Apollo 13 AMSO

[MrFoo]

Hello again, last night I was attempting the Apollo 13 scenario on AMSO.

Does anyone know the preocdure of how to get back on a free return trajectory just after the cryo tank explosion, using the LEM hover engine?

I have tried using IMFD slingshot programme by setting the reference to the moon, but the DV that the autopilot burns, way over 1000k and the LEM has not got enough fuel.

Anyone ever done it? if so how, I was just curious that’s all, its all part of playing around with the simulator.

 

[the.punk]

You can do it very good with IMFD. There is a tutorial for free return. If you are using version 4.2.1 there isn't this tutorial inculded , but you can do it with v 4.2.1. Download the newest version if you haven't this already.
Then go to IMFD/Doc/InterplanetaryMFD/OffsetProcedure then OffsetTuto.

 

[MrFoo]

Ok punk, ill check that out, thanks man.

 

[Tommy]

With Apollo 13, the TMI should establish a free return trajectory. As I recall, the LEM wasn't needed to get back, it was used to hasten the trip due to concerns about the shortage of O2 and issues with the CO2 scrubbers.

After A13, the Apollo missions used a "modified free return" trajectory, since it had now been proven that the LEM could be used to propel the stack.

 

[tblaxland]

After A13, the Apollo missions used a "modified free return" trajectory, since it had now been proven that the LEM could be used to propel the stack.

No, hybrid trajectories started already with Apollo 12. You will find reference to it here: http://history.nasa.gov/ap12fj/05ptc_back_over_to_lm.htm

 

[Tommy]

Boy, i wish NASA would keep their "facts" consistant. Other NASA docs claim the modified free return didn't start til a14. I've also seen significant discrepancies in mission timelines between one doc and another!

 

[Zatnikitelman]

If you Read Apollo 13 (Lost Moon) then you get the whole shebang! They did a 16fps I believe return to free-return burn then kicked it into high gear at PC+2 to shorten the trip time by 10 hours. Maybe if you plugged 4.8768 total Dv into IMFD then hunted around for a burn direction, you could get a free-return that away.