What is the lowest cost solution for environmental control systems for space stations?

"Derek Lyons" wrote in message
...

The simple fact is, the Russian segments of ISS are near copies of MIR
equipment, and contain many of the same flaws and problems. (Witness
the endless problems with their life support equipment.) Where is
their experience? Why is it not in evidence?

Their experience is evident. They're handing life support on ISS just as
they had on Mir. What's lacking is any real improvement in the reliability
of the equipment. The Russians may not see this as necessary, since their
experience shows that they can fix things in orbit with spare parts sent up
on Progress.

The desire for improvement drops as people accept the hardware as "good
enough". The Russians appear much more willing to accept equipment as "good
enough" that Americans would reject as "failure prone".

Jeff
--
Remove icky phrase from email address to get a valid address.

Jeff Findley wrote:
The desire for improvement drops as people accept the hardware as "good
enough". The Russians appear much more willing to accept equipment as "good
enough" that Americans would reject as "failure prone".

While these arguments appear acceptable on the surface, I am not really sure
that they are so valid.

Until they find out exactly what causes bubbles to appear and clog the
Elektron machine, there is really nothing much they can do to fix it. Remember
that these problems do not happen on earth due to gravity, so the only way to
test and debug the machine is in space.

Now, your message made it appear like the russians were happy with the
problems they have since they's so mar managed to fix. However, consider the
problems on the USA segment. CDRA for example. Has it been fixed to become a
rock-solid reliable bet-you-life piece of equipment, or is it still runned
only from time to time because they know it will fail if runned for too long ?
How come they haven't fixed it yet ? How come its problems weren't foreseen
during the extensive testing that had been done on earth prior to launch ?

The answer is probably the same as for the russians: there are thing you can't
test and debug on earth. And this is why the ISS is a critical piece of
hardware and experience required before you can think about building a ship to
mars. Work on the ISS until they get it right, then they can think about Mars.

"Derek Lyons" wrote in message
...
"Mike Walsh" wrote:


"Derek Lyons" wrote in message
...
"Mike Walsh" wrote:

snipped handwaving and point evading nonsense.

Yes, my posting of things that the Russians are doing right now that
demonstrates some of their current capabilities in space. For some
reason you regard that as point evading nonsense.

Yes, it is. The point is the things they are doing wrong and having
problems with, and you won't adress them.

Where can I find out the things that they are doing wrong and are
having problems with?


The simple fact is, the Russian segments of ISS are near copies of MIR
equipment, and contain many of the same flaws and problems. (Witness
the endless problems with their life support equipment.) Where is
their experience? Why is it not in evidence?

Well, the MIR was an operating space station for over ten years. The
Russians certainly have shown experience in coping with these problems.



I would also say that a lot of the problems of the Russians have
come about because of bad management and a lack of
coordination between groups.

Which would not exist if they had the experience claimed.

Experience eliminates bad management? Not in my experience.

Experienced management leads to a reduction of mistakes.


Not necessarily true, particularly in government agencies.
Sometimes the same mistakes just get made over and over.

I am a bit curious about what the Russians are doing on the ISS and
whether or not some of the same problems are still there. Also,
what clout does NASA have to make certain the Russians don't
compromise safety of the station.

For instance:

Progress is used to supply the ISS. Whatever happened with
the Russian plans for manual docking of Progress that resulted in
the MIR problems and collision? Have they gone back to the
older procedures and kept using them or do they have something
newer that is now being used?

I believe that the same oxygen generators that caused the fire on
the MIR are still being used on the ISS (I believe I read that
somewhere.) Has anything been done to better determine
just how the failure occurred and are procedures in place
to prevent the problem from occurring in the future?

I am interested in getting information about the problems on
the ISS and how much of them are caused by Russian
equipment and operations as opposed to U.S.
equipment/operations.

I note that you expect me to take on face value anything
you post and I have read enough of your posts to believe
that you have good sources of knowledge about the ISS.

Do you have the information because you have been in
a working position on the ISS?

If not, do you have sources of information on ISS problems
for which you can supply references?

Mike Walsh

"John Doe" wrote in message ...
Jeff Findley wrote:
The desire for improvement drops as people accept the hardware as "good
enough". The Russians appear much more willing to accept equipment as
"good
enough" that Americans would reject as "failure prone".

