What if MIR hadnt been de orbited?

"Henry Spencer" wrote in message
...
Note also that von Braun's station design almost certainly would not have
worked, because it spins too fast. The limits to human tolerance in this
area are not terribly well known -- the exact situation is impossible to
simulate on Earth -- but rotating-room experiments suggest that around
5rpm is tops even for selected crews, and 2rpm or less is preferable.
A 1G 2rpm station is nearly half a kilometer across.

Just happened to catch a program on new skyscraper construction on PBS.
Studies for a Hong Kong building (I believe being designed by Leslie
Robertson, the designer of the WTC) included studies on just how much
shaking could be tolerated by people engaged in tasks requiring eye-hand
coordination.

OK, This appears to be a serious answer to my question.

Pat Flannery wrote:

Michael Walsh wrote:

This is not at all a convincing argument as you make the rather broad
claim that what you say is true without bothering to state any kind of
a case



When Mir was designed it was intended that the Buran shuttle would be
sent to it with new modules, and the older modules would be returned to
earth via the Buran; after Buran was canceled their was no way to
replace the modules other than cut them free of the station before a new
one was docked; they didn't have money for any more modules (the ones
they used went up way behind schedule because of funding constraints) so
it effectively became a fixed configuration.

Let me be clear that I believe that if you need to replace all or most of
the MIR modules it would cost more to try to swap out old structure than
to launch and assemble a new station in orbit. Perhaps someone has some
concept to do this, but everything I have read about MIR would indicate that

this is not very practical as the modules are securely tied together. After
all
these years some of the connection points might be effectively
"welded" together.

It would have taken some work to disengage the four front modules from
Mir's power system; but they could have been replaced if desired by new
ones. But the station took so much longer to complete than had been
planned that the core module and rear-mounted Kvant module were wearing
out by the time it was done; as evidenced by the serious glycol coolant
leak caused by corrosion of the plumbing.

Pat

The issue I wished to discuss is whether or not MIR could have been
economically refurbished for long term operation using the structural
modules with replacement of internal systems.

This is, obviously, a hypothetical discussion and is appropriately in
sci.space.history as we are not going to dig MIR parts out of the
ocean and relaunch them.

I wish to discuss the subject seriously. I am a retired engineer sitting
in front of my computer at home. I have read quite a bit about the
pros and cons of MIR refurbishment in these newsgroups. I don't
have access to any industry or government reports that address this
subject so I can't give any detailed analysis. Perhaps someone can
provide information from some good source (preferably on-line) but
so far I have not seen any.

Mike Walsh

On Sun, 15 Feb 2004 23:07:02 +0000, Jonathan Silverlight
wrote:

In message NQRXb.518149$X%5.163776@pd7tw2no, Dave Michelson
writes
RDG wrote:
... Quite a number of engineers involved in building the ISS felt
that a cicular, Von Braun type station, always rotating and complete
the time of habitation was the way to go. This is what we saw in
"2001", and the vision remains.

Minor nit: That wasn't quite what we saw in 2001. The station was habitable,
but it was also still under construction. Moreover, major construction was
taking place while the structure was rotating. (IIRC, Clarke later admitted
that this was one of the few major technical flaws in the film.)

As well as the Chesley Bonestell moonscapes, the lack of radiators on
Discovery, the astronaut holding his breath, and the jump from gibbous
to crescent Earth, And a moonbus going from Clavius to Tycho would
either use wheels or a ballistic trajectory. It wouldn't fly a few
hundred feet up.
The drink falling back down the straw in microgravity, and some very odd
shadows on a rotating astronaut (that last according to Brian Ford)
probably count as minor technical flaws.
2001 is a beautiful and remarkable film, but the idea that it's
technically flawless is looking a bit thin by now.

It wasn't technically flawless at the time. For example, the
spaceship model bows upward because they shot those scenes with it
upside down and it was long enough and flexible enough that gravity
made it bow. You could see it if you looked and we all knew to look.

Mary

--
Mary Shafer Retired aerospace research engineer

On Sun, 15 Feb 2004 17:29:41 -0600, Pat Flannery
wrote:

Jonathan Silverlight wrote:

2001 is a beautiful and remarkable film, but the idea that it's
technically flawless is looking a bit thin by now.

And once the monkeys stop fighting, it moves at the pace of molasses on
a December morning.

What time of year was the Great Molasses Flood in Boston? That
molasses moved fast enough to kill at least one person.

Mary

--
Mary Shafer Retired aerospace research engineer

"Mary Shafer" wrote in message
...
On Sun, 15 Feb 2004 17:29:41 -0600, Pat Flannery
wrote:

Jonathan Silverlight wrote:

2001 is a beautiful and remarkable film, but the idea that it's
technically flawless is looking a bit thin by now.

And once the monkeys stop fighting, it moves at the pace of molasses on
a December morning.

What time of year was the Great Molasses Flood in Boston? That
molasses moved fast enough to kill at least one person.

January.

http://www.mv.com/ipusers/arcade/molasses.htm

So as slow as molasses in January ain't quite slow enough.



Mary

--
Mary Shafer Retired aerospace research engineer

In article ,
Mary Shafer writes:
On Sun, 15 Feb 2004 17:29:41 -0600, Pat Flannery
wrote:

Jonathan Silverlight wrote:

2001 is a beautiful and remarkable film, but the idea that it's
technically flawless is looking a bit thin by now.

