Apollo service module question

Jeff Findley wrote:
"
savings.
The grid floor work made it possible for the astronauts to have shoes
which could look them in place if need be...solid floors might have needed
Velcro like in "2001" or the magnetic boots of golden age sci-fi.

And they helped with airflow, which is a *good thing* when you depend on a
handful of fans to supply you with fresh air to breathe.

Yeah, I hadn't thought of that aspect of the grid floor, but it
certainly would help with airflow. The airflow problem is one that
seldom gets mentioned in regards to microgravity. Theoretically, it
would be possible for you to suffocate in your sleep from the bubble of
exhaled CO2 surrounding you if there is no gas movement due to the lack
of the thermal upwelling of the cabin atmosphere, or the denser CO2
settling towards the floor.


Pat

Pat Flannery writes:

Jeff Findley wrote:
"
savings.
The grid floor work made it possible for the astronauts to have shoes
which could look them in place if need be...solid floors might have
needed Velcro like in "2001" or the magnetic boots of golden age
sci-fi.

And they helped with airflow, which is a *good thing* when you depend
on a handful of fans to supply you with fresh air to breathe.

Yeah, I hadn't thought of that aspect of the grid floor, but it
certainly would help with airflow. The airflow problem is one that
seldom gets mentioned in regards to microgravity. Theoretically, it
would be possible for you to suffocate in your sleep from the bubble of
exhaled CO2 surrounding you if there is no gas movement due to the lack
of the thermal upwelling of the cabin atmosphere, or the denser CO2
settling towards the floor.

Hmm, this poses the question if big open spaces like in Skylab are
better here than the cans on a string of ISS... In a large open space
you can probably get a good draft going with a quite simple setup,
while ISS needs lots of ducts to reach into every corner and module
(along with the noise air going through tight ducts tends to cause).


Jochem

--
"A designer knows he has arrived at perfection not when there is no
longer anything to add, but when there is no longer anything to take away."
- Antoine de Saint-Exupery

"Jochem Huhmann" wrote in message
...
Pat Flannery writes:

Jeff Findley wrote:
"
savings.
The grid floor work made it possible for the astronauts to have shoes
which could look them in place if need be...solid floors might have
needed Velcro like in "2001" or the magnetic boots of golden age
sci-fi.

And they helped with airflow, which is a *good thing* when you depend
on a handful of fans to supply you with fresh air to breathe.

Yeah, I hadn't thought of that aspect of the grid floor, but it
certainly would help with airflow. The airflow problem is one that
seldom gets mentioned in regards to microgravity. Theoretically, it
would be possible for you to suffocate in your sleep from the bubble of
exhaled CO2 surrounding you if there is no gas movement due to the lack
of the thermal upwelling of the cabin atmosphere, or the denser CO2
settling towards the floor.

Hmm, this poses the question if big open spaces like in Skylab are
better here than the cans on a string of ISS... In a large open space
you can probably get a good draft going with a quite simple setup,
while ISS needs lots of ducts to reach into every corner and module
(along with the noise air going through tight ducts tends to cause).

To a certain extent, probably.

One result other thing they've learned (I read it was a result of the Mir
decompression) is you're better off having hatches OPEN if a decompression
event occurs, until it can be located and isolated. Since basically it
gives the person more time to evacuate the module since there is a lot more
volume for the leak to draw from.



--
Greg Moore
Ask me about lily, an RPI based CMC.

"Greg D. Moore (Strider)" writes:

One result other thing they've learned (I read it was a result of the Mir
decompression) is you're better off having hatches OPEN if a decompression
event occurs, until it can be located and isolated. Since basically it
gives the person more time to evacuate the module since there is a lot more
volume for the leak to draw from.

I think this depends on which module is leaking. There's probably not
much doubt about keeping rarely used modules (garbage cans) sealed most
of the time. And surviving in a sealed module with no access to the
lifeboat or spacesuits buys you not much. In a rather large station with
lots of modules (like ISS) it's probably the wisest thing to keep only
those hatches closed that lead to very rarely used modules (which would
reduce the risk of overall decompression by a fixed amount if the risk
of getting leaky is the same in all modules).

