A Space & astronomy forum. SpaceBanter.com

Go Back   Home » SpaceBanter.com forum » Space Science » Space Shuttle
Site Map Home Authors List Search Today's Posts Mark Forums Read Web Partners

Apollo Question



 
 
Thread Tools Display Modes
  #1  
Old August 25th 12, 01:01 AM posted to sci.space.shuttle
[email protected]
external usenet poster
 
Posts: 82
Default Apollo Question

Been meaning to ask this for a while. While sitting on the pad, the Apollo
command module is white. When you see pictures of it in space, it's silver,
almost chrome looking. Is that white a shroud over the entire command module
that's jettisoned when the escape tower is jettisoned? If so, why? Seems like
it's a lot of extra weight at launch. Just been wondering.
  #2  
Old August 25th 12, 03:28 AM posted to sci.space.shuttle
Greg \(Strider\) Moore
external usenet poster
 
Posts: 790
Default Apollo Question

wrote in message ...

Been meaning to ask this for a while. While sitting on the pad, the Apollo
command module is white. When you see pictures of it in space, it's silver,
almost chrome looking. Is that white a shroud over the entire command
module
that's jettisoned when the escape tower is jettisoned? If so, why? Seems
like
it's a lot of extra weight at launch. Just been wondering.


It's called the Boost Protective Cover. It was used to protect the command
module.

http://www.apollosaturn.com/boost.htm

You can actually note this in the movie Apollo 13, but they get the sequence
messed up.

They mention "BCP Clear" and then a few minutes later you see an exterior
shot of it being jettisoned.

(I believe you see it from the interior at the BCP Clear call when the other
windows suddenly allow light in)


--
Greg D. Moore http://greenmountainsoftware.wordpress.com/
CEO QuiCR: Quick, Crowdsourced Responses. http://www.quicr.net

  #3  
Old August 25th 12, 08:21 AM posted to sci.space.shuttle
Brian Gaff
external usenet poster
 
Posts: 2,312
Default Apollo Question

I think its just how the paint looks when more UV hits it actually. I used
to notice this effect when I could see, but in shadow it still tended to
look as one would expect.



Changing the subject slightly though, the LEM looked like it was build fro
gold foil and although i understand this was just the outside material and
used for insulation and mad protection, it certainly looked very fragile.
Just how fragile were the walls of the cabin section?

Brian

--
--
From the sofa of Brian Gaff -

Blind user, so no pictures please!
wrote in message
...
Been meaning to ask this for a while. While sitting on the pad, the Apollo
command module is white. When you see pictures of it in space, it's
silver,
almost chrome looking. Is that white a shroud over the entire command
module
that's jettisoned when the escape tower is jettisoned? If so, why? Seems
like
it's a lot of extra weight at launch. Just been wondering.



  #4  
Old August 26th 12, 02:21 AM posted to sci.space.shuttle
Brian Thorn[_2_]
external usenet poster
 
Posts: 2,266
Default Apollo Question

On Sat, 25 Aug 2012 08:21:30 +0100, "Brian Gaff"
wrote:

I think its just how the paint looks when more UV hits it actually. I used
to notice this effect when I could see, but in shadow it still tended to
look as one would expect.


No, its the BPC (Boost Protective Cover), which is jettisoned as part
of the Launch Escape System exposing the shiny Command Module we all
know and love...

Brian
  #5  
Old August 26th 12, 05:45 AM posted to sci.space.shuttle
[email protected]
external usenet poster
 
Posts: 82
Default Apollo Question

On Sat, 25 Aug 2012 20:21:45 -0500, Brian Thorn wrote:

On Sat, 25 Aug 2012 08:21:30 +0100, "Brian Gaff"
wrote:

I think its just how the paint looks when more UV hits it actually. I used
to notice this effect when I could see, but in shadow it still tended to
look as one would expect.


No, its the BPC (Boost Protective Cover), which is jettisoned as part
of the Launch Escape System exposing the shiny Command Module we all
know and love...

Brian


So, obvioulsy, the Launch Escape System isn't connected to the BPC, but to the
capsule and just projects through the cover. So my concern for unecessary weight
shouldn't be a concern at all looking at what the cover is made out of. Almost
seems funny given the work and material that goes into the rest of the command
module.
  #6  
Old August 29th 12, 08:52 AM posted to sci.space.shuttle
Alan Erskine[_3_]
external usenet poster
 
Posts: 1,026
Default Apollo Question

On 25/08/2012 5:21 PM, Brian Gaff wrote:
I think its just how the paint looks when more UV hits it actually. I used
to notice this effect when I could see, but in shadow it still tended to
look as one would expect.



