A Space & astronomy forum. SpaceBanter.com

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

Light This Candle



 
 
Thread Tools Display Modes
  #1  
Old May 7th 04, 09:13 PM
Rick DeNatale
external usenet poster
 
Posts: n/a
Default Light This Candle

I guess that it might be off-topic to this newsgroup G, but I'm a little
surprised that no one has talked about the recently released biography of
Alan Shepard by Neal Thompson.

I just finished it a couple of days ago, and was wondering what some of
you think about it.

Reading the back cover blurb, Homer Hickam says that although he thought
he "knew pretty much everything about the history of the American space
effort" he "learned something new" on "nearly every page of this fine
book." After reading it I wonder how much I learned is true, based on
some of the technical statements.

For example on page 255 during the description of his Freedom 7 flight I
"learned:"

"Shepard then had to align the capsule at the precise angle so that the
asbestos-covered bottom of the capsule would absorb the intense heat to
come."

Asbestos-covered?????

"If he was off by just a degree or two, the capsule could be thrown
dangerously far off course."

True? The Mercury spacecraft didn't generate much lift did it? And, it
doesn't seem to me that there would be very much to affect what was
basically a ballistic trajectory.

Then on page 328 we have:
"The soul-searching, investigations, shake-ups, and restructuring that
had occurred throughout NASA after the Apollo 1 disaster resulted in a
completely redesigned Apollo capsule -- and a ridiculously huge new
rocket. Apollo flights scheduled to begin in October of 1968 would be
boosted from earth atop a Saturn 5 rocket, which Wernher von Braun had
spent nearly a decade creating."

I never new that the Saturn V hadn't been considered for Apollo before the
fire, nor that Apollo 7 had used a Saturn V rather than a Saturn Ib!!!!!

And on pp385-86 "Shepard was disgusted by the Challenger tragedy, which
was caused by a faulty valve."

Faulty valve?????

I hope that the author got more right in his description of the
personalities, but I wasn't impressed by his fact-checking on the
technical details.

Comments?
  #2  
Old May 8th 04, 03:03 AM
John Whisenhunt
external usenet poster
 
Posts: n/a
Default

I finished the book a couple of weeks ago. Sure, it's full of historical and
technical inaccuracies and contains a lot of heresay, but I think Thompson
was going for a character study, as in "what was Shepard really like."
Everyone knows the "Smilin' Al versus the Icy Commander" duality, so he
probably figured we needed to fill in the middle portions of Al's psyche.
Reading it this way, and not as history, I found it to be a pretty good
book.

JW

Whizzospace
http://whizzospace.com




----== Posted via Newsfeed.Com - Unlimited-Uncensored-Secure Usenet News==----
http://www.newsfeed.com The #1 Newsgroup Service in the World! 100,000 Newsgroups
---= 19 East/West-Coast Specialized Servers - Total Privacy via Encryption =---
  #3  
Old May 8th 04, 03:09 AM
Derek Lyons
external usenet poster
 
Posts: n/a
Default

"John Whisenhunt" wrote:
I finished the book a couple of weeks ago. Sure, it's full of historical and
technical inaccuracies and contains a lot of heresay, but I think Thompson
was going for a character study, as in "what was Shepard really like."
Everyone knows the "Smilin' Al versus the Icy Commander" duality, so he
probably figured we needed to fill in the middle portions of Al's psyche.
Reading it this way, and not as history, I found it to be a pretty good
book.


How do you know it's a reasonable illumination of this facet, when
it's so filled with other inaccuracies?

D.
--
Touch-twice life. Eat. Drink. Laugh.
  #5  
Old May 8th 04, 05:58 AM
Henry Spencer
external usenet poster
 
Posts: n/a
Default

In article ,
Rick DeNatale wrote:
"If he was off by just a degree or two, the capsule could be thrown
dangerously far off course."

True? The Mercury spacecraft didn't generate much lift did it?


In fact, none. It was balanced to put the center of mass on the
centerline, avoiding generating any lift... and if memory serves, reentry
was normally done in a slow roll so that any residual lift would average
to zero and the trajectory would be purely ballistic.

And, it
doesn't seem to me that there would be very much to affect what was
basically a ballistic trajectory.


Correct. For the orbital Mercury flights, the *retrofire* attitude had to
be moderately precise to come down at the planned point -- although the
nominal retrofire attitude was chosen mostly to minimize sensitivity to
attitude errors -- but during reentry, the spacecraft was basically stable
in only one position. The main attitude-control issue during reentry was
damping out oscillations, and that was more for crew comfort than anything
else. (Both Glenn and Carpenter ran out of attitude-control fuel midway
through descent, and were none the worse for it.)

Shepard did do a retrofire, with careful attitude control during it, but
that was a rehearsal for the orbital flights rather than anything that
mattered to his flight. It sounds like the writer did a bit of research
but not as much as he should have; he didn't really grasp the differences
between the suborbital and orbital flights.
--
MOST launched 30 June; science observations running | Henry Spencer
since Oct; first surprises seen; papers pending. |
  #6  
Old May 8th 04, 11:27 AM
adam bootle
external usenet poster
 
Posts: n/a
Default

Most noticable place I have seen this is on the Apollo 10 CM at the Science
Museum in London, UK. It's displayed in such a way as most of the heat
shield is visible.

