Author Topic: I didn't know this....  (Read 215 times)

Offline Obviousman

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I didn't know this....
« on: July 29, 2017, 06:10:07 PM »
I was watching a YouTube video regarding Apollo 1 and the lessons learnt (https://youtu.be/ZxBvAB_ekTQ). The panel included Glynn Lunney and Walt Cunningham.

Two things were mentioned during the panel that I didn't know:

- Some time prior to the Apollo 1 fire, there had been some type of ECS coolant fire (can't remember if it was in a Block 1 capsule or not) however the report was classified.

- During the Apollo 11 re-entry, the jettisoned SM also re-entered near the capsule, posing a possible collision hazard instead of skipping off into space.

I thought I knew a lot about the Apollo programme but goes to show that even 48 years later, I am still learning new facts.
« Last Edit: July 29, 2017, 06:24:27 PM by Obviousman »

Offline bknight

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Re: I didn't know this....
« Reply #1 on: July 30, 2017, 12:39:15 AM »
I didn't know that Apollo 11 had a near collision, but I watched the SM burn up on re entry.  I'll post the video link, if I can find it.
Truth needs no defense.  Nobody can take those footsteps I made on the surface of the moon away from me.
Eugene Cernan

Offline Obviousman

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Re: I didn't know this....
« Reply #2 on: July 30, 2017, 12:52:23 AM »
IIRC, the person did not say that they nearly had a collision but rather the crew reported seeing the SM, meaning it had not 'skipped off' and therefore was a possible collision hazard.

Offline bknight

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Re: I didn't know this....
« Reply #3 on: July 30, 2017, 01:00:36 PM »


Here is the link, disregarding the hoax implications of the title, it appears to me that the film captures both the CM and SM in close proximity and then separation prior to the SM disintegration.

https://www.youtube.com/watch?v=fL8HU3fKWJc&t=3s

ETA:
And from the post mission repot page 287-288 https://www.hq.nasa.gov/alsj/a11/A11_MissionReport.pdf
Quote
Photographic data were obtained of the service module entering the
earth's atmosphere and dis integrating near the command module . Pre flight
predictions indicated the service module should have skipped out of the
earth's atmosphere and entered a highly elliptical orbit .
The crew observed the service module about 5 minutes after separation and indicated
the reaction control thrusters were firing and the module was rotating
about the X plane . ยท
Based on the film , crew observation of the service module , and data
from previous missions , it appears that the service module did not perform
as a stable vehicle following command module /service module separation.
Calculations using Apollo 10 data show that it is possible for the
remaining propellant s to move axially at frequencies approximately equal
to the precessional rate of the service module spin axis about the X body
axis . This effect causes the movement to resonate , and the energy transfer
between the rotating vehicle and the propellants may be sufficient to
cause the service module to go into a flat spin about the Y or Z axis and
become unstable .
« Last Edit: July 30, 2017, 02:21:25 PM by bknight »
Truth needs no defense.  Nobody can take those footsteps I made on the surface of the moon away from me.
Eugene Cernan

Offline Obviousman

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Re: I didn't know this....
« Reply #4 on: July 30, 2017, 05:25:59 PM »
Thanks for that - much appreciated. It didn't look that close ('a miss is as good as a mile...') but I don't know.
« Last Edit: July 30, 2017, 05:34:51 PM by Obviousman »