Changing the subject slightly though, the LEM looked like it was build fro
gold foil and although i understand this was just the outside material and
used for insulation and mad protection, it certainly looked very fragile.
Just how fragile were the walls of the cabin section?

Brian


I've read that when the main hatch was re-pressurised, it bulged outward
quite audibly and visibly.
  #8  
Old August 30th 12, 04:34 PM posted to sci.space.shuttle
Bob Haller
external usenet poster
 
Posts: 3,197
Default Apollo Question

On Aug 29, 9:33*am, Jeff Findley wrote:
In article m,
says...



On 25/08/2012 5:21 PM, Brian Gaff wrote:
I think its just how the paint looks when more UV hits it actually. I used
to notice this effect when I could see, but in shadow it still tended to
look as one would expect.


Changing the subject slightly though, the LEM looked like it was build fro
gold foil and although i understand this was just the outside material and
used for insulation and mad protection, it certainly looked very fragile.
Just how *fragile were the *walls of the *cabin section?


I've read that when the main hatch was re-pressurised, it bulged outward
quite audibly and visibly.


The pressure hull of the LEM was aluminum so thin that it wouldn't take
much to accidentally put a hole in it. *Apollo astronauts were real men
who knew the risks, but flew anyway.

Jeff



thinner than a pop can
  #10  
Old September 12th 12, 06:49 AM posted to sci.space.shuttle
David Spain
external usenet poster
 
Posts: 2,901
Default Apollo Question

On 8/26/2012 12:45 AM, wrote:
So, obvioulsy, the Launch Escape System isn't connected to the BPC, but to the
capsule and just projects through the cover. So my concern for unecessary weight
shouldn't be a concern at all looking at what the cover is made out of. Almost
seems funny given the work and material that goes into the rest of the command
module.


Er, not so obviously. This didn't sound quite correct to me, so I went to this reference via a quick Google search:

http://www.apollosaturn.com/asnr/escape.htm

Sounds like there are two attach points to the Launch Escape Tower legs. One for the BPC and one to the CM. I quote:

"Tower Leg Attachment

The apex section of the boost cover is attached to the launch escape tower legs. A passive tension tie connects the apex of the
boost cover and the docking probe of the command module. During a normal launch, the thrust of the tower jettison motor pulls the
cover away and snaps this tension tie, leaving the probe with the command module. During an abort, however, the master events
[controller] and the lunar docking events sequence [controller] send signals which fire the ordnance devices that separate the
docking ring from the CM. When the launch escape assembly is jettisoned the tension tie then pulls the probe and docking ring away
with the boost protective cover.

The launch escape tower is made of titanium tubes of 2-1/2 and 3-1/2-inch diameter covered with Buna N rubber insulation to protect
it against the heat of the rocket motor exhaust. The four legs of the tower fit in wells in the forward structure of the command
module. They are [fastened] with studs and frangible (brittle) nuts. These nuts contain a small charge which breaks them to separate
the module from the tower when the launch escape assembly is jettisoned."

Then a little further down:

"Mounted atop the launch escape motor is the tower jettison motor, which is used in all missions to jettison the subsystem. The
jettison motor is a little over 4-1/2 feet long, about 26 inches in diameter, and weighs about 525 pounds. Its solid propellant also
is polysulfide. It burns for a little over 1 second and produces about 31,500 pounds of thrust. The motor has two fixed nozzles,
located 180 degrees apart, which project from its steel case at a downward and outward angle. These skewed nozzles produce a
resultant thrust vector angle of approximately 4 degrees which tips the tower and pulls it free of the CM."

Dave





 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Apollo question [email protected] Space Shuttle 9 April 27th 12 10:16 PM
Apollo 11 question GordonD History 25 September 21st 11 12:15 PM
Apollo 13 question Pat Flannery History 6 July 24th 06 01:54 AM
Apollo 11 question Pat Flannery History 2 July 18th 05 01:36 AM
Apollo One Question [email protected] History 29 December 23rd 04 11:29 PM


All times are GMT +1. The time now is 01:38 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 SpaceBanter.com.
The comments are property of their posters.