Adam


"OM" om@our_blessed_lady_mary_of_the_holy_NASA_researc h_facility.org wrote

...One clue as to whether or not a conical, rear-end-down capsule has
any lift capabilites designed into it is to examine the heat shield
after reentry. If the striations and scoring from the reentry heat do
not appear to radiate from the dead center of the shield, then it's a
sure sign the C/M is offset to induce lift during reentry. You'll see
it dead center on Mercury heat shields, but obviously offset on
Gemini.

OM



  #7  
Old May 8th 04, 11:52 AM
OM
external usenet poster
 
Posts: n/a
Default

On Fri, 07 May 2004 16:13:02 -0400, Rick DeNatale
wrote:

True? The Mercury spacecraft didn't generate much lift did it? And, it
doesn't seem to me that there would be very much to affect what was
basically a ballistic trajectory.


....Correct. In order for the reentry to be a purely ballistic one, the
Mercury capsule & heatshield were designed so that the the center of
mass was smack dab right on on the middle of the heat shield. This
would eliminate any lift characteristics from the shield durign
reentry. In addition, there was a slow roll induced during reentry so
that any lift that might still result would be averaged out and
nulled.

....One clue as to whether or not a conical, rear-end-down capsule has
any lift capabilites designed into it is to examine the heat shield
after reentry. If the striations and scoring from the reentry heat do
not appear to radiate from the dead center of the shield, then it's a
sure sign the C/M is offset to induce lift during reentry. You'll see
it dead center on Mercury heat shields, but obviously offset on
Gemini.

OM

--

"No ******* ever won a war by dying for | http://www.io.com/~o_m
his country. He won it by making the other | Sergeant-At-Arms
poor dumb ******* die for his country." | Human O-Ring Society

- General George S. Patton, Jr
  #8  
Old May 8th 04, 05:12 PM
OM
external usenet poster
 
Posts: n/a
Default

On Sat, 8 May 2004 11:27:49 +0100, "adam bootle"
wrote:

"OM" om@our_blessed_lady_mary_of_the_holy_NASA_researc h_facility.org wrote

...One clue as to whether or not a conical, rear-end-down capsule has
any lift capabilites designed into it is to examine the heat shield
after reentry. If the striations and scoring from the reentry heat do
not appear to radiate from the dead center of the shield, then it's a
sure sign the C/M is offset to induce lift during reentry. You'll see
it dead center on Mercury heat shields, but obviously offset on
Gemini.


Most noticable place I have seen this is on the Apollo 10 CM at the Science
Museum in London, UK. It's displayed in such a way as most of the heat
shield is visible.


....One of the photos on my A17 page shows the striations, but not as
clearly as it should. The Gemini ones on the Gordo Cooper's Used
Spacecrafts page shows them better. One of the things I plan to do in
the next few months is to take my Canon Digital Rebel down to Space
Center Disney and redo quite a few of the photos from my disasterous
trip pages. Of course, the only shots I still can't add are the mug
shots of the two ghetto thugs who robbed me at gunpoint across the
street from the Outpost. I'll just simply make up for that by
including shots from inside the outpost this time.

OM

--

"No ******* ever won a war by dying for | http://www.io.com/~o_m
his country. He won it by making the other | Sergeant-At-Arms
poor dumb ******* die for his country." | Human O-Ring Society

- General George S. Patton, Jr
  #10  
Old May 8th 04, 06:50 PM
Rick DeNatale
external usenet poster
 
Posts: n/a
Default

On Sat, 08 May 2004 04:58:32 +0000, Henry Spencer wrote:

In article ,
Rick DeNatale wrote:
And, it
doesn't seem to me that there would be very much to affect what was
basically a ballistic trajectory.


Correct. For the orbital Mercury flights, the *retrofire* attitude had to
be moderately precise to come down at the planned point -- although the
nominal retrofire attitude was chosen mostly to minimize sensitivity to
attitude errors -- but during reentry, the spacecraft was basically stable
in only one position.


Due to the spring-loaded destabilizing flap which was deployed at tower
separation, and prevented a heatshield up aerodynamically stable mode.

The flap also covered the forward (or probably more technically accurately
aft) horizon sensor in the antenna cannister. It's one of those simple
mechanical designs which showed up in early "rocket science." Another
example I really like was the way that the nose fairing panels were
secured in the Bumper-WAC, they were actually held together with something
like sturdier versions of the hook fasteners used on gates, which where in
the path of the WAC Corporal's fins When the WAC fired it just knocked
them out of the way. I found some diagrams of this when I was searching
in the NASM library and thought "what a cool design!"
 




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
Light year distance question Tony Sims Technology 7 April 29th 05 04:41 PM
All technology outdated betalimit Policy 0 September 20th 04 03:41 PM
All technology outdated betalimit Policy 0 September 20th 04 03:41 PM
Light pollution. Was: Exterior House Lighting N9WOS Amateur Astronomy 26 February 10th 04 05:03 AM
Milky Way's Big Bang Giovanni Astronomy Misc 30 January 6th 04 11:32 AM


All times are GMT +1. The time now is 09:37 AM.


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.