BBQ Roll question...

....Here's one that hit me this evening, and I'm surprised none of us
have ever asked this befo When the CSM stack was put into the
Passive Thermal Roll - or BBQ Roll - was it done clockwise or
counter-clockwise? And was there a preference, and if so, why?

OM
--
]=====================================[
] OMBlog - http://www.io.com/~o_m/omworld [
] Let's face it: Sometimes you *need* [
] an obnoxious opinion in your day! [
]=====================================[

OM wrote:
...Here's one that hit me this evening, and I'm surprised none of us
have ever asked this befo When the CSM stack was put into the
Passive Thermal Roll - or BBQ Roll - was it done clockwise or
counter-clockwise? And was there a preference, and if so, why?

Interesting question.

The Apollo 15 Flight Journal gives the impression that either was a
possibility.

--
Dave Michelson

it depended on how well done you wanted your barbecue ribs

Just joking!

"OM" wrote:

...Here's one that hit me this evening, and I'm surprised none of us
have ever asked this befo When the CSM stack was put into the
Passive Thermal Roll - or BBQ Roll - was it done clockwise or
counter-clockwise? And was there a preference, and if so, why?

Supplement 2 to the Apollo 8 Mission Report

http://ntrs.nasa.gov/archive/nasa/ca...1974072935.pdf

has a section on PTC starting on page 82 of the PDF file (page 6-1 of the original
doc.).

"PTC roll rate was introduced by five minus roll axis firings between GET
11:13:38 and 11:13:40."

"Minus roll" would be to the left or anticlockwise I believe?


--

Brian Lawrence

Wantage, Oxfordshire, UK

On Mon, 20 Feb 2006 15:42:32 -0000, "Brian Lawrence"
wrote:

"OM" wrote:

...Here's one that hit me this evening, and I'm surprised none of us
have ever asked this befo When the CSM stack was put into the
Passive Thermal Roll - or BBQ Roll - was it done clockwise or
counter-clockwise? And was there a preference, and if so, why?

Supplement 2 to the Apollo 8 Mission Report

http://ntrs.nasa.gov/archive/nasa/ca...1974072935.pdf

has a section on PTC starting on page 82 of the PDF file (page 6-1 of the original
doc.).

"PTC roll rate was introduced by five minus roll axis firings between GET
11:13:38 and 11:13:40."

"Minus roll" would be to the left or anticlockwise I believe?

....Yep, but the questions of why and was this SOP still remain.

OM
--
]=====================================[
] OMBlog - http://www.io.com/~o_m/omworld [
] Let's face it: Sometimes you *need* [
] an obnoxious opinion in your day! [
]=====================================[

"OM" wrote in message
news
On Mon, 20 Feb 2006 15:42:32 -0000, "Brian Lawrence"
wrote:

"OM" wrote:

...Here's one that hit me this evening, and I'm surprised none of us
have ever asked this befo When the CSM stack was put into the
Passive Thermal Roll - or BBQ Roll - was it done clockwise or
counter-clockwise? And was there a preference, and if so, why?

Supplement 2 to the Apollo 8 Mission Report


http://ntrs.nasa.gov/archive/nasa/ca...1974072935.pdf

has a section on PTC starting on page 82 of the PDF file (page 6-1 of the
original
doc.).

"PTC roll rate was introduced by five minus roll axis firings between
GET
11:13:38 and 11:13:40."

"Minus roll" would be to the left or anticlockwise I believe?

...Yep, but the questions of why and was this SOP still remain.

I'm thinking that on the unit circle angles are measured as anticlockwise =
positive. For example, so that sin ?/2 = 1. If, on the spacecraft, minus
roll is defined to be anticlockwise, I'm wondering what made them reverse
the normal practice.

"Brian Lawrence" wrote in message
...

http://ntrs.nasa.gov/archive/nasa/ca...1974072935.pdf

Rusty? Is that you?

I have this vague recollection that it was done clockwise
(from the astronaut sitting in the CM, looking forward,
viewpoint).

So it must have been done the other way on A13 when the LM provided
reaction control for both vehicles.

"Neil Gerace" wrote in message
...

"OM" wrote in message
news
On Mon, 20 Feb 2006 15:42:32 -0000, "Brian Lawrence"
wrote:

"OM" wrote:

...Here's one that hit me this evening, and I'm surprised none of us
have ever asked this befo When the CSM stack was put into the
Passive Thermal Roll - or BBQ Roll - was it done clockwise or
counter-clockwise? And was there a preference, and if so, why?

Supplement 2 to the Apollo 8 Mission Report


http://ntrs.nasa.gov/archive/nasa/ca...1974072935.pdf

has a section on PTC starting on page 82 of the PDF file (page 6-1 of the
original
doc.).

"PTC roll rate was introduced by five minus roll axis firings between
GET
11:13:38 and 11:13:40."

"Minus roll" would be to the left or anticlockwise I believe?

...Yep, but the questions of why and was this SOP still remain.

I'm thinking that on the unit circle angles are measured as anticlockwise
= positive. For example, so that sin ?/2 = 1. If, on the spacecraft, minus
roll is defined to be anticlockwise, I'm wondering what made them reverse
the normal practice.

You are getting to complicated. Its just a number line -5 -4 -3 -2 -1 0 1 2
3 4. -5 degrees is to the left.