The first tin whisker report came 1954. Already covered most you need to know!! I have a copy if someone want. Inge On 21 March 2012 22:51, David D. Hillman <[log in to unmask]>wrote: > Hi Bob - Outstanding! I anticipate an informative presentation on the > situation as the NASA group always has great information. > > Dave > > > > Bob Landman <[log in to unmask]> > Sent by: TechNet <[log in to unmask]> > 03/21/2012 10:45 AM > Please respond to > Bob Landman <[log in to unmask]> > > > To > <[log in to unmask]> > cc > > Subject > Re: [TN] Out