MA-8 FLight Plan questions.

In article ,
adam bootle wrote:
Im not sure if I understand correctly but does that mean that Schirra has to
report when he is at four fifths of his needed velocity ?

It sounds more like he's being asked to report what velocity he's at,
at a time when he's supposed to be at four-fifths of his needed velocity.
--
"Think outside the box -- the box isn't our friend." | Henry Spencer
-- George Herbert |

"adam bootle" ) writes:
Thanks Andre and Derek,

You're welcome.

You learn something new every day, I thought the common bulkhead shared
by the LOX and the RP-1 tanks was developed for the Apollo Program but I
looked at the diagrams and see that it was in use years before a Saturn
booster ever flew !

Cool, innit ? :-)

Cheers guys..........Adam

"Derek Lyons" wrote in message
...

Check this site for a few diagrams that make the whole thing clearer.
http://www.geocities.com/atlas_missile/diagrams.html

Andre

--
" I'm a man... But, I can change... If I have to... I guess. "
The Man Prayer, Red Green.

In article ,
Pat Flannery wrote:
...It was the LOX/LH2 stages that had common bulkheads, and
that was indeed a significant development specific to Apollo -- those
common bulkheads had to be insulated to control LH2 boiloff.

Could the low LH2 temp have solidified the LOX?

Possibly some, but in practice, the heat capacity of liquid hydrogen is so
low that you'd probably boil off most or all of the LH2 before very much
of the LOX solidified.

An interesting sidelight on that is that the Atlas common bulkhead was
*not* insulated -- just one thin sheet of stainless steel between the
tanks, with LOX above and RP-1 below. Early prototypes did have some
insulation on the bulkhead, but they eventually decided it was unnecessary
and deleted it.

For real fun, do a common bulkhead between hypergolic propellants:
http://www.astronautix.com/lvs/pros824f.htm

Yeah, if memory serves there's one of those in the Delta II second stage
as well. That would make you a wee bit fussy about manufacturing, not
that common bulkheads aren't a fussy manufacturing issue anyway...
(The H-II second stage had a common bulkhead; the H-IIA second stage
does not, partly to make it easier to build.)
--
"Think outside the box -- the box isn't our friend." | Henry Spencer
-- George Herbert |

Peter Stickney wrote:

You're talking about the two small motors on the upper stage,
right? (Geocities (Rhymes with Atrocities) and their low bandwidth
limits have struck again.)
As I remember it, those are the verniers, for final velocity trim
after the second stage cuts out.


No, they are called out as "staging rockets" on the drawing; there are
also four small vernier nozzles besides the two staging rockets that are
mounted externally at ninety degree angles to one another.
I'll link to the specific illustration, maybe that will help. The
staging rockets are #5; the vernier nozzles are #6:
http://www.geocities.com/titan_1_mis...agram_tall.gif

After all, you couldn't put 'em down
at the base, like an Atlas or Thor, /cause you're dropping th efist
stage off. The verniers would have to be on the second stage.



The big problems with lighting the second stage with the first stage
still attached is that the second stage engine bell is only a couple of
feet above the top of the first stage LOX tank upper dome, and unlike
the Titan II (or the Soviet ones) there is no way for the second stage
engine exhaust to exit from the interstage structure...you can try it,
but I think it's going to explode the interstage area when the motor
starts to ignite. Here's a cutaway showing the internal layout:
http://www.geocities.com/titan_1_mis..._1_cutaway.gif
And two diagrams of the second stage motor showing how it's connected to
the four vernier nozzles:
http://www.geocities.com/titan_1_mis...age_engine.gif
http://www.geocities.com/titan_1_mis...age_engine.gif
I assume that the staging rockets are solid fueled, and that you light
the second stage as they are pushing it away from the first one and
keeping the propellants seated.

Pat

In article ,
Pat Flannery writes:


Peter Stickney wrote:
So, they went with what
they called "Fire in the Hole" staging - the upper stage motors were
lit before the lower stage finished burning, and before stage
separation. This was carried on with the Titan II.



Didn't Titan 1 use ullage motors, and Titan II the "fire in the hole"?
http://www.geocities.com/titan_1_missile/Facts.html (see number 5)
The Soviets liked that concept so much that it got used on quite a few
rockets, including the Proton and N-1.

