Discussion -- Suppose we had evacuated ISS after Columbia?

Discussion -- Suppose we had evacuated ISS after Columbia?


I'm pondering the what-ifs of the option where the ISS is evacuated soon
after
Feb 1, 2003, probably at the point in April where the Soyuz lifetime limit
is reached.

I still assume launch of perhaps one Progress per year with propellant, as
needed, for Russian Segment attitude control system and reboosts. They
can all operate, I believe (verify or refute, please), under TsUP-Moscow
commanding.

What extra hazards for the ISS would that have engendered? What
resources on the ISS would have been saved?

What operational 'lessons' would not have been learned, and
so what? This assumes that after shuttles return to flight and the
station is again occupied, activities would have proceded in much
the same direction as they did in the real world -- but with a 3-person
crew, much faster regarding outfitting and assembly.

I can think of a number of things we HAVE learned by having the
crew on the station during this interval, but I can't think of any
that couldn't have waited a few years -- we're not yet applying
these real lessons to near-term challenges, as far as I can determine.

As a side note, I do wonder at the political and diplomatic hazards to
the partnership, as the delay stretches from months to years. That would
also be a major stresser on the teams training for the next flight. On the
other hand, would the teams NOT needed for continuous occupation
be available to assist in the challenges of planning for resumption of
occupation at some future point?

I don't see that any money is saved, either way -- except where some groups
in the US and in Russia get furloughed for a year or more.

You may see one angle to this discussion, and that has to do with an
alternative future in which the Russians had NOT become key partners
in the design. Loss of shuttle in such a case would have required a crew
evacuation (through a small bail-out capsule designed and built with all
the money that was saved by not having the Russians along and by
not having to haul all the hardware into an inefficient orbital
inclination).
What I wonder is: what would have been so bad about that?

Don't forget, episodic occupancy of space stations had been the norm
on Skylab, Salyut-4, 5, 6 and 7, and early Mir. What, aside from the time
saved in conserving/deconserving the systems, was the problem there
(one counter-example -- station breakdown and loss of control, which
actually happened, and was reversed eventually anyway).

Speculations and hard examples are solicited. Thanks!

Jim O
www.jamesoberg.com

Jim Oberg wrote:
I still assume launch of perhaps one Progress per year with propellant, as
needed, for Russian Segment attitude control system and reboosts. They
can all operate, I believe (verify or refute, please), under TsUP-Moscow
commanding.


Yes. but without crewmembers to tend to elektron, batteries, CDRA and
nobody to lsiten to for strange noises from CMGs, the station may have
had more breakdowns than it has had. And the 2.5 years since Columbia
have allowed the russians to advance the debugging of elektron quite a
bit, but making all sorts of tests. They may not have found a
permanently solution, but they've eliminated many possible solutions and
that is experience/time that was not wasted. Had the thing been offline
for 2.5 years, none of that debugging would have happened and when the
crew came back, they'd have to start the debugging 2.5 years late.

What extra hazards for the ISS would that have engendered? What
resources on the ISS would have been saved?

Since the ISS has essentially cost the USA nothing since Columbia,
nothing would have been saved, but more systems on the ISS may have
failed and restarting the ISS may have costed much more and it would
have taken more time to find all the things that had failed (such as EVA
suits for instance).


the same direction as they did in the real world -- but with a 3-person
crew, much faster regarding outfitting and assembly.

Why must faster ? It would have taken far more time once shuttle is
operational again to bring the station back to life, and it isn't a
given that the first shuttle could have left a crew on the ISS.

crew on the station during this interval, but I can't think of any
that couldn't have waited a few years -- we're not yet applying
these real lessons to near-term challenges, as far as I can determine.


While Russia hasn't learned much it didn't already know from MIR , NASA
has learned a lot in terms of procedures. Just consider how NASA had to
accept that it was possible for 2 men to put on EVA suits by themselves
and conduct an EVA withouth as most choreography that NASA had insisted
was so absolutely necessary ?


You may see one angle to this discussion, and that has to do with an
alternative future in which the Russians had NOT become key partners
in the design. Loss of shuttle in such a case would have required a crew
evacuation

You're assuming that a USA only station would have been complete enough
to have permanent crews by the time Columbia was destroyed. It isn't a
given that the plug could have been pulled alltogether before any US
pieces were launched.

