Apollo 8 radio transcript

[tkx]

I'm trying to find a portion of the Apollo 8 radio transcript - the
part that says "you are go for the Moon." At least I'm pretty sure it
was Apollo 8, unless CapComs uttered that phrase for TLI on other
flights.

Does anyone have a verbatim transcript of that passage, including at
what time in the mission it was sent?

T

[uray]

On Mon, 11 Aug 2003 19:51:36 -0500, Homer J. Fong wrote:

> In article >, tkx
> > wrote:
>
>> The quote isn't there! I looked over the TLI pages for the Apollo 8
>> flight journal, and the only words from Houston are "you are go for
>> TLI."
>>
>> So did they say "you are go for the moon?" Or is that just Apollo
>> mythology, or creative license from the writers of "From the Earth to
>> the Moon?"
>>
>> T
>
> The only way they *ever* put it was "you're go for TLI"...I've never
> seen "From the Earth to the Moon" (I know...I should be flogged :) ) --
> how did they put it in the miniseries?

I believe they did add the "You are go for the Moon" in the miniseries. I
suspect I never really noticed it because that's always what I was
thinking when I heard the words :-)

uray

[Kent Betts]

Now here is an odd thing. Once they did the Trans Lunar Injection, the cabin
air went to 100% oxygen. Thought that went out with Apollo 1. Learn something
every day.
http://history.nasa.gov/ap08fj/03day1_green_sep.htm
-------
003:14:29 Borman: You got any reading on that O2 flow?

003:14:52 Collins: We're reading about the same as we were before that oxygen
flow. The reason it's that high is due to the cabin gas changeover. According to
Apollo 7, if your data repeats theirs, you can expect it to be high for another
few hours.

003:15:10 Borman: Roger. Thank you

[On the ground, prior to flight, the Apollo Command Module has an atmosphere
which is maintained at 60% oxygen and 40% nitrogen. This mixture is sufficient
to inhibit the kind of oxygen-fed fire that claimed the lives of the Apollo 1
crew. Once in space, the mixed cabin air is replaced with pure oxygen, supplied
from two tanks in the Service Module.]
-------

[Doug...]

In article >,
says...
> Now here is an odd thing. Once they did the Trans Lunar Injection, the cabin
> air went to 100% oxygen. Thought that went out with Apollo 1. Learn something
> every day.

The cabin air went to 100% oxygen beginning about two minutes into the
flight. As the Saturn rose, the two-gas cabin air was vented to outside
ambient pressure, until the pressure reached about 8 psi. The venting
was reduced to a much slower flow at this point, with replenishment
coming solely from onboard oxygen tanks. By the time the Apollo was in
orbit (roughly 12 minutes into the flight for a Saturn V launch, or about
six and a half minutes in for a Saturn IB flight), the atmosphere that
had been contained in the CM on the pad was nearly purged (trace amounts
of nitrogen left), with a *very* slow vent and replenishment continuing
for several more minutes to purge the rest of the nitrogen, resulting in
a 100% oxygen cabin atmosphere at about five psi. During all of this,
the crew of course remained in their suits, wearing helmets and gloves,
breathing pure oxygen. This was all done to prevent nitrogen bubbles
causing the "bends" at the 5 psi cabin pressure.

Apollo was designed to operate at 5 psi with a pure oxygen atmosphere for
many different reasons:

1) Weight. The cabin would have to have been built more strongly (read:
more heavily) to maintain higher pressures while in space.

2) Complexity. A two-gas system requires complex regulators and cabin
gas analyzers to maintain the proper balance of gasses. The Shuttle can
afford to lift this weight, since it's designed with a lot of performance
pad. But Apollo was going to the Moon, and that meant you wanted to keep
the weight of basic systems to an absolute minimum. Apollo operated at
the limits of its performance capabilities -- to add the weight and
complexities of a two-gas atmosphere in-flight would have seriously
compromised it.

3) EVA/suited operations. The pressure suits operated in vacuum at
between 3.5 and 4 psi pure oxygen (pretty much the minimum pressure of
oxygen required to keep a human alive and functioning). Keeping the
cabin pressure at 5 psi meant you could go on the suit circuit almost
immediately, if the cabin depressurized (intentionally or not), and not
suffer any of a variety of ill effects from sudden pressure changes.

Yes, all *ground testing* of the CSM after the Fire was done with a
mixed-gas atmosphere, provided by ground support equipment. But the
rationales for flying with a pure oxygen atmosphere never changed, and
were strong enough to keep the design going throughout the entire Apollo
program. In fact, the first American manned spacecraft to fly with a
two-gas system was Skylab, and it operated at about six psi with an 80%
oxygen atmosphere.

--

Do not meddle in the affairs of dragons, for | Doug Van Dorn
thou art crunchy and taste good with ketchup |