Agena target vehicle

Hi, can someone enlighten me on Gemimi/Agena?

The Agena was on some occasions used for boosting an attached Gemini
into a higher orbit, right? I didn't find any good diagram of the Agena,
but it seems to me that the docking port was in one end, and the rocket
engine in the other?

Does that mean that the Gemini was accelerated "backwards" during Agena
burn? I guess the Gemini must have attached nose-first to the end of the
Agena that was opposite the rocket I say "backwards" because of
things were the way I imagine, the acceleration force on the Gemini must
have been in the opposite direction of what it was during launch and
reentry?

TNX

Soren

In article ,
Soren Kuula wrote:
The Agena was on some occasions used for boosting an attached Gemini
into a higher orbit, right? I didn't find any good diagram of the Agena,
but it seems to me that the docking port was in one end, and the rocket
engine in the other?

That's right. The docking port and related equipment went in where the
Agena's payload was normally housed. And yes, the Agenas were used to
boost the Geminis on some of those flights.

Does that mean that the Gemini was accelerated "backwards" during Agena
burn?

Correct.
--
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"Soren Kuula" wrote in message
...
Hi, can someone enlighten me on Gemimi/Agena?

The Agena was on some occasions used for boosting an attached Gemini into
a higher orbit, right? I didn't find any good diagram of the Agena, but it
seems to me that the docking port was in one end, and the rocket engine in
the other?

The Agena "D" model was lauched by an Atlas booster for the Gemini program.
Here is a web page dedicated to the Agena. The Agena was used as an upper
stage for the Thor (Delta), Atlas and Titan boosters. The Agena was
origianlly deevloped for orbital photo-reconnaissance purposes (like
Corona). A very good color photo image of Agena-D is halfway down that web
page.
http://www.designation-systems.net/d...pp1/rm-81.html

Does that mean that the Gemini was accelerated "backwards" during Agena
burn?

Yes, the Gemini flew (or pushed) backwards !
This "switch engine" usage of the Agena is descibed in chapter the Gemini
reports.
http://www.hq.nasa.gov/office/pao/Hi...203/ch14-8.htm

I guess the Gemini must have attached nose-first to the end of the Agena
that was opposite the rocket I say "backwards" because of things
were the way I imagine, the acceleration force on the Gemini must have
been in the opposite direction of what it was during launch and reentry?

On the Shoulders of Titans: A Hisotry of Project Gemini by Barton C. Hacker
& James M. Grimwood can be found on-line.
http://www.hq.nasa.gov/office/pao/Hi...4203/cover.htm

Chapter 13 covers the Agena by Lockheed and Bell as well as the ATDA
developed by McDonnell (as a back-up) that was eventually used and named the
"Angry Alligator" by Tom Stafford - Gemini IX mission commander.
http://www.hq.nasa.gov/office/pao/Hi...203/ch14-6.htm

Pete Conrad & Dick Gordon's "high earth orbit"
http://www.hq.nasa.gov/office/pao/Hi...203/ch15-3.htm

TNX

Soren

Soren Kuula wrote:
Hi, can someone enlighten me on Gemimi/Agena?

The Agena was on some occasions used for boosting an attached Gemini
into a higher orbit, right? I didn't find any good diagram of the Agena,
but it seems to me that the docking port was in one end, and the rocket
engine in the other?

Does that mean that the Gemini was accelerated "backwards" during Agena
burn? I guess the Gemini must have attached nose-first to the end of the
Agena that was opposite the rocket I say "backwards" because of
things were the way I imagine, the acceleration force on the Gemini must
have been in the opposite direction of what it was during launch and
reentry?

Absolutely correct. For a photograph of the burn as seen by the crew,
and a brief description ("Because the Gemini and Agena docked nose to
nose, the forces experienced were eyeballs out as opposed to eyeballs in
for a launch from Earth."), see http://www.answers.com/topic/gemini-10 .

--
Dave Michelson

On Sun, 30 Oct 2005 15:20:29 +0100 "Soren Kuula" wrote:

The Agena was on some occasions used for boosting an attached Gemini
into a higher orbit, right? I didn't find any good diagram of the Agena,
but it seems to me that the docking port was in one end, and the rocket
engine in the other?

Yep. The Gemini docking adapter was placed in the position, that was
normally occupied by the payload on a satellite launch.

Does that mean that the Gemini was accelerated "backwards" during Agena
burn? I guess the Gemini must have attached nose-first to the end of the
Agena that was opposite the rocket I say "backwards" because of
things were the way I imagine, the acceleration force on the Gemini must
have been in the opposite direction of what it was during launch and
reentry?