Even then a station with large open spaces is probably better, because
ways are much shorter and you probably could easier locate the leak or
at least dash to the lifeboat in a matter of seconds. You get less inner
surface area though, so that you would end up with all walls covered
with racks and stuff and no way to fix the leak (if this an option at
all, but I think that a small hole in a bare wall could probably easily
be fixed even with a patch of duct tape, one atmosphere is not *that*
much). Large modules with a central column and bare walls are probably
the best here.

I do not care much for Ares I, but Ares V with 10 m payload diameter and
188 tonnes would allow to build some sensible space station ;-)

Jochem

--
"A designer knows he has arrived at perfection not when there is no
longer anything to add, but when there is no longer anything to take away."
- Antoine de Saint-Exupery

"Greg D. Moore \(Strider\)" wrote:

One result other thing they've learned (I read it was a result of the Mir
decompression) is you're better off having hatches OPEN if a decompression
event occurs, until it can be located and isolated. Since basically it
gives the person more time to evacuate the module since there is a lot more
volume for the leak to draw from.

We kept the hatches open because it prevented pressure differentials
from building up and made atmosphere circulation easier.

One of the first actions in the event of a casualty however was to
shut them on the latch.

D.
--
Touch-twice life. Eat. Drink. Laugh.

http://derekl1963.livejournal.com/

-Resolved: To be more temperate in my postings.
Oct 5th, 2004 JDL

Jochem Huhmann wrote:
Hmm, this poses the question if big open spaces like in Skylab are
better here than the cans on a string of ISS... In a large open space
you can probably get a good draft going with a quite simple setup,
while ISS needs lots of ducts to reach into every corner and module
(along with the noise air going through tight ducts tends to cause)

Ah yes, the Russian ISS fans:
http://www.newscientist.com/article/...s-hearing.html

Pat

Pat Flannery writes:

Jochem Huhmann wrote:
Hmm, this poses the question if big open spaces like in Skylab are
better here than the cans on a string of ISS... In a large open space
you can probably get a good draft going with a quite simple setup,
while ISS needs lots of ducts to reach into every corner and module
(along with the noise air going through tight ducts tends to cause)

Ah yes, the Russian ISS fans:
http://www.newscientist.com/article/...s-hearing.html

Yeah, I can very well imagine that noise is a major point of stress
there. Probably much like living in string of server rooms with
countless computer fans whirring all the time. I think I could stand
that for a week or so but not much longer. Whenever I see a video from
up there and listen to the audio I think "just like a long workday in
the machine room, just without going home afterwards".


Jochem

--
"A designer knows he has arrived at perfection not when there is no
longer anything to add, but when there is no longer anything to take away."
- Antoine de Saint-Exupery

Derek Lyons wrote:
We kept the hatches open because it prevented pressure differentials
from building up and made atmosphere circulation easier.

Did our sub's hatches have some way of equalizing pressure between two
compartments after being closed and sealed?
The Soviet ones apparently didn't, and that led to some getting stuck in
the closed position during accidents when pressure on the other side
increased due to fire or a overheated reactor, preventing the hatches
from being pushed open from the low pressure side even after they were
undogged.

Pat

Jochem Huhmann wrote:
Yeah, I can very well imagine that noise is a major point of stress
there. Probably much like living in string of server rooms with
countless computer fans whirring all the time. I think I could stand
that for a week or so but not much longer. Whenever I see a video from
up there and listen to the audio I think "just like a long workday in
the machine room, just without going home afterwards".

There's a distinct downside to it besides the hearing loss and annoyance
factor also... all that noise is going to cover up sounds of other
things that may be malfunctioning that you would want to shut down
immediately if you could hear them.
A astronaut on the Shuttle once described trying to sleep while the nose
RCS thrusters were firing as like trying to sleep while howitzers were
going off nearby.
When they came up with the posters for the movie "Alien", I don't think
they meant the reason no one could hear you scream in space was that the
air circulation fans on the Nostromo were so loud that they would give
the crew permanent hearing damage, even as the thing with the dill
pickle head was killing someone in the ceiling air duct five feet above
you.

Pat

Pat Flannery wrote:

Derek Lyons wrote:
We kept the hatches open because it prevented pressure differentials
from building up and made atmosphere circulation easier.

Did our sub's hatches have some way of equalizing pressure between two
compartments after being closed and sealed?

Yeah, but it wasn't very big.

D.
--
Touch-twice life. Eat. Drink. Laugh.

http://derekl1963.livejournal.com/

-Resolved: To be more temperate in my postings.
Oct 5th, 2004 JDL