Manual Entry

[ADT187]

Hi All,

I have just finished flying Apollo 11 from launch to splashdown (with a significant amount of help from members of this board!!). Feels great to have finally done it .... thanks for an excellent simulation.

One thing I do fancy having a go at now is a manually flown entry. Has anyone got any good documents detailing how this would have been done?

PS.. On the EMS, I understand the pointer should show the current direction of the CM's lift vector .. is this correct?

Thanks,

Alex

 

[indy91]

The Roll Stability Indicator (RSI) shows the lift direction of the CM, yes.

Some good documentation:

-Wiki Article: http://nassp.sourceforge.net/wiki/Entry_Monitoring_System
-AOH Volume I: https://history.nasa.gov/afj/aoh/aoh-v1-2-03-scs.pdf Starting on PDF page 52
-AOH Volume II with procedures: https://www.ibiblio.org/apollo/Documents/AOH_A16_VOL2_Part_2.pdf PDF page 174 (SCS Entry)

 

[ADT187]

Thanks

 

[MrFickles]

If entering the atmosphere directly from a lunar trajectory, think of your entry as having 2 phases.

The first phase is to get the spacecraft down to below orbital velocity. Use the red and green lines below to safely navigate this phase.

The second phase is like a normal entry from LEO once the spacecraft is below orbital velocity.

The EMS range counter is your actual range to the target. EMS scroll tells you what speed you should be at a given range, as well as how much g you need. If your EMS range counter reaches a certain range before the scroll, you will overshoot the target, fly lift down (and vice versa). However, do not go below the g onset lines (red lines) as you can still over-g the CM at mach 5-10.

Before diving in and flying a completely manual entry with only the EMS scroll, consider flying manually using the CMC calculated bank angle to get used to the handling characteristics of the CM.

 

[ADT187]

Thanks for that! Very helpful diagram, just what I've been looking for. I'll have a go using the CMC angles as you suggest.

Even in my CMC controlled entry the RSI stays stubbornly pointing up. Have been thinking either this is normal behaviour or I may have set up the EMS incorrectly?

Thanks,

Alex

 

[MrFickles]

Are both EMS roll and .05g switches on panel 1 switched on? I assume you already have your EMS set to ENTRY & normal.

EDIT: The RSI works fine for me on your scenario. The entry was done at 340 yaw though, was the entry REFSMMAT correct?

 

[ADT187]

They weren't originally switched on, but when so the RSI works perfectly! Not sure why I hadn't got them on ....... I know the checklist timeline had got screwed up somewhere during the mission and I've had to call each checklist manually.

Same for the REFSMMAT, am not sure in all honesty. Followed timeline as best I could, but may not have loaded it correctly!