You're talking about the two small motors on the upper stage,
right? (Geocities (Rhymes with Atrocities) and their low bandwidth
limits have struck again.)
As I remember it, those are the verniers, for final velocity trim
after the second stage cuts out. After all, you couldn't put 'em down
at the base, like an Atlas or Thor, /cause you're dropping th efist
stage off. The verniers would have to be on the second stage.

--
Pete Stickney

Without data, all you have are opinions

On Mon, 31 Jan 2005, adam bootle wrote:


Just been having a read of the MA-8 Flight Plan, and have a few things
I'd like to get straight.

When Schirra has to report BECO does the B stand for booster ? Similarly
at SECO does S stand for Single ?

The Atlas was a stage and a half design with 3 engines in a line. At about
130 seconds the two outboards shutdown and then a couple of seconds later
they are jettisoned along with the shroud holding them. The Atlas
continues on with the center engine known as the substainer.

If you want to see this in action you can use my Mercury Addon for orbiter
sim. You can download everything you need at
http://sourceforge.net/projects/mscorbaddon. There are older versions if
your graphics card isn't up to running the newest versions.


At around 0:04:30 into the flight, Schirra has to report whether "V/VR is
over .8" Is this some kind of speed or G force thing ? Is there anyone
out there who can explain it in laymans terms (for "laymans" read Forrest
Gump)


The explanation for this was pointed out earlier in the thread (V/VR being
the ratio of current velocity against orbital velocity). However what is
in error that the call was not made by the astro but by mercury control.
If you look to the left of the call in the flight plan you will see MCC-:
Those are call made by capcom in Mercury Control. So by 4:30 Mission
Control is to tell Schirra how he is doing on the climb
to orbit.

I wondered about your question because I spent the better part of a year
trying to code an accurate simulation of the panel. When the explanation
of V/VR was offered I knew something wasn't right because there isn't an
instrument that would allow the astro to give that kind of reading.
Pitch Angle yes but not velocity. Hence I checked the flight plan and
found the MCC notation.

I want to thank Henry for that explanation of V/VR. I am currently
building a software simulation of the MCC and one of the plot boards
charts V/VR and I wondered what it meant.

Rob Conley

Here is a screenshot montage of all the panel in the project mercury
simulation I wrote.

http://www.ibiblio.org/mscorbit/sour...nelGraphic.jpg

This is more screenshots

http://projectmercury5.moonport.org/

Rob Conley

Robert Conley wrote:


Here is a screenshot montage of all the panel in the project mercury
simulation I wrote.

http://www.ibiblio.org/mscorbit/sour...nelGraphic.jpg



Looks really sharp.... what exactly is the periscope showing?

Pat

On Wed, 2 Feb 2005, Pat Flannery wrote:


Here is a screenshot montage of all the panel in the project mercury
simulation I wrote.

http://www.ibiblio.org/mscorbit/sour...nelGraphic.jpg



Looks really sharp.... what exactly is the periscope showing?


The view you are see in the graphic is what you would see looking out of the
scope while on the launch pad. Basically a 130 degree fish eye view of the
surroundings.

Before the launch the periscope is already extended and the astronaut can
see out. Before the final series of countdowns the scope is retracted.

This was a source of a problem for Alan Shephard on Freedom 7 MR-3. The
sun was shining into the scope so he put the grey filter on. Later, after
the scope retracted, he tried to reset it back to normal but his hand
bumped the abort handle and so he stopped trying to change it back and let
it alone.

When he got to orbit and did his earth observations he was looking through
that grey filter and the view was pretty much a greyscale. (Which
a detail that From the Earth to Moon got right in Episode 1). Because the
capsule had these little portholes he never got a good view until Apollo
14.


Here is a screen shot of looking through the scope into the sahara desert.

http://projectmercury5.moonport.org/thumbs/thumb17.jpg

Rob Conley

Robert Conley wrote:


Looks really sharp.... what exactly is the periscope showing?


The view you are see in the graphic is what you would see looking out
of the scope while on the launch pad. Basically a 130 degree fish eye
view of the surroundings.


Okay, I figured it out now.
Is there going to be a "You be Ham" add-on module that has the banana
pellet reward machine and the light board with the levers you have to
pull? You could maybe even wire in the malfunctioning shock system to
give the player of the simulation a real feel for the flight.
A great extra feature of this would be that you could try to bite the
recovery crew, and hurl feces at reporters as they try to interview you
after the flight. "Look! Walter Cronkite! Double points!". ;-)

Pat