"blow the hatches" on Gemini

I'm reading yet another moon-walker biography. This time it is Rocketman
(Pete Conrad). It's a good read, a better read than First Man. (Perhaps
because Conrad and Armstrong are at opposite ends of the "colorful"
spectrum.)

One minor annoyance is a flurry of minor vocabulary errors. That makes
it hard for me to belive some of the minor factual points in the book.

At the end of Gemini 5, bobbing with the waves after splashdown: "The
chopper could come pull the whole thing [I.e., the Gemini 5 spacecraft],
Cooper and Conrad inside, and deposit them right on the deck of the
carrier or any of the destroyers coming there way. Or they could blow
the hatch, climb out, and let the frogmen help them into the harness to
be pulled up like a gaffed tuna. Looks fun. Isn't."

Could the Gemini hatches be blown, or is this a confusion with Mercury?
(The original does say "hatch" -- singular. Presumably, both hatches
were nearly identical save for mirror-image symmetry.)

Destroyer? Was this really a possibility? Would it be used for any
condition short of the carrier suddenly sinking as the spacecraft was
recovered?
--
Kevin Willoughby lid

In this country, we produce more students with university degrees
in sports management than we do in engineering. - Dean Kamen

Kevin Willoughby wrote:

I'm reading yet another moon-walker biography. This time it is Rocketman
(Pete Conrad). It's a good read, a better read than First Man. (Perhaps
because Conrad and Armstrong are at opposite ends of the "colorful"
spectrum.)

One minor annoyance is a flurry of minor vocabulary errors. That makes
it hard for me to belive some of the minor factual points in the book.

At the end of Gemini 5, bobbing with the waves after splashdown: "The
chopper could come pull the whole thing [I.e., the Gemini 5 spacecraft],
Cooper and Conrad inside, and deposit them right on the deck of the
carrier or any of the destroyers coming there way. Or they could blow
the hatch, climb out, and let the frogmen help them into the harness to
be pulled up like a gaffed tuna. Looks fun. Isn't."

Could the Gemini hatches be blown, or is this a confusion with Mercury?
(The original does say "hatch" -- singular. Presumably, both hatches
were nearly identical save for mirror-image symmetry.)

Yes. absolutely. How else do you think the ejection seats were going to
work?

Destroyer? Was this really a possibility? Would it be used for any
condition short of the carrier suddenly sinking as the spacecraft was
recovered?

Sure - Destroyers are faster than Carriers, and more maneuverable.
If you're searching for a capsule that landed away from its expected
impact point, and you need to cover a lot of sea, a screen of Destroyers
is what's going to get used.
If you're dealing with a potentially sinking capsule, and the recovery
helicopter (SH-3s this time, with the ASW gear stripped out,
can lift the capsule. (Hmm - let's see - SH-3A - Max Lift 'bout 7,000# for
a radius of 100 miles from the takeoff point, Gemini weight, about 4500#,
very, very do-able, even with some water sloshed in)

--
Pete Stickney
Without data, all you have is an opinion

Gemini hatches could be blown off. This was designed mainly for the
ejection seats that Gemini had. There was a window during the ascent
where the ejection seats were the primary abort mechanism.

The closest any Gemini mission came to using the ejection seats was
during the 2nd aborted lanuch of Gemini 6 when the Titan's engine cut
off. While the clock started, Schirra didn't feel any motion and
concluded it was a engine cutoff. Saving the rocket and the mission
which was launched several days later to meet up with Gemini 7 in
orbit.

The ejection seats could also be used in the event of a problem with
the main parachute not working.

Kevin Willoughby wrote:

Could the Gemini hatches be blown, or is this a confusion with Mercury?
(The original does say "hatch" -- singular. Presumably, both hatches
were nearly identical save for mirror-image symmetry.)

The reference to blowing a single hatch certainly sounds like confusion
on the part of the writer who finished the book.

Destroyer? Was this really a possibility? Would it be used for any
condition short of the carrier suddenly sinking as the spacecraft was
recovered?

Recall that the destroyer USS Mason picked up Gemini 8 after the early
end of the mission. Here's a photo:

http://science.ksc.nasa.gov/mirrors/...8/10074314.jpg

--
Dave Michelson

On 28 May 2006 21:30:46 -0700, "Robert Conley"
wrote:

Gemini hatches could be blown off. This was designed mainly for the
ejection seats that Gemini had. There was a window during the ascent
where the ejection seats were the primary abort mechanism.