While these arguments appear acceptable on the surface, I am not really
sure
that they are so valid.

Until they find out exactly what causes bubbles to appear and clog the
Elektron machine, there is really nothing much they can do to fix it.
Remember
that these problems do not happen on earth due to gravity, so the only way
to
test and debug the machine is in space.

Now, your message made it appear like the russians were happy with the
problems they have since they's so mar managed to fix. However, consider
the
problems on the USA segment. CDRA for example. Has it been fixed to become
a
rock-solid reliable bet-you-life piece of equipment, or is it still runned
only from time to time because they know it will fail if runned for too
long ?
How come they haven't fixed it yet ? How come its problems weren't
foreseen
during the extensive testing that had been done on earth prior to launch ?

The answer is probably the same as for the russians: there are thing you
can't
test and debug on earth. And this is why the ISS is a critical piece of
hardware and experience required before you can think about building a
ship to
mars. Work on the ISS until they get it right, then they can think about
Mars.

Are there some sources that summarize the problems occurring on the ISS?

I don't question that the Russians are having problems on their side, but
are their problems any worse than those on the U.S. side?

Mike Walsh

Mike Walsh wrote:
Where can I find out the things that they are doing wrong and are
having problems with?

The Elektron oxygen generator has required multiple rounds of maintenance
since it was installed in ISS.

Well, the MIR was an operating space station for over ten years. The
Russians certainly have shown experience in coping with these problems.

The original poster point was that since the Russians had learned to cppe with
the problems, they had less incentive to get them fixed once and for all.

Progress is used to supply the ISS. Whatever happened with
the Russian plans for manual docking of Progress that resulted in
the MIR problems and collision?

Toru is still available. The big problem on Mir is that the crew members had
not received proper training and simulator time, so his training was with the
real item. Also, because the Progress' radar was interfering, he was told to
shut it down, which removed valuable information on the progress's speed,
attitude, position/distance.

I believe that the same oxygen generators that caused the fire on
the MIR are still being used on the ISS

They now have expiry dates. And crew members on ISS had exhibited reluctance
to use candles that were NEAR the date (but not expired yet).

Mike Walsh wrote:
I don't question that the Russians are having problems on their side, but
are their problems any worse than those on the U.S. side?

It is hard to compare the problems of the russian oxygen generator to an
american one since there is no US O2 generator.

The russian CO2 scrubber seems to work more reliably than its US counterpart
(CRDA). It is used more heavily, and it is not without its need for regular maintenance.

Russians don't have CMGs so the failure of the US ones can't be compared.

The american threadmill had caused plenty of problems right from the start. To
me, this is definitely a flawed design (or rather an "over design"). This is a
device which should have been testable fully in 1 G.

One issue that also differentiates the Russian from US segment. The Russian
segment is essentially stable, without any contruction, additions or plans for
additions. The US segment is still under construction, even though
construction has stopped temporarily due to Columbia.

So glitches prior to shuttle stand down were, to a large extent (except CDRA
and threadmill) breaking-in and initial debugging stuff. Hard disk drive
failures are such an example (NASA knew they needed replacing but had not had
the time to get the solid state drives ready prior to launch, so those were
brought in later).

Look at the russian Orlan suits. Twice, they failed into the EVA. It seems to
me that twice, the crews were told to go through the suits and test them
extensively prior to the EVA, but it was something they did on the day of EVA
which produced the kink into the suit and subsequently resulted in the EVA
being cut short.

Perhaps the procedures need to be updated ? Perhaps training on how to
test/don suits needs to be improved ? But do you see this as a "systematic
failure" or just some bad luck glitch ? Or perhaps it is this particular crew
which was not trained properly. Or perhaps the procedures for 2 man crew cut
some corners versus the nominal 3 man crew procedures, and thus some testing
was skipped ? I don't know.

The failure of the second CMG is totally expected. NASA has estimates on
failure rates on outdoor devices (MDMS, RPCMs), so the failure of an RPCM
outdoors is not unexpected. This is why Canada is providing the "hand" that
will allow the arm to replace electronic components from outdoor devices.
(thus reducing need for EVA). They've also have a couple RPCM fail indoors.
But since they have spares on board, it isn't the end of the world.

