ECO Problem "not generic"?

http://www.spaceflightnow.com/shuttl...4/050723count/

Engineers said earlier this week that even subtle grounding
problems could result in electromagnetic interference that
might affect the signals to and from the ECO sensors. But
again, engineers were not able to duplicate the failure
signature and the problem remains an unexplained anomaly.
...
If a problem shows up during fueling with sensor No. 4, engineers
will have high confidence the problem is somewhere in the wiring
between the point sensor box and the sensor itself, and not a
generic problem that could affect the other three sensors.

I have some difficulties to understand the logic of the last sentence.
As the failure went up only in cryo cold conditions it could well
be due to thermal contraction of some parts somewhere. Thats more
or less a mechanical problem affecting the electrical system of
at least one sensor system now. But if the Shuttle launches the
extraordinary vibrations could well have a similar effect like the
thermal contraction. It could affect the other 3 sensor systems
wiring/grounding even more than the thermal contraction of the one
system we know from. So I see no evidence that the problem is
not generic to the whole fleet now.


## CrossPoint v3.12d R ##

It is a Fascist Conspiracy on the far Right to kill all space exploration.

That is why the US Air Force is seeking "High Frontier" authorization -
in order to block all space flights with offensive space weapons
controlled by the US military.

I'm telling you folks, we're looking at a rebirth of something worse
than NAZI Germany in the "New Roman Empire" of the USA under Republican
Party Rule.

Get a clue - didn't any of you watch "X-FILES" or "Millennium"?

Thanks,

Rick



wrote:
http://www.spaceflightnow.com/shuttl...4/050723count/

Engineers said earlier this week that even subtle grounding
problems could result in electromagnetic interference that
might affect the signals to and from the ECO sensors. But
again, engineers were not able to duplicate the failure
signature and the problem remains an unexplained anomaly.
...
If a problem shows up during fueling with sensor No. 4, engineers
will have high confidence the problem is somewhere in the wiring
between the point sensor box and the sensor itself, and not a
generic problem that could affect the other three sensors.

I have some difficulties to understand the logic of the last sentence.
As the failure went up only in cryo cold conditions it could well
be due to thermal contraction of some parts somewhere. Thats more
or less a mechanical problem affecting the electrical system of
at least one sensor system now. But if the Shuttle launches the
extraordinary vibrations could well have a similar effect like the
thermal contraction. It could affect the other 3 sensor systems
wiring/grounding even more than the thermal contraction of the one
system we know from. So I see no evidence that the problem is
not generic to the whole fleet now.


## CrossPoint v3.12d R ##

wrote in message
...


http://www.spaceflightnow.com/shuttl...4/050723count/

Engineers said earlier this week that even subtle grounding
problems could result in electromagnetic interference that
might affect the signals to and from the ECO sensors. But
again, engineers were not able to duplicate the failure
signature and the problem remains an unexplained anomaly.
...
If a problem shows up during fuelling with sensor No. 4, engineers
will have high confidence the problem is somewhere in the wiring
between the point sensor box and the sensor itself, and not a
generic problem that could affect the other three sensors.

I have some difficulties to understand the logic of the last sentence.
As the failure went up only in cryo cold conditions it could well
be due to thermal contraction of some parts somewhere. That's more
or less a mechanical problem affecting the electrical system of
at least one sensor system now. But if the Shuttle launches the
extraordinary vibrations could well have a similar effect like the
thermal contraction. It could affect the other 3 sensor systems
wiring/grounding even more than the thermal contraction of the one
system we know from. So I see no evidence that the problem is
not generic to the whole fleet now.


## CrossPoint v3.12d R ##
This is a difficult one, and its one of the times when you do need past
experience to make a call. Of course, you want to find the cause, but if you
have examined everything and cannot find it, what do you do? Only
substitution can find the culprit, and how many times can you safely tank
and detank the fuel anyway?
Ideally, I suppose, you would change the tank (again), but I'd havethought,
three working sensors offers a better redundancy than other parts in the
Shuttle system.

Someone will have to make a difficult decision if the fault shows up.

If RF pick up can screw the system, how come we have not heard about it
before?

Brian

--
Brian Gaff....Note, this account does not accept Bcc: email.
graphics are great, but the blind can't hear them
Email:
__________________________________________________ __________________________________________________ __________

Brian Gaff wrote:

If RF pick up can screw the system, how come we have not heard about it
before?

As of yesterday morning's news conference, NASA had ruled out the RF
explanation completely -- gone, vanished, never happened. All blame had
been placed on improper grounding.

Challenger's Ghost

Mike Hunt wrote:

subtext deleted

"I'm not an NSA agent, I PROMISE!"

Mike said Bruce was a "goof guy" err "good guy"

He told me I could say this publicly without recourse from our
Elephantine Fascist current system of governing fools..

Cheney has enough money to buy a satellite launch, and after that
happens there will be no freedom on Earth in any way. Chen3y has been
buying Bush's assassination for 7 years.

The space shuttle will launch successfooly, but what is its cargo? An
assassination satellite?

Thanks,

Rick



Bruce Palmer wrote:
wrote:

http://www.spaceflightnow.com/shuttl...4/050723count/

I have some difficulties to understand the logic of the last sentence.
As the failure went up only in cryo cold conditions it could well
be due to thermal contraction of some parts somewhere. Thats more
or less a mechanical problem affecting the electrical system of
at least one sensor system now. But if the Shuttle launches the


Not necessarily. The extremely low temps can cause mechanical problems
insofar as thermal contraction of materials, but there are other
possible effects that are not mechanical at all, i.e. electrical
resistance in metal changes with temperature independent of mechanical
factors.

extraordinary vibrations could well have a similar effect like the
thermal contraction. It could affect the other 3 sensor systems


You can't equate mechanical vibration to thermal contraction. Thermal
testing is conducted quite separately from vibration testing. By your
reasoning, one could do only vibration testing and dispense with thermal
testing altogether, since the mechanical response of the system would
account for all thermal response as well. The two are not the same,
however.

wiring/grounding even more than the thermal contraction of the one
system we know from. So I see no evidence that the problem is
not generic to the whole fleet now.


That's quite a leap.

extraordinary vibrations could well have a similar effect like the
thermal contraction. It could affect the other 3 sensor systems

You can't equate mechanical vibration to thermal contraction. Thermal
testing is conducted quite separately from vibration testing. By your
reasoning, one could do only vibration testing and dispense with thermal
testing altogether, since the mechanical response of the system would
account for all thermal response as well. The two are not the same,
however.

Sure, not the same. But you will agree that under some conditions
(poor ground patch for example) vibration can have a similar effect
like thermal contraction.

wiring/grounding even more than the thermal contraction of the one
system we know from. So I see no evidence that the problem is
not generic to the whole fleet now.

That's quite a leap.

See it from another way. We will agree that by some probability the
ECO problem is an age related one. Probably in the Shuttle, not the
ET. From that view its not a large leap to consider the whole fleet
suspect.

I read about the repair of 3 or 4 ground patches to get them to the
specs again. But how many such patches has the Shuttle? Could be
closer to 100 than 10. And any of this connections could be related
to the ECO problem.



## CrossPoint v3.12d R ##