Question AMSO

[richfororbit]

Hi,

So I've downloaded this AMSO addon, it was made sometime ago and has the whole collection of missions to the moon.

I tried the mission 13 one, I had the damage on, and then an alarm goes off over two days later into the mission. Ofcouse I tried the steps to see the different time positions.

As for the free return trajectory, just how was the Lunar Module used, when I loaded the step the front hatch was facing the Earth, as if the craft would of gone to the moon vertically to the surface.

I wasn't clear on the mission pack.

Scenario step 7
---------------

Here we simulate the first trajectory correction made with the
full stack, with the LM vessel. It consisted to return the
CSM+LM stack to the free return trajectory.

IMFD is ready for this burn, so you just need to activate the
auto-burn feature.


Scenario step 8
---------------

Nothing special in this scenario. It is just the dramatic
time when Apollo 13 passed the PeA point on the back side of
the Moon, without any communications with Earth.


Scenario step 9
---------------

Here we will simulate the historical long burn made with the
LM, to accelerate the return to Earth and obtain a better
landing point which the carrier USS Iwo Jima could reach
before the reentry of Apollo 13.

This correction require the usage of our autopilot fictitious
program P13. This program allow to orient the LM vessel to
a reference position, without the need to take in account the
thrusting axis translation. In other words, we can orient the
LM vessel like it would be the CSM. We can then specify the
delta-V we want for the burn.

The program will translate the thrust axis with an initial 90
degrees rotation, to put the LM hovering engine on the required
thrust axis and perform the burn to obtain the desired delta-V,
while keeping stable all the stack during the burn. The burn
will occur exactly 180 seconds after the P13 is engaged.

In this scenario, the LM vessel is already optimally oriented.
Don't ask me why it is oriented this way. This would lead us
to deep considerations about space navigation , which are out
of the scope of this tutorial. Maybe, in future AMSO version
this fictitious P13 program will have the capacity to make
this burn fully automatically. So you won't have to orient
the vessels stack manually and estimate the Delta-V.

Press "K" key. Now press "Down" arrow key, to switch to "10"
increment mode. With "left/right" arrow key, set 244 M/S for
the burn delta-V (Historical delta-V was 261.5 M/S). Now, wait
until the clock arrive to 2:38 UT and press "Up" arrow key.
The LM will translate to proper thrust axis and start the burn
exactly 180 seconds later.

During the burn, you can watch the evolution of the orbital
parameters on the right IMFD.


Scenario step 10
----------------

This is the simulation of the famous "hand made" midcourse
correction, where astronauts burned LM main engine, while
keeping LM aligned with the Earth horizon.

Scenario make this correction later than the reality, again
because of the need to be into Earth sphere of influence, to
have valid datas on our instruments.

All is set for the correction. Fire the main LM engine
cautiously with the "0/ins" key on the numeric pad, until
PeA on left IMFD instrument reach 43.500 km. Be very precise
with this correction, if you want to get a precise splashdown
location. If you miss, you can switch the RCS to linear and
fine tune with up/down RCS command.

That is what the following is. How ever to essentially get it right through the prior steps is the challenging part, the timeing of when to do certain tasks.

I also just gave this a read.

Fifteen hours before the explosion occured, Apollo 13 made a mid course correction that put the spacecraft on a lunar landing course. Now that Apollo 13 wasn't going to land on the Moon, a return-to-Earth trajectory had to be achieved, but the lunar module navigation system was not designed for this situation. Mission Control figured out a 35 second burn fired five hours after the explosion and a five minute burn done later was conducted to speed up the return home. The Sunwas used as an alignment star to allow the navigation system in the lunar module know where it was pointing at any one time.

According to this page. http://apollo13page.tripod.com/story.html

 

[RonDVouz]

In the actual mission the explosion took place after the crew made a mid course correction, they were on a free return trajectory until they made the correction and had to get back on that course using the LM descent module engine. Also, Interplanetary MFD is a bit too complicated to be using for a lunar transfer, the same guys make a LunarTransfer MFD (on the same download page as IMFD). I suggest trying that.

And I'll be honest, I've done nearly every mission in AMSO except A-13. I've used this NASA site as a flightplan for my sims and as long as I launch on time the actions in the sim line up pretty well with the timeline. Unfortunately A-13 does not have a timeline, but there are plenty of websites that have a chronological order to the events of that mission.

http://history.nasa.gov/SP-4029/Apollo_08i_Timeline.htm

You can simply change the mission number in the URL to access the timeline of any mission, except 13.

 

[boogabooga]

Also, Interplanetary MFD is a bit too complicated to be using for a lunar transfer...And I'll be honest, I've done nearly every mission in AMSO except A-13.

Seems about right.