Overall, I'd say that since contruction stopped, the station seems to have
performed quite well.

"John Doe" wrote in message ...
Mike Walsh wrote:
Where can I find out the things that they are doing wrong and are
having problems with?

The Elektron oxygen generator has required multiple rounds of maintenance
since it was installed in ISS.

Well, the MIR was an operating space station for over ten years. The
Russians certainly have shown experience in coping with these problems.

The original poster point was that since the Russians had learned to cppe
with
the problems, they had less incentive to get them fixed once and for all.

Progress is used to supply the ISS. Whatever happened with
the Russian plans for manual docking of Progress that resulted in
the MIR problems and collision?

Toru is still available. The big problem on Mir is that the crew members
had
not received proper training and simulator time, so his training was with
the
real item. Also, because the Progress' radar was interfering, he was told
to
shut it down, which removed valuable information on the progress's speed,
attitude, position/distance.

I believe that the same oxygen generators that caused the fire on
the MIR are still being used on the ISS

They now have expiry dates. And crew members on ISS had exhibited
reluctance
to use candles that were NEAR the date (but not expired yet).

Thank you for your response.

Do you have any sources or suggestions for information
(preferably on line) that summarizes ISS problems.

I have not done a throrough on-line search so an acceptable
response would be for me to do my homework first.
I did a fair amount of searching on MIR problems (a while back)
but not on the ISS.

Mike Walsh

Mike Walsh wrote:
Do you have any sources or suggestions for information
(preferably on line) that summarizes ISS problems.

Not quite sure. I've just listened to many hours of ISS audio over the last
couple of years, as well as reading this newsgroup for interesting tidbits now
and then.

Oh, others issues they have had recently was battery management, (some
batteries that were dying (no longer receheargable). Recall that they use
lost of batteries fof all sorts of protable gizmos on the station. And one of
the battry problems was on a laptop.

Oh, others issues they have had recently was battery management, (some
batteries that were dying (no longer rechargable). Recall that they use
lost of batteries fof all sorts of portable gizmos on the station. And one of
the battery problems was on a laptop.

Yup, that's what happens to batteries after a few years here on earth
too.

Of course it is easier to just pop over and buy a new one here.

I guess the other solution (at least in the laptop case), which is to
forget about the batteries and just plug it in, would probably also
work on the station.

Jim Kingdon wrote:
Yup, that's what happens to batteries after a few years here on earth
too.

The problem is one of crew time. They can't just discard a battery they
suspect of being in progress of failing.

In the case of the failed laptop battery, they ran tests, noticed the extreme
heat generated by laptop (enough to fear laptop failure) and then decided to
move the battery to another laptop. However, each step required coordination
with the ground so that they can keep track of which battery is in which
laptop, and which laptop has become "tied to the ground" due to lack of battery.

The problem with ISS, and this seems more evident on the US segment which has
mode "gadgets", is that if they don't micro manage the inventory and location
of equipment, it won't be long that nobody will know where everything is.
Consider that after a crew change, it is often the ground that remembers where
the former crew stowed item ABC,

In a lab on earth where employees work there for years, this is less of a
problem. But on the station with a 100% crew change every 4-6 months, this is
a problem, and hence why "ground" micromanages all these things. If when ISS
crew size in increased, it will be interesting to see of they continue with
100% crew changes, or of they stagger each cremember's mission to ensure an
overlap of a few months whcih allows the new crew member to "learn" from the
older ones over a much longer period of time than just a couple of days as is
the case now.

For instance, in the case of Elektron or the threadmill, which have both
required heavyt duty maintenance by multiple crews, it would be interesting to
know if lack of first hand knowledge transfer betwene crews would have
resulted in subsequent maintenance/repairs taking longer because the new crew
member didn't fully benefit from previous crew's experiences.

It is one thing to read or "hear" about a previos crew's work on a unit, but
if you can actually be with that crew member on site and have him show you
what he did, where the vibration comes from, where the noise comes from etc,
then I wonder if that would have significant value to help the new crew
continue to debug/maintain/repair the station.