Orbiter-Forum  

Go Back   Orbiter-Forum > Orbiter Space Flight Simulator > MFD Questions & Help
Register Blogs Orbinauts List Social Groups FAQ Projects Mark Forums Read

MFD Questions & Help Post your questions here for help with the Multi-Function Displays.

Reply
 
Thread Tools
Old 06-29-2008, 02:12 PM   #1
Graham2001
Orbinaut
 
Graham2001's Avatar
Default IMDF 5.1 Free Return Scenario Help Wanted

I've just been testing out the 'Free Return' scenario for IMFD 5 and was wondering if someone could advise me on just what steps I need to take to avoid crashing into the moon. Every time I set up the orbit I end up with a 'close approach' that is beneath the surface of the moon.

Can this be avoided at set up, or do I need to carry out a mid-course correction and if so, what steps should I follow?
Graham2001 is offline   Reply With Quote
Old 06-29-2008, 02:45 PM   #2
Master of Blades
Orbinaut
 
Master of Blades's Avatar
Default

Run the "Planet Approach" program when you are getting close to the Moons SOI?
Master of Blades is offline   Reply With Quote
Old 06-29-2008, 06:50 PM   #3
polaris149Tiberius
Tutorial Publisher
 
polaris149Tiberius's Avatar
Default You can read my tutorial

You can read my tutorial:

"From the Earth to The Moon" an AMSO 1.17 Apollo 11 Full Mission Tutorial Using IMFD 5.1h

Go directly to the section called:

Part 2 - Apollo 11 AS-506 Trans Lunar Insertion (TLI)

It will tell you how to do it and yes you will need 1-2 mid course corrections or a Planet Approach burn to fix your originally calculated TLI. This is because when you calculate out the trajectory, you would normally have the Saturn V stage III attached to your orbiting and landing vehicle. If your using AMSO or NASSP you SHOULD finish the first TLI, then extract your LM from the reminents of the stage III and then re-burn using delta V in IMFD to make corrections for the change in mass.

Your change in mass will effect your original trajectory which was done with alot more mass.

The earlier you do a MCC, the better. Your trajectory calculations are about an hour old when you finish docking and extracting your LEM so a very small but less accurate delta V burn can fix the change in mass.
If after the IMFD delta V burn still puts you out too far or too close to the surface of the moon, you can do a trim burn. Stay pointed at the last point IMFD left you after doing the delta V burn and then select your manuver rockets to translation type and press forward or backward to fix the PeA of the moon to about 80km. (note: you can use the fine burn function in your translation type manuver rockets by pressing CTRL+ Numpad 8 or 2 to even more fine tune your trajectory)


Then when your leaving the earth's SOI, you can do an MCC#1 and if needed a second MCC when your about to enter the moon's SOI. This is what NASA did during its Apollo Program circumlunar flights so you can bet we will have to do it in Orbiter.

Hope this helps Good luck, have fun, and please feel free to read my tutorial. I created it for ppl to be able to experience this flight and I would love it if it helped you.
Cheers
polaris149Tiberius is offline   Reply With Quote
Old 06-30-2008, 12:16 AM   #4
Graham2001
Orbinaut
 
Graham2001's Avatar
Default

Quote:
Originally Posted by polaris149Tiberius View Post
 You can read my tutorial:

"From the Earth to The Moon" an AMSO 1.17 Apollo 11 Full Mission Tutorial Using IMFD 5.1h

Go directly to the section called:

Part 2 - Apollo 11 AS-506 Trans Lunar Insertion (TLI)

It will tell you how to do it and yes you will need 1-2 mid course corrections or a Planet Approach burn to fix your originally calculated TLI. This is because when you calculate out the trajectory, you would normally have the Saturn V stage III attached to your orbiting and landing vehicle. If your using AMSO or NASSP you SHOULD finish the first TLI, then extract your LM from the reminents of the stage III and then re-burn using delta V in IMFD to make corrections for the change in mass.

Your change in mass will effect your original trajectory which was done with alot more mass.
Thanks, I'll look over it and see just what I need to adapt for my flight attempt.
Graham2001 is offline   Reply With Quote
Reply

  Orbiter-Forum > Orbiter Space Flight Simulator > MFD Questions & Help


Thread Tools

Posting Rules
BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
Forum Jump


All times are GMT. The time now is 11:25 PM.

Quick Links Need Help?


About Us | Rules & Guidelines | TOS Policy | Privacy Policy

Orbiter-Forum is hosted at Orbithangar.com
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2019, vBulletin Solutions Inc.
Copyright 2007 - 2017, Orbiter-Forum.com. All rights reserved.