SARJ

What's the latest on the SARJ damage/repair?

What's the latest on the SARJ damage/repair?

The latest that I read was from November 24, 2007 and said that they
did a spacewalk which gave them new information about what is broken,
but don't seem to yet have decided how/when to fix it:
http://spaceflightnow.com/news/n0711...va/index3.html

Perhaps there is something more recent. According to that article
something needs to be done before Kibo is to be launched (currently
April).

On 29 Nov 2007 16:24:42 -0500, Jim Kingdon wrote:

What's the latest on the SARJ damage/repair?

The latest that I read was from November 24, 2007 and said that they
did a spacewalk which gave them new information about what is broken,
but don't seem to yet have decided how/when to fix it:
http://spaceflightnow.com/news/n0711...va/index3.html

Perhaps there is something more recent. According to that article
something needs to be done before Kibo is to be launched (currently
April).
It might be that the two SARJs were manufactured slightly
different. The debris have been analyzed as being a nitride
finish on the race way that seems to be spalling off. The other
SARJ may not have the same or any nitride finish.
Normally a nitride finish would improve the machine. But
perhaps not in space.
Metals in contact in vacuum may have a greater tendency to spall
than in normal atmosphere. Spalling seems somewhat mysterious,
as does nitride finishing.
Wiki reference : http://en.wikipedia.org/wiki/Spall

Sir Frederick wrote:

On 29 Nov 2007 16:24:42 -0500, Jim Kingdon wrote:

What's the latest on the SARJ damage/repair?

The latest that I read was from November 24, 2007 and said that they
did a spacewalk which gave them new information about what is broken,
but don't seem to yet have decided how/when to fix it:
http://spaceflightnow.com/news/n0711...va/index3.html

Perhaps there is something more recent. According to that article
something needs to be done before Kibo is to be launched (currently
April).
It might be that the two SARJs were manufactured slightly
different. The debris have been analyzed as being a nitride
finish on the race way that seems to be spalling off. The other
SARJ may not have the same or any nitride finish.
Normally a nitride finish would improve the machine. But
perhaps not in space.
Metals in contact in vacuum may have a greater tendency to spall
than in normal atmosphere. Spalling seems somewhat mysterious,
as does nitride finishing.
Wiki reference : http://en.wikipedia.org/wiki/Spall


Well, let's not forget the EVA crew lost two cover bolts on that joint. One
of them could be up in the mechanism.

Mike Ross

"Mike Ross" wrote in message
. ..
Sir Frederick wrote:
It might be that the two SARJs were manufactured slightly
different. The debris have been analyzed as being a nitride
finish on the race way that seems to be spalling off. The other
SARJ may not have the same or any nitride finish.
Normally a nitride finish would improve the machine. But
perhaps not in space.
Metals in contact in vacuum may have a greater tendency to spall
than in normal atmosphere. Spalling seems somewhat mysterious,
as does nitride finishing.
Wiki reference : http://en.wikipedia.org/wiki/Spall


Well, let's not forget the EVA crew lost two cover bolts on that joint.
One
of them could be up in the mechanism.

This would actually be a good thing to discover, since a manufacturing
defect in the raceway, like a nitride finish, would likely be on the other
(backup) side of the defective raceway.

From what I remember reading the raceways were manufactured to be double
sided, so you have a backup side available. The downside to this is that
NASA isn't sure how many EVA's would be required to flip the raceway(s) and
replace all the other damaged components.

Jeff
--
A clever person solves a problem.
A wise person avoids it. -- Einstein

Jeff

Surely though, if it were a bolt which is causing it, some debris from the
bolt, which, one assumes, is of softer material than the race, should be in
all the samples.

It has to be either problem manufacturer, or debris though, as the other
joint is still clean.

Brian

--
Brian Gaff -
Note:- In order to reduce spam, any email without 'Brian Gaff'
in the display name may be lost.
Blind user, so no pictures please!
"Jeff Findley" wrote in message
...

"Mike Ross" wrote in message
. ..
Sir Frederick wrote:
It might be that the two SARJs were manufactured slightly
different. The debris have been analyzed as being a nitride
finish on the race way that seems to be spalling off. The other
SARJ may not have the same or any nitride finish.
Normally a nitride finish would improve the machine. But
perhaps not in space.
Metals in contact in vacuum may have a greater tendency to spall
than in normal atmosphere. Spalling seems somewhat mysterious,
as does nitride finishing.
Wiki reference : http://en.wikipedia.org/wiki/Spall


Well, let's not forget the EVA crew lost two cover bolts on that joint.
One
of them could be up in the mechanism.

This would actually be a good thing to discover, since a manufacturing
defect in the raceway, like a nitride finish, would likely be on the other
(backup) side of the defective raceway.

From what I remember reading the raceways were manufactured to be double
sided, so you have a backup side available. The downside to this is that
NASA isn't sure how many EVA's would be required to flip the raceway(s)
and replace all the other damaged components.

Jeff
--
A clever person solves a problem.
A wise person avoids it. -- Einstein

Jeff

On 29 Nov, 19:06, Mike Ross
wrote:
Sir Frederick wrote:
On 29 Nov 2007 16:24:42 -0500, Jim Kingdon wrote:

What's the latest on the SARJ damage/repair?

The latest that I read was from November 24, 2007 and said that they
did a spacewalk which gave them new information about what is broken,
but don't seem to yet have decided how/when to fix it:
http://spaceflightnow.com/news/n0711...va/index3.html

Perhaps there is something more recent. According to that article
something needs to be done before Kibo is to be launched (currently
April).
It might be that the two SARJs were manufactured slightly
different. The debris have been analyzed as being a nitride
finish on the race way that seems to be spalling off. The other
SARJ may not have the same or any nitride finish.
Normally a nitride finish would improve the machine. But
perhaps not in space.
Metals in contact in vacuum may have a greater tendency to spall
than in normal atmosphere. Spalling seems somewhat mysterious,
as does nitride finishing.
Wiki reference :http://en.wikipedia.org/wiki/Spall

Well, let's not forget the EVA crew lost two cover bolts on that joint. One
of them could be up in the mechanism.

Mike Ross- Hide quoted text -

- Show quoted text -

Actually the lost bolts and washers were on the other side of the
station (P3/P4 truss segment). One did however get "lost" inside the
truss.
http://space.newscientist.com/article/dn10067

The broken SARJ is on the S3/S4 truss segment.