Were there any other abort mechanisms on the Gemini/Titan?
---
Replace you know what by j to email

Jud McCranie wrote:
On 28 May 2006 21:30:46 -0700, "Robert Conley"
wrote:

Gemini hatches could be blown off. This was designed mainly for the
ejection seats that Gemini had. There was a window during the ascent
where the ejection seats were the primary abort mechanism.

Were there any other abort mechanisms on the Gemini/Titan?

Abort modes changed as the launch vehicle gained altitude and velocity.

Mode 1, ejection seats - from pad to 70,000 feet;

Mode 2, booster shutdown/retrosalvo - 70,000 to approximately 522,000 feet;

Mode 3, booster shutdown/normal separation - from approximately 522,000
feet until last few seconds of powered flight.

--
Dave Michelson

Dave Michelson wrote:

Abort modes changed as the launch vehicle gained altitude and velocity.

Mode 1, ejection seats - from pad to 70,000 feet;

Mode 2, booster shutdown/retrosalvo - 70,000 to approximately 522,000 feet;

Mode 3, booster shutdown/normal separation - from approximately 522,000
feet until last few seconds of powered flight.


That's the theory..

But, in practice, was an on-the-pad-abort survivable on Gemini? Various
stories are a bit contradicting, it sounds like "yes, you could eject on
the pad, but it would be suicide". It is doubtfully whether you would
reach enough altitude to safely open the parachute...

Regards,

Geert

Dave Michelson wrote:

Abort modes changed as the launch vehicle gained altitude and velocity.

Mode 1, ejection seats - from pad to 70,000 feet;

Mode 2, booster shutdown/retrosalvo - 70,000 to approximately 522,000 feet;

Mode 3, booster shutdown/normal separation - from approximately 522,000
feet until last few seconds of powered flight.


That's the theory..

But, in practice, was an on-the-pad-abort survivable on Gemini? Various
stories are a bit contradicting, it sounds like "yes, you could eject on
the pad, but it would be suicide". It is doubtfully whether you would
reach enough altitude to safely open the parachute...

Regards,

Geert

In article ,
Kevin Willoughby wrote:
Could the Gemini hatches be blown, or is this a confusion with Mercury?

Yes and no and kinda. They couldn't be jettisoned, but the ejection
system included pyrotechnic actuators -- hot-gas pistons -- to unlatch and
open the hatches very quickly. As each hatch actuator finished its
stroke, the movement of the piston uncovered vent ports which released hot
gas into the igniters of the seat propulsion system.

For that last reason, among others :-), I think the hatches were opened
manually after splashdown.

(The original does say "hatch" -- singular. Presumably, both hatches
were nearly identical save for mirror-image symmetry.)

Correct.

Destroyer? Was this really a possibility? Would it be used for any
condition short of the carrier suddenly sinking as the spacecraft was
recovered?

As witness Apollo 8, there weren't carriers covering every possible
recovery area.

Kevin Willoughby lid
In this country, we produce more students with university degrees
in sports management than we do in engineering. - Dean Kamen

That quote was a Congressbozo's stupid mistake -- the US graduates more
than a hundred times as many engineers as sports managers each year.
--
spsystems.net is temporarily off the air; | Henry Spencer
mail to henry at zoo.utoronto.ca instead. |

In article ,
Jud McCranie wrote:
...There was a window during the ascent
where the ejection seats were the primary abort mechanism.

Were there any other abort mechanisms on the Gemini/Titan?

They would have liked to rely exclusively on the seats, but the speed and
altitude just got too high later in ascent. After a certain point, you
separated the spacecraft from the launcher and stayed with the spacecraft,
at least until you were down lower and slower. (Jet fighters tend to work
the same way -- very few supersonic fighters have ejection seats that are
cleared for operation over the aircraft's entire flight envelope.)

The nominal procedure after such an abort was to ride the spacecraft down
to a normal landing, in fact, but the seats were always available if
things were too badly messed up for that.

(Similarly, Gemini had no reserve parachute -- if the main chute didn't
deploy properly, you ejected.)
--
spsystems.net is temporarily off the air; | Henry Spencer
mail to henry at zoo.utoronto.ca instead. |