of part 2 "Part 2 - Apollo 11 AS-506 Trans Lunar Insertion (TLI)" and set the "Time Limit" to "300k" don't forget the "k" this will tell the Map program to plot (propagate) more trajectory. Also confirm that "One Pe/Ref" is set to "Yes" from the configuration page as well.

After that the real pericynthion will appear but remenber that you may need to press "Sel" button the select the pericynthion like in steps 21. - 23.

If this doesn't help take a screen shot from the course program that shows "TEj" and the graphics.