Gemini 8 stuck thruster

What was the location of the thruster that failed and caused gemini 8 to go
out of control?

Was it on the capsule that reentered or one of the white adapter sections?
If it was the adapter how did nasa figure out what happened since it would
have been left in orbit or burned up on reentry?

thanks

joe

On Feb 17, 8:21 pm, "JOE HECHT" wrote:
What was the location of the thruster that failed and caused gemini 8 to go
out of control?

Was it on the capsule that reentered or one of the white adapter sections?
If it was the adapter how did nasa figure out what happened since it would
have been left in orbit or burned up on reentry?

thanks

joe

It was roll thrust no. 8, one of the 25-pound Orbit Atitude and
Maneuver System (OAMS) roll thrusters, that stuck. After they stopped
the roll, Armstrong and Scott did some troubleshooting to isolate the
bad thruster. The following diagram shows where the roll thrusters
were located in the rear (white) adapter section.

"http://history.nasa.gov/SP-4002/images/fig15.jpg"

I don't believe that an absolutely certain cause for the stuck
thruster was found, but failure analysis determined that that the most
likely cause was an electrical short circuit that allowed current to
flow through the coil of a solenoid valve.

- Ed Kyle

JOE HECHT wrote:
What was the location of the thruster that failed and caused gemini 8 to go
out of control?

Was it on the capsule that reentered or one of the white adapter sections?


It was one of the eight Orbit Attitude Control Thrusters at the base of
the equipment module:
http://nssdc.gsfc.nasa.gov/planetary...ni_diagram.gif

Pat

On Feb 18, 5:27 am, Pat Flannery wrote:
JOE HECHT wrote:
What was the location of the thruster that failed and caused gemini 8 to go
out of control?

Was it on the capsule that reentered or one of the white adapter sections?

It was one of the eight Orbit Attitude Control Thrusters at the base of
the equipment module:http://nssdc.gsfc.nasa.gov/planetary...ni_diagram.gif

Pat

......... shades of Apollo 1.

On Mon, 19 Feb 2007 21:28:20 -0600, scott wrote
(in article .com):

On Feb 18, 5:27 am, Pat Flannery wrote:
JOE HECHT wrote:
What was the location of the thruster that failed and caused gemini 8 to go
out of control?

Was it on the capsule that reentered or one of the white adapter sections?

It was one of the eight Orbit Attitude Control Thrusters at the base of
the equipment
module:http://nssdc.gsfc.nasa.gov/planetary...ni_diagram.gif

Pat

......... shades of Apollo 1.


Only in your deluded, paranoid fantasies.

--
You can run on for a long time,
Sooner or later, God'll cut you down.
~Johnny Cash

On Tue, 20 Feb 2007 07:23:48 -0600, Herb Schaltegger
wrote:

On Mon, 19 Feb 2007 21:28:20 -0600, scott wrote
......... shades of Apollo 1.

....Well, well, well, mommie's little baby decided to crawl out from
under his rock. Where've you been "scotty"? Out stalking NAA employees
in drag again?

Only in your deluded, paranoid fantasies.

....Yep. If only we could have both of them stuffed in a rubber room at
the funny farm. Wouldn't matter whether they got help or not, at least
they'd quit ****ing on Gus' memory. He really deserves better, which
is probably why we jump "scott's" **** every time he opens his mouth
and recites Betty's psychotic, paranoid dogma.

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

On Feb 18, 3:27 am, Pat Flannery wrote:
JOE HECHT wrote:
What was the location of the thruster that failed and caused gemini 8 to go
out of control?

Was it on the capsule that reentered or one of the white adapter sections?

It was one of the eight Orbit Attitude Control Thrusters at the base of
the equipment module:http://nssdc.gsfc.nasa.gov/planetary...ni_diagram.gif

Pat


The "Gemini Technical Summary" document states which thruster had a
problem and shows where it was located:

http://ntrs.nasa.gov/archive/nasa/ca...1968016105.pdf

PDF page 44 states that, "The problem was isolated to No. 8 OAMS
thruster which fired continuously because its circuitry failed in an
ON condition."

PDF page 143 contains a diagram that shows where OAMS thruster No. 8
was located.

From the diagram, it appears to be behind and to the lower left of
Command Pilot Neil Armstrong, at the base of the Gemini Equipment
Adapter section. It was one of the left roll thrusters.

Rusty

Rusty wrote:
From the diagram, it appears to be behind and to the lower left of
Command Pilot Neil Armstrong, at the base of the Gemini Equipment
Adapter section. It was one of the left roll thrusters.


What screwed things up was that they were supposed to be fired in pairs
set 180 degrees apart, firing just one meant the center of thrust didn't
pass through the center of rotation of the spacecraft, so instead of
simply rolling, it developed a wobbling motion.
The Apollo SM thruster quads were a big improvement on this concept of
control.
If Gemini had been designed right, those roll thrusters should have been
on the retro section with the other control thrusters, very near the
center of mass of the whole spacecraft.

Pat

Pat Flannery wrote:

If Gemini had been designed right, those roll thrusters should have
been on the retro section with the other control thrusters, very near
the center of mass of the whole spacecraft.

But why would that matter? Unless roll thrusters are fired in
opposition, there will be a net offset no matter where they are located
because they are not (and cannot!) be designed to direct their net
thrust through the vehicle's centre of mass.

BTW, I would claim that Gemini was "designed right" with the sole
exception of not having a method for intravehicular transfer of crew
between docked vehicles. However, back in 1961, it wasn't even remotely
a requirement. (And Block I Apollos didn't have that capability either.)

--
Dave Michelson

On Tue, 20 Feb 2007 19:15:48 -0600, Dave Michelson wrote
(in article 83NCh.1073902$5R2.698651@pd7urf3no):

Pat Flannery wrote:

If Gemini had been designed right, those roll thrusters should have
been on the retro section with the other control thrusters, very near
the center of mass of the whole spacecraft.

But why would that matter? Unless roll thrusters are fired in
opposition, there will be a net offset no matter where they are located
because they are not (and cannot!) be designed to direct their net
thrust through the vehicle's centre of mass.

Hence the concept of "moment" . . . :-)

--
You can run on for a long time,
Sooner or later, God'll cut you down.
~Johnny Cash