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Apollo 13 LM upper stage.



 
 
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  #11  
Old March 1st 11, 02:07 PM posted to sci.space.history
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Posts: 1,516
Default Apollo 13 LM upper stage.

On Mar 1, 6:31*am, Pat Flannery wrote:
On 2/28/2011 12:47 PM, Ken S. Tucker wrote:

It was challenging enough to have the LM thrust the CSM load,
something it was never designed for, or spec'd for, but Grumman
put enough balls into the upper-LM stage to do it!


It also had to sustain heavy loads on the docking collar then the CSM
braked itself and the LM into lunar orbit.

Pat


my point was that if the upper LM had been detached at the same time
the still attached LM was there was likely enough fuel to put the LM
upper stage in earth orbit or heliospheric.

I didnt say it was a good idea.....

imagine though a museum display.

here we have the apollo 11 LM upper stage, its lower half is still on
the moon undisturbed/

Over here we have the apollo 13 LM upper stage from the flight with
the explosion

over here is the hubble space telescope, at its end of use nasa
boosted it into a high stable orbit, it was recently retrieved by
shutte 2.

here we have snoopy, and a saturn booster that was lost in
heliospheric orbit for over 80 years.

sad most of this is impossible
  #12  
Old March 1st 11, 02:28 PM posted to sci.space.history
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Default Apollo 13 LM upper stage.

On Mar 1, 8:07*am, " wrote:
On Mar 1, 6:31*am, Pat Flannery wrote:

On 2/28/2011 12:47 PM, Ken S. Tucker wrote:


It was challenging enough to have the LM thrust the CSM load,
something it was never designed for, or spec'd for, but Grumman
put enough balls into the upper-LM stage to do it!


It also had to sustain heavy loads on the docking collar then the CSM
braked itself and the LM into lunar orbit.


Pat


my point was that if the upper LM had been detached at the same time
the still attached LM was there was likely enough fuel to put the LM
upper stage in earth orbit or heliospheric.

I didnt say it was a good idea.....

imagine though a museum display.

here we have the apollo 11 LM upper stage, its lower half is still on
the moon undisturbed/

Over here we have the apollo 13 LM upper stage from the flight with
the explosion

over here is the hubble space telescope, at its end of use nasa
boosted it into a high stable orbit, it was recently retrieved by
shutte 2.

here we have snoopy, and a saturn booster that was lost in
heliospheric orbit for over 80 years.

sad most of this is impossible


after the LM was jettisoned could the ground seperated the upper stage
and commanded a burn of its upper stage to send it heliospheric?

this wouldnt of added any work onboard

just wondering.............
  #13  
Old March 1st 11, 02:57 PM posted to sci.space.history
Jeff Findley
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Posts: 5,012
Default Apollo 13 LM upper stage.

In article abc05e9c-8ff5-4f7b-868f-dfb157565028
@o18g2000prh.googlegroups.com, says...

On Mar 1, 6:31*am, Pat Flannery wrote:
On 2/28/2011 12:47 PM, Ken S. Tucker wrote:

It was challenging enough to have the LM thrust the CSM load,
something it was never designed for, or spec'd for, but Grumman
put enough balls into the upper-LM stage to do it!


It also had to sustain heavy loads on the docking collar then the CSM
braked itself and the LM into lunar orbit.

Pat


my point was that if the upper LM had been detached at the same time
the still attached LM was there was likely enough fuel to put the LM
upper stage in earth orbit or heliospheric.


Even if there was enough fuel, I doubt there was enough time. Apollo 13
had to keep the LEM attached until the "last possible moment" since the
CSM had only (reentry) battery power left in the CM (the SM was "dead"
because it contained fuel cells which had no LOX to run them).
http://history.nasa.gov/SP-4029/Apollo_13h_Timeline.htm

From above:

Event GET(hhh:mm:ss) GMT Time GMT Date
LM jettisoned. 141:30:00.2 16:43:00 17 Apr 1970
Entry. 142:40:45.7 17:53:45 17 Apr 1970

Power was the consumable which was in the shortest supply on Apollo 13's
return trip. That's why the LEM got so cold on the return trip(no spare
power to run any heaters).

Jeff
--
" Solids are a branch of fireworks, not rocketry. :-) :-) ", Henry
Spencer 1/28/2011
  #14  
Old March 2nd 11, 03:31 AM posted to sci.space.history
Ken S. Tucker
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Posts: 740
Default Apollo 13 LM upper stage.

On Mar 1, 3:31 am, Pat Flannery wrote:
On 2/28/2011 12:47 PM, Ken S. Tucker wrote:

It was challenging enough to have the LM thrust the CSM load,
something it was never designed for, or spec'd for, but Grumman
put enough balls into the upper-LM stage to do it!