You're right in every point you mentioned. The acceleration when
changing Gemini orbits by Agena boost was "eyeballs out", as you
described. There wasn't any other possibility.

see: http://www.hq.nasa.gov/office/pao/History/SP-4203/cover.htm
From chapter 15.3 I cite as an example: [...] At 40:30 hours into the
flight, in the 26th revolution, Conrad triggered the firing signal to
the target vehicle's main engine. For 26 seconds it belched a fiery
stream to add 279.6 meters per second to their speed. "Whoop-de-doo!"
Conrad yelled, "[that's] the biggest thrill of my life." Since they
faced the Agena, the acceleration forced the crew forward onto the
seat harnesses. They watched the great round ball of Earth recede.
[...]

cu, ZiLi aka HKZL (Heinrich Zinndorf-Linker)
--
"Abusus non tollit usum" - Latin: Abuse is no argument against proper use.

mailto: http://zili.de

"Soren Kuula" wrote in message
...
Hi, can someone enlighten me on Gemimi/Agena?

TNX
Soren

The models also give you an idea of perspective.
This model depicts the Gemini 11 spacecraft docked with an Agena target
vehicle with Astronaut Richard F. Gordon straddling the Agena as he attaches
a tether between the two spacecraft for an upcoming experiment, based on a
well known photo taken during the mission on September 13th, 1966
Here is actual photo
http://www.spaceistheplace.ca/gtaxidickgordon.jpg

Here are the model depictions
http://www.spaceistheplace.ca/space3.htm
http://www.spaceistheplace.ca/gta111.jpg
http://www.spaceistheplace.ca/gta112.jpg

http://my.execpc.com/~acasper/plastic5.htm

This rare model just sold on eBay yesterday
Item number: 6007171302

Peter Johnson model (halfway down)
http://mek.kosmo.cz/newware/nwphotos.htm

The Agena also had a role in the Mariner (Mars and Venus) and Ranger (Moon
photography).
Paired with the Atlas booster, Agena B was used in 1962 for the first two
Mariner flights (the Atlas stage malfunctioned during the Mariner 1 launch).
Atlas-Agena D, with an improved upper stage that could accept a greater
variety of payloads, launched the next three Mariners in 1964 and 1967.
http://www.astronautix.com/lvs/atlgenad.htm

http://www.spaceline.org/rocketsum/atlas-agena-d.html

gb

Soren Kuula wrote:
Hi, can someone enlighten me on Gemimi/Agena?

Thanks for all the answers. The Agena looks much bigger than it really
was, on pictures where there is nothing else to compare it to.

Must have been one sickening flight First, jammed into the couches,
then floating abuot for some time, then the eyeballs almost sucked of of
your face, and finally jammed into the couch again. Well OK if they find
some usable Geminis somewhere in a forgotten storage hangar, I'd still
like to try But on the other hand, I guess they'd be the only flyable
spacecraft in the country, and reserved for something else.

When one astronaut EVAed, what did the other one do? Also wore a
spacesuit? There was no airlock or any other compartment, was there?

Soren

"Soren Kuula" wrote in message
...
Soren Kuula wrote:
Hi, can someone enlighten me on Gemimi/Agena?

Thanks for all the answers. The Agena looks much bigger than it really
was, on pictures where there is nothing else to compare it to.

Must have been one sickening flight First, jammed into the couches,
then floating abuot for some time, then the eyeballs almost sucked of of
your face, and finally jammed into the couch again. Well OK if they find
some usable Geminis somewhere in a forgotten storage hangar, I'd still
like to try But on the other hand, I guess they'd be the only flyable
spacecraft in the country, and reserved for something else.

When one astronaut EVAed, what did the other one do? Also wore a
spacesuit? There was no airlock or any other compartment, was there?

Correct.

There is a fairly accurately depicted in the Tom Hanks produced mini-series
"From the Earth to the Moon" ... with Gemini 4 ... first US space walk by Ed
White and Jim McDivitt inside the capsule in his space suit.

McDivitt "repeated" this role in Apollo 9 (serving as commander) .. for the
first US EVA by 2 astronauts --- when Dave Scott made EVA from Comand Module
(Gumdrop) and Rusty Schweickart from the Lunar Module (Spider) for 37
minutes.

gb

Soren

Dave Michelson wrote:


Absolutely correct. For a photograph of the burn as seen by the crew,
and a brief description ("Because the Gemini and Agena docked nose to
nose, the forces experienced were eyeballs out as opposed to eyeballs in
for a launch from Earth."), see http://www.answers.com/topic/gemini-10 .


And McDonnell saw possibilities in that arrangement, using either a
Centaur or multiple Titan III transtages docked to the Gemini in the
same way to send it on a lunar trajectory:
http://www.astronautix.com/articles/bygemoon.htm

Pat

"gb" writes:


Yes, the Gemini flew (or pushed) backwards !
This "switch engine" usage of the Agena is descibed in chapter the Gemini
reports.
http://www.hq.nasa.gov/office/pao/Hi...203/ch14-8.htm


How many G's was the 'eyeballs out' firings?

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