NY Times, Computer Flaw Could Imperil Space Station

Danny Deger wrote:
Is it possible the new power system fried the Russian computers and they
need to be replaced?


Highly doubtful. There is a power transfer module on the Z1 truss (on
top of Unity). As I recall (but faded memory), this also converts
voltages from US to Russian segment voltage levels.

Secondly, the media reports are not trustable enough to base our
judgement on the word "reboot". This may mean that the hardware is
fried, it could mean that the hardware works fine but the OS won't load
(disk corruption etc), or it may mean that the computers are up and
running, but the application program that does the attitude control
won't start (or starts up but does nothing).

Consider this: what really changes is that on both sides of the station,
they changed the attitude control parameters now that the mass of the
station is higher with different centre of gravity. Not sure if this was
a new version of software applied, or whether the crews added more
parameters to describe the new station config, or whether that config
had been loaded a long time ago and was just activated.

We have way too little information to really know what really happened.
(and I really wish I lightning hadn't struck in the backyard so I could
listen to NASA TV because that may have yielded some information.
(Although the russian loop would have provided more info).

"JF Mezei" wrote in message
...
Jim Oberg wrote:
The Progress engines are controlled by the computers that had crashed.

But can't Progress be controlled directly by the ground, bypassing the
station computers ?

Gerstenmeier referred to this in his briefing this afternoon, and it's true
that commands can be sent directly for firings, or programmed firings be
uploaded for timed firings -- but only during Russian Ground Segment
AOS periods. Gerst suggested that such heavy-handed firings could be
developed to desaturate the CMGs when needed, and it would be
a 'rough and ready' kind of operation but might be feasible. But the AOS
requirement would be a real pain to try to operate through.

When I write reboot I mean r-e-b-o-o-t -- dead start with external
mechanical/electrical instigation. The computers were rebooted this
morning, one pair came up synced and ran for seven minutes
before freezing up, the other four powered up but never
flagged 'READY' and were later turned off. Something is VERY
sick within their innards or with their nutrition....

"John Doe" wrote
Secondly, the media reports are not trustable enough to base our judgement
on the word "reboot".

Jim Oberg wrote:
When I write reboot I mean r-e-b-o-o-t --


But how far into the reboot sequence does it go before problems happen ?

And when it crashes, is it the application which crashes or is it the OS ?

Will HP send a support person to the station to fix this problem ? (as I
recall, HP provided the computers for the russian segment.) (Of course,
that was the real HP, before Carly destroyed the original company).

And during those 7 minutes where it supposedly ran, was it fully
functional with interactions with the USA computers ?

Any change that it is the USA computers feeding the russian ones out of
bound values with the russian side software having alwasy assumed the
USA computers wouldn't send bad data ?

In a recent EVA, didn't they install some external ethernet cable ? What
was this cable for and is it connected to those computers ? Seems to me
that an outdoors ethernet cable might pick up a lot of noise and spikes.

On Jun 14, 2:00 pm, "Jim Oberg" wrote:
This morning a pair of computers was brought up, and it ran seven minutes
before crashing again.

"Jim Oberg" wrote in message

...





"John Doe" wrote
Those media articles you pointed to are so full of exagerations.
Is there not a Progress docked ? And they also have a Soyuz that can, in
a bind, perform station orientation. They did it a few times on Mir.

The Progress engines are controlled by the computers that had crashed.

The Soyuz was able to steer the Mir in emergencies, briefly -- but
check your notes, ISS is much, MUCH more massive than Mir.

Some signs of recovery this morning -- question is, how enduring will it
be?- Hide quoted text -

- Show quoted text -

It is 6:30 pm Central time. The NASA briefing makes it sound like the
computers are not fried but just unhappy with the new power. And the
good news is it will not be a big problem to go back to the old power
supply. Hopefully the fix will be this simple.

Danny Deger

wrote:
It is 6:30 pm Central time. The NASA briefing makes it sound like the
computers are not fried but just unhappy with the new power. And the
good news is it will not be a big problem to go back to the old power
supply. Hopefully the fix will be this simple.


Ex-squeeze me ?

If those new solar panels provided "strange" power then all of the
station would feel the ill effects of "strange" power.

Surely they have some voltmeter on the station and can measure the power
at the plug where those computers are connected ?

Surely the power converter between Z1 (us segment power) and the russian
segment would filter out anomalies in the USA power ? (Or at least
report on voltage levels on both sides and see some anomalies ?)

I find it extremely odd that this would be a power supply issue and this
is more likely parametrisation problems with the new mass distribution
of the station.

Unless of course, astronauts screwed up some grounding and Z1 is no
longer properly grounded.

Real spacemen don't 'hope', they dig for truth.

And the inconvenient truth is that the computer troubles began BEFORE the S3
power was fed.


wrote
It is 6:30 pm Central time. The NASA briefing makes it sound like the
computers are not fried but just unhappy with the new power. And the
good news is it will not be a big problem to go back to the old power
supply. Hopefully the fix will be this simple.

On Jun 14, 8:25 pm, "Jim Oberg" wrote:
Real spacemen don't 'hope', they dig for truth.

And the inconvenient truth is that the computer troubles began BEFORE the S3
power was fed.

wrote


This is very interesting news. Could it be NASA is not telling us
all? Is it possible NASA would tell a "non-truth"? Surely not :-)

Is it possible that the agency that lied about my behavior in 1999 to
have me detained against my will is once again lying?

We will have to wait and see.

Danny Deger

If they can't tell them to give me a call, it's as simple as picking two or
three of the right attitudes. That meet the important constraints the best.

I would think that they have enough control using the solar arrays. They
just added some real big ones. As the altitude drops, the Station
encounters more drag from the atmosphere. The solar arrays are like sails,
an old square rigger that can only sail downwind (downward). Just set the
sails correctly and attitude will be adjusted...
Bad attitude is no reason to abandon ship...

"Jim Oberg"...
You're right, some new CMG control algorithms have been flight tested --
and I should call the company that sent out the boastful press release
a few months ago to see if they think they can do ALL required attitude
control...
It could happen...

"Craig Fink"...
I believe NASA already has the software or at least the algorithms to do
attitude maneuvers on the CMGs alone. If this capability is up and
running,
I would think they could desaturate the CMGs by maneuvering between two
or more attitudes keeping them reasonably desaturated.

On Jun 14, 12:36 am, John Doe wrote:
If they leave the station, it means that its attitude control has become
uncontrolled. And it probably means that later on, station might be
thumbling and that means that docking to station would become nearly
impossible.

Which (off topic) is one of the things which has always bugged me
about the movie 2001. All HAL needed to do was bleed some energy off
of the carousel which would cause Discovery to tumble end over end.
Bowman would have had a really tough job getting in to the emergency
airlock.