Actually, setting up the necessary lunar free return trajectory is something IMFD excels at.

I suggest actually learning to use IMFD well, before unleashing your misguided opinions on new Orbitnauts.

 

[RonDVouz]

Speaking of misguided, what tells you I haven't learned IMFD?

 

[Cras]

LTMFD is good at doing Apollo like transfers to the moon and back. IMFD is good for doing everything, you can easily use IMFD to set up you flight, and AMSO even has a feature that will stick in the proper TIGs into IMFD as well.

With that being said, RonDVouz is right, LTMFD is the way to go, it pretty much sets it up all for you, and if you have the time line, you just pump in the numbers, you can even pump in the orbit altitudes if you like, and you will be spot on.

One thing to realize with LTMFD, you will not need the mid course corrections that the real Apollo flights did. LTMFD is so accurate you will pretty much hit your target with no correction whatsoever. You might need to do a couple second burst with your RCS but that will be it.

 

[richfororbit]

There are steps of the mission as you'd know. So if I do the engine burn for thirty five seconds which is a midcourse correction then go around the moon or well the back side of the moon.

Then this needs to be done using the IMFD, but there is only transfere, trans x available.

Scenario step 9
---------------

Here we will simulate the historical long burn made with the
LM, to accelerate the return to Earth and obtain a better
landing point which the carrier USS Iwo Jima could reach
before the reentry of Apollo 13.

This correction require the usage of our autopilot fictitious
program P13. This program allow to orient the LM vessel to
a reference position, without the need to take in account the
thrusting axis translation. In other words, we can orient the
LM vessel like it would be the CSM. We can then specify the
delta-V we want for the burn.

The program will translate the thrust axis with an initial 90
degrees rotation, to put the LM hovering engine on the required
thrust axis and perform the burn to obtain the desired delta-V,
while keeping stable all the stack during the burn. The burn
will occur exactly 180 seconds after the P13 is engaged.

In this scenario, the LM vessel is already optimally oriented.
Don't ask me why it is oriented this way. This would lead us
to deep considerations about space navigation , which are out
of the scope of this tutorial. Maybe, in future AMSO version
this fictitious P13 program will have the capacity to make
this burn fully automatically. So you won't have to orient
the vessels stack manually and estimate the Delta-V.

Press "K" key. Now press "Down" arrow key, to switch to "10"
increment mode. With "left/right" arrow key, set 244 M/S for
the burn delta-V (Historical delta-V was 261.5 M/S). Now, wait
until the clock arrive to 2:38 UT and press "Up" arrow key.
The LM will translate to proper thrust axis and start the burn
exactly 180 seconds later.

During the burn, you can watch the evolution of the orbital
parameters on the right IMFD.

I tried to install the lunar one, where is it?

 

[Cras]

IMFD and LTMFD and Basesync are all on Jarmonik's web page, they are not on the hangar.

 

[richfororbit]

Okay I turned the module on in the setting. I have gone through the Lunar MFD I can't quite see a p13 program.

 

[N_Molson]

It is said in AMSO manual you quoted that "P13" is a 'fictious' (as the 13 suggests) program, and also that you have to do quite a lot (well...) of things manually :

Press "K" key. Now press "Down" arrow key, to switch to "10"
increment mode. With "left/right" arrow key, set 244 M/S for
the burn delta-V (Historical delta-V was 261.5 M/S). Now, wait
until the clock arrive to 2:38 UT and press "Up" arrow key.
The LM will translate to proper thrust axis and start the burn
exactly 180 seconds later.

Moreover, it says that you can use the (non-AMSO specific) MFD's to monitor the progress of the burn. There is no "P13" there, the idea is to use the "map" view to check the trajectory and your orbital parameters.

 

[richfororbit]

Why did they state a program named 13 if isn't there?

---------- Post added at 09:33 PM ---------- Previous post was at 09:32 PM ----------

Why did they state a program named 13 if isn't there?

Well in the scenario after the incident, I've now powered up the Lunar Module. So it is another four hours until the first engine burn for thirty five seconds, then around the moon, and then arrives the complicated tasks.:uhh:

 

[Cras]

As it was once said...."we choose to go to the moon...not because it is easy, but because it is hard."

 

[NukeET]

Also, Interplanetary MFD is a bit too complicated to be using for a lunar transfer

Really? I used IMFD on ALL of my Apollo scenario packs (8,12,14,15,16). That's how I got really good with it. I use LTMFD when I'm lazy or in a hurry.

 

[richfororbit]

As it was once said...."we choose to go to the moon...not because it is easy, but because it is hard."

I guess when it arrives to do step 9, the only way to do so is to just rotate the stack. But that alone isn't going to get the task done correctly.