It also had to sustain heavy loads on the docking collar then the CSM
braked itself and the LM into lunar orbit.
Pat


"heavy loads", Not really, 1 inch / sec is an easy closing speed.
(I can sim a soft landing on the moon doing that, so can automated
landings).
The LEM was between the descent stage engine and the CSM and
the descent engine had a minimum thrust, obviously within specs.
Ken


  #15  
Old March 2nd 11, 05:54 PM posted to sci.space.history
Pat Flannery
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Posts: 18,465
Default Apollo 13 LM upper stage.

On 3/1/2011 6:31 PM, Ken S. Tucker wrote:
On Mar 1, 3:31 am, Pat wrote:
On 2/28/2011 12:47 PM, Ken S. Tucker wrote:

It was challenging enough to have the LM thrust the CSM load,
something it was never designed for, or spec'd for, but Grumman
put enough balls into the upper-LM stage to do it!


It also had to sustain heavy loads on the docking collar then the CSM
braked itself and the LM into lunar orbit.
Pat


"heavy loads", Not really, 1 inch / sec is an easy closing speed.
(I can sim a soft landing on the moon doing that, so can automated
landings).


No, when the CSM with the LM attached to its nose entered lunar orbit,
it used the big service module engine to do it.
The service module engine produced 21,900 lbs. thrust.
This would be pushing on the heavy fully-fueled LM's docking collar.
When they fired up the LM descent engine on Apollo 13 its total thrust
when running full-out was only 10,125 lbs. and they may not have run it
at full thrust either.
Push on it from the CSM side or from the LM side and the total stress on
the docking collar assembly remains the same.

Pat
  #16  
Old March 2nd 11, 09:02 PM posted to sci.space.history
Ken S. Tucker
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Posts: 740
Default Apollo 13 LM upper stage.

On Mar 2, 8:54 am, Pat Flannery wrote:
On 3/1/2011 6:31 PM, Ken S. Tucker wrote:

On Mar 1, 3:31 am, Pat wrote:
On 2/28/2011 12:47 PM, Ken S. Tucker wrote:


It was challenging enough to have the LM thrust the CSM load,
something it was never designed for, or spec'd for, but Grumman
put enough balls into the upper-LM stage to do it!


It also had to sustain heavy loads on the docking collar then the CSM
braked itself and the LM into lunar orbit.
Pat


"heavy loads", Not really, 1 inch / sec is an easy closing speed.
(I can sim a soft landing on the moon doing that, so can automated
landings).


No, when the CSM with the LM attached to its nose entered lunar orbit,
it used the big service module engine to do it.
The service module engine produced 21,900 lbs. thrust.
This would be pushing on the heavy fully-fueled LM's docking collar.
When they fired up the LM descent engine on Apollo 13 its total thrust
when running full-out was only 10,125 lbs. and they may not have run it
at full thrust either.
Push on it from the CSM side or from the LM side and the total stress on
the docking collar assembly remains the same.
Pat


Not quite sure your thesis holds Pat, cuz the CSM is quite a bit
heavier
than the Descent Stage, so the force = mass x acceleration would need
to be all figured out.
Ken
  #17  
Old March 2nd 11, 09:34 PM posted to sci.space.history
Jeff Findley
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Posts: 5,012
Default Apollo 13 LM upper stage.

In article a5dbee9b-47ce-483b-ae12-4e88cd16def1
@o30g2000pra.googlegroups.com, says...

On Mar 2, 8:54 am, Pat Flannery wrote:
On 3/1/2011 6:31 PM, Ken S. Tucker wrote:

On Mar 1, 3:31 am, Pat wrote:
On 2/28/2011 12:47 PM, Ken S. Tucker wrote:


It was challenging enough to have the LM thrust the CSM load,
something it was never designed for, or spec'd for, but Grumman
put enough balls into the upper-LM stage to do it!


It also had to sustain heavy loads on the docking collar then the CSM
braked itself and the LM into lunar orbit.
Pat


"heavy loads", Not really, 1 inch / sec is an easy closing speed.
(I can sim a soft landing on the moon doing that, so can automated
landings).


No, when the CSM with the LM attached to its nose entered lunar orbit,
it used the big service module engine to do it.
The service module engine produced 21,900 lbs. thrust.
This would be pushing on the heavy fully-fueled LM's docking collar.
When they fired up the LM descent engine on Apollo 13 its total thrust
when running full-out was only 10,125 lbs. and they may not have run it
at full thrust either.
Push on it from the CSM side or from the LM side and the total stress on
the docking collar assembly remains the same.
Pat


Not quite sure your thesis holds Pat, cuz the CSM is quite a bit
heavier
than the Descent Stage, so the force = mass x acceleration would need
to be all figured out.