Much has been said of how much russia's participation has costed the
USA. Little is said about the cost ovveruns at NASA which resulted in so
many modules being canned. In order for a USA only station to be
occupied, it would have needed propulsion module, hab module complete
with full ECLSS and toilet as well as galley, and more importantly, a
escape pod for emergency return to earth.

I can't find any credibility in the accusations that the current station
has costed more to the USA than if the USA had done it all by itself.

Remember that Russia was brought in because the USA project was costing
too much.

the money that was saved by not having the Russians along and by
not having to haul all the hardware into an inefficient orbital
inclination).

But you would have had to haul far more hardware and supplies. And even
if you saved a few Shuttle flights, that would have been peanuts at $400
million per flight compared to overall cost.

I realise that you have to write some sensationalistic story that makes
the USA look great, because that is what your employer expects of you.
So by all means, write about how much better it would have been, and how
the lack of russian particiaption would have saved so much money that
the USA would have had budgets to replace/upgrade the shuttle before the
columbia accident AND go to Mars. Write what americans want to read
instead of what they need to hear. Blame the russians for NASA's cost
overruns, that is what american readers like to read about. You might
also want to blame France, it is a popular target to blame for problems
in the USA these days.

"John Doe" wrote
Yes. but without crewmembers to tend to elektron, batteries, CDRA and
nobody to lsiten to for strange noises from CMGs, the station may have
had more breakdowns than it has had.

Well, consider reach example:

1. Elektron. It's turned off. Not needed. Can't fail.
2. Batteries. They do age, but they cycle much less frequently. Power
load without life support is a lot less.
3. CDRA. It's turned off. Not needed. Can't fail.
4. Strange noises from CMGs. There aren't any,
crew has been there for almost five years and hasn't heard
anything yet, so what's your point? Put station in GG attitude mode
and power down half the CMGs at a time.

Jim Oberg wrote:
1. Elektron. It's turned off. Not needed. Can't fail.

Its design has flaws which make it unreliable in the long term. Finding
that flaw is important. Turning it off and having it no crew for 2.5
years means that you're not debugging the unit and ruling out cause
after cause until you eventuially narrow down the problem. Shutting it
down delays having a reliable elektron by 2.5 years.

Just because they haven't found the real problem yet doesn't mean that
the work done so far has been worthless.

2. Batteries. They do age, but they cycle much less frequently. Power
load without life support is a lot less.

Prior to the station being inhabited, batteries were failing in Zarya.
You still need power for computers, guidance etc. And consider the
gimbals for the solar panels.

Remember the guidange outage where the station floated uncontrolled with
unaligned arrays not producing power, batteries running low and it was
the crew who used their eye and the windows in Zvezda to manually
command the arrays to turn to get enough sun to "reboot" the systems.

Had the station been unmanned, it would have had to be commanded into
thumble mode by ground, during which no progress or anything else having
the ability to dock. And then you assume that they could restart
attitude control and restabilise the station.

Consider the failure rate of the laptops, power supplies etc. While
most may not be critical on the USA segment, consider than an incoming
crew would arrive with totally useless commanding capability.

3. CDRA. It's turned off. Not needed. Can't fail.

Correct. and in this case, the USA doesn't seem to have spent much time
debugging its reliability problems.

4. Strange noises from CMGs. There aren't any,

During one failure of CMGs, noises were heard in the station and crew
alerted ground who then saw anomalous readings and commanded the
shutdown of the failed unit. This is why they suspect ball bearing
problems since those make noises.



It should seem really obvious to all by now that having redundant
systems from different sources is a real asset, not only on station, but
on ground and in vehicles. And with the USA having cutback its station
involvement to a bare minimum and widthdrawing the shuttle prematurely,
having the russians provide alternate support for station is an advantage.

If the russians weren't there, then the othert countries would not have
allowed Bush to widthdraw the shuttle at a specific date before a full
replacement in functionality was available. And they would not have
tolerated that the USA cancel its crew return vehicle, HAB etc etc.

"John Doe" wrote
Its design has flaws which make it unreliable in the long term. Finding
that flaw is important. Turning it off and having it no crew for 2.5
years means that you're not debugging the unit and ruling out cause
after cause until you eventuially narrow down the problem. Shutting it
down delays having a reliable elektron by 2.5 years.