And once the monkeys stop fighting, it moves at the pace of molasses on
a December morning.

What time of year was the Great Molasses Flood in Boston? That
molasses moved fast enough to kill at least one person.

February, I think, or January. Mid-Winter, anyway.
Killed more than one person. People, Horses, & most of several city
blocks were washed under by the sugary Tsunami.

Slow as Moalsses running uphill in Fenruary - Hah!

--
Pete Stickney
A strong conviction that something must be done is the parent of many
bad measures. -- Daniel Webster

Henry Spencer wrote:
Note also that von Braun's station design almost certainly would
not have worked, because it spins too fast. The limits to human
tolerance in this area are not terribly well known -- the exact
situation is impossible to simulate on Earth -- but rotating-room
experiments suggest that around 5rpm is tops even for selected
crews, and 2rpm or less is preferable. A 1G 2rpm station is nearly
half a kilometer across.

I'd be surprised if people couldn't adapt. Especially military pilot
types, who are accustomed to lots of G forces in random directions.
Didn't they test the Mercury astronauts by tumbling them randomly?
And didn't some Skylab astronauts jog in circles around the perimeter
of Skylab, which should have had the same effect as if they were
standing still and Skylab was rapidly rotating?
--
Keith F. Lynch - http://keithlynch.net/
Please see http://keithlynch.net/email.html before emailing me.

Michael Walsh wrote:

Let me be clear that I believe that if you need to replace all or most of
the MIR modules it would cost more to try to swap out old structure than
to launch and assemble a new station in orbit. Perhaps someone has some
concept to do this, but everything I have read about MIR would indicate that

this is not very practical as the modules are securely tied together. After
all
these years some of the connection points might be effectively
"welded" together.

The gaskets could indeed be a problem; what might happen is the same
sort of thing that occurred when the Progress freighter shed its front
gasket a few years back; you might tear part or all of the gasket off of
the Mir docking port as the module detached.



The issue I wished to discuss is whether or not MIR could have been
economically refurbished for long term operation using the structural
modules with replacement of internal systems.

The internal systems were difficult to get at for repair and
replacement; some may have been riveted directly to the walls, or
attached in other non-removable ways. They had a hell of a time getting
a panel off to search for the glycol leak according to the book
"Dragonfly". And the glycol cooling system was a big problem in regards
to any major overhaul of the station on-orbit; the plumbing pierces the
pressure hull of the modules to reach the externally mounted radiator
panels, so that any major work on it is going to require that the
pressure integrity of the module not be compromised in the process;
they never did find the leak in the Spektr module caused by the
Progress collision, although it was suspected to be at the base of one
of the solar arrays.
All-in-all, I'd say it would be far easier to simply start rebuilding it
component by component (this works right up till you get to the Mir core
module) rather than trying to refurbish it; the Soviets intended to
replace it with Mir II at some future date, but the funding dried up.
What really screwed the whole Mir program up was the fact that the
assembly of all the modules was suppose to proceed rather quickly once
the core module and Kvant had docked, but funding constraints meant the
four additional modules were stretched out over a period of years (if
they had been smart they wouldn't have started launching it until all
the parts were completed; but Soviet politics and prestige being what
they were they needed something to follow Salyut 7 in fairly close
order), and once it was all assembled its age was really starting to
show in regards to its systems; unfortunately, the ISS shows every sign
of running into the same sort of problem, especially with the grounding
of the Shuttle. We are now planning for what? Completion around the end
of the decade? The original completion date was supposed to be December
of last year.

Pat

Mary Shafer wrote:


It wasn't technically flawless at the time. For example, the
spaceship model bows upward because they shot those scenes with it
upside down and it was long enough and flexible enough that gravity
made it bow. You could see it if you looked and we all knew to look.


Then there were those two fast spinning asteroids that zoom be the ship
as it is in the asteroid belt...I can see one... but _two_ that close
together? Discovery would have been toast.

Pat

In message , Mary Shafer
writes
On Sun, 15 Feb 2004 23:07:02 +0000, Jonathan Silverlight
wrote:

In message NQRXb.518149$X%5.163776@pd7tw2no, Dave Michelson
writes
RDG wrote:

Minor nit: That wasn't quite what we saw in 2001. The station was
habitable,
but it was also still under construction. Moreover, major construction was
taking place while the structure was rotating. (IIRC, Clarke later admitted
that this was one of the few major technical flaws in the film.)

As well as the Chesley Bonestell moonscapes, the lack of radiators on
Discovery, the astronaut holding his breath, and the jump from gibbous
to crescent Earth, And a moonbus going from Clavius to Tycho would
either use wheels or a ballistic trajectory. It wouldn't fly a few
hundred feet up.
The drink falling back down the straw in microgravity, and some very odd
shadows on a rotating astronaut (that last according to Brian Ford)
probably count as minor technical flaws.
2001 is a beautiful and remarkable film, but the idea that it's
technically flawless is looking a bit thin by now.

It wasn't technically flawless at the time. For example, the
spaceship model bows upward because they shot those scenes with it
upside down and it was long enough and flexible enough that gravity
made it bow. You could see it if you looked and we all knew to look.

Ah, but you're a professional! Reading that, I wonder why they didn't
shoot from underneath. Or was 2001 the film that showed them they should
do so? It's common practice now.
--
Save the Hubble Space Telescope!
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