True. A quick web search suggests that the fully loaded CSM mass was
nearly twice that of the fully loaded LM. So, the force on the LM side
of the docking interface would have been something around 7300 lbs
during the burn of the SM's engine. The actual value would go up as the
burn progressed due to the mass of fuel/oxidizer expended by the SM's
engine.

I'm not sure about the force caused by the LM's engine on the docking
interface during Apollo 13 because to figure that out, you'd need to
know the mass of the CSM and LM at the time of the burn. I'm sure
someone at NASA figured that out (close enough) to do the burn, but that
still would have been an estimate given the damage to the SM.

Jeff
--
" Solids are a branch of fireworks, not rocketry. :-) :-) ", Henry
Spencer 1/28/2011
  #18  
Old March 3rd 11, 09:41 AM posted to sci.space.history
Pat Flannery
external usenet poster
 
Posts: 18,465
Default Apollo 13 LM upper stage.

On 3/2/2011 12:02 PM, Ken S. Tucker wrote:

No, when the CSM with the LM attached to its nose entered lunar orbit,
it used the big service module engine to do it.
The service module engine produced 21,900 lbs. thrust.
This would be pushing on the heavy fully-fueled LM's docking collar.
When they fired up the LM descent engine on Apollo 13 its total thrust
when running full-out was only 10,125 lbs. and they may not have run it
at full thrust either.
Push on it from the CSM side or from the LM side and the total stress on
the docking collar assembly remains the same.
Pat


Not quite sure your thesis holds Pat, cuz the CSM is quite a bit
heavier
than the Descent Stage, so the force = mass x acceleration would need
to be all figured out.


CSM weighed 66,871 pounds; LM weighed 32,399 pounds. (Wikipedia)
Since CSM weighs around twice as much as LM, but SM engine generates
twice as much thrust as LM descent engine, stress on the docking collar
would be nearly identical in both situations.
And that assumes LM engine was run at full thrust.
Does anyone know if that was the case in Apollo 13?
They would get a lot better velocity control at LM engine shutdown if
they ran it longer at lower thrust.

Pat
  #19  
Old March 3rd 11, 01:42 PM posted to sci.space.history
[email protected]
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Posts: 1,516
Default Apollo 13 LM upper stage.

On Mar 3, 3:41*am, Pat Flannery wrote:
On 3/2/2011 12:02 PM, Ken S. Tucker wrote:







No, when the CSM with the LM attached to its nose entered lunar orbit,
it used the big service module engine to do it.
The service module engine produced 21,900 lbs. thrust.
This would be pushing on the heavy fully-fueled LM's docking collar.
When they fired up the LM descent engine on Apollo 13 its total thrust
when running full-out was only 10,125 lbs. and they may not have run it
at full thrust either.
Push on it from the CSM side or from the LM side and the total stress on
the docking collar assembly remains the same.
Pat


Not quite sure your thesis holds Pat, cuz the CSM is quite a bit
heavier
than the Descent Stage, so the force = mass x acceleration would need
to be all figured out.


CSM weighed 66,871 pounds; LM weighed 32,399 pounds. (Wikipedia)
Since CSM weighs around twice as much as LM, but SM engine generates
twice as much thrust as LM descent engine, stress on the docking collar
would be nearly identical in both situations.
And that assumes LM engine was run at full thrust.
Does anyone know if that was the case in Apollo 13?
They would get a lot better velocity control at LM engine shutdown if
they ran it longer at lower thrust.

Pat- Hide quoted text -

- Show quoted text -


vaguely i think course correction burns were pretty long which would
indicate not full throttle...
  #20  
Old March 3rd 11, 04:23 PM posted to sci.space.history
Brian Thorn[_2_]
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Posts: 2,266
Default Apollo 13 LM upper stage.

On Thu, 03 Mar 2011 00:41:23 -0800, Pat Flannery
wrote:

And that assumes LM engine was run at full thrust.
Does anyone know if that was the case in Apollo 13?


Remember, Aquarius fired its DPS engine three times: Free Return (MET
61:29:43), PC+2 (MET 79:27:39) and Course Correction (MET 105:18:28).

According to Lovell's _Lost Moon_, the Free Return burn started at low
throttle and then went up to 40%.

The PC+2 burn was 5 seconds at minimum thrust, then 21 seconds at 40%
thrust, and finally 4 minutes at full thrust. Lovell handled the
throttle, the computer handled the timing.

The Course Correction burn was at low throttle (10%).

Brian
 




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