Just because they haven't found the real problem yet doesn't mean that
the work done so far has been worthless.

Granted we have to find a better system than Elektron. This doesn't
mean band-aiding the current design when it's clear the current design
needs wholesale replacement. Learning how to make the current design
work is useless information, since the current system is going to be
retired soon anyway.

Jim Oberg wrote:
Granted we have to find a better system than Elektron. This doesn't
mean band-aiding the current design when it's clear the current design
needs wholesale replacement. Learning how to make the current design
work is useless information, since the current system is going to be
retired soon anyway.


retired soon ?????

Until you learn exactly what makes elektron fail, it is pointless to
think that shipping a new unit will magically solve your problems. It
may prove to be reliable for a while, but it will fail in the same ways
as the old elektron.

If they do manage to bring the old unit down for a post mortem, perhaps
the engineers on the ground might find the reason for it being
unreliable, but they may not since they can't reproduce 0g conditions on
the ground.

And it isn't a question of band-aiding the current design. It is a
question of finding out what works and what doesn, process of
elimination of possible causes and possible solutions. These are designs
which probably work flawlessly on the ground and really need to be
tested in long term use in 0g before the problems arise. This is why
leaving the unit off for 2,5 years would have been stupid since this is
the real research going on in the station.

The americans have 0 experience with O2 generators in space, so if/when
they do launch one, it will take 5 years before they know if it works
reliably or not. CDRA seemed to give them some reliability numbers
failry quickly though. (nort good).

The Zarya battery failures in 1998-9 were due to a particular bad batch
of units that had all been replaced by 2003.

Unmanned mode does not force commanding into tumble. The station
could be placed in a stable gravity-gradient attitude. The arrays don't even
need to actively track in such a low-load no-crew configuration.

The laptop failure rate is indeed alarming, but without a crew, so what --
they
are the only reason the laptops are needed.


"John Doe" wrote
2. Batteries. They do age, but they cycle much less frequently. Power
load without life support is a lot less.

Prior to the station being inhabited, batteries were failing in Zarya.
You still need power for computers, guidance etc. And consider the
gimbals for the solar panels.

Remember the guidange outage where the station floated uncontrolled with
unaligned arrays not producing power, batteries running low and it was
the crew who used their eye and the windows in Zvezda to manually
command the arrays to turn to get enough sun to "reboot" the systems.

Had the station been unmanned, it would have had to be commanded into
thumble mode by ground, during which no progress or anything else having
the ability to dock. And then you assume that they could restart
attitude control and restabilise the station.

Consider the failure rate of the laptops, power supplies etc. While
most may not be critical on the USA segment, consider than an incoming
crew would arrive with totally useless commanding capability.

On 2005-06-17, Jim Oberg wrote:

Unmanned mode does not force commanding into tumble. The station
could be placed in a stable gravity-gradient attitude. The arrays don't even
need to actively track in such a low-load no-crew configuration.

A thought - when Saluyt 7 was re-occupied by the first Mir crew, was it
stable or tumbling?

--
-Andrew Gray

Jim Oberg wrote:
Unmanned mode does not force commanding into tumble. The station
could be placed in a stable gravity-gradient attitude. The arrays don't even
need to actively track in such a low-load no-crew configuration.

But what happens when there is a guidance system failure as has happened
before ? If they can't recover, they must put the station in thumble
mode so that arrays get ~some~ sunshine during each orbit.

And there are serious electrical loads when there are no crews. You need
need cooling/heating, some ventilation, all the sensors. So your load
diminishes because you doN't have Elektron and Vozdhuk running, and
hopefully, the condensing units won't fill up during the years of
unmanned since there are no humans breathing humidity, but the cooling
is still needed.

And you still need electricity to have the arrays track the sun, GPS
units, Comms, cameras. Etc.

"John Doe" wrote
JimO: 4. Strange noises from CMGs. There aren't any,

During one failure of CMGs, noises were heard in the station and crew
alerted ground who then saw anomalous readings and commanded the
shutdown of the failed unit. This is why they suspect ball bearing
problems since those make noises.

Hmmm, I don't recall this. I know the crew had heard 'strange noises', but
I didn't think any were associated with CMG problems that the crew
could monitor on displays of data that the ground could not see.

If you can be more specific on date I can check the detailed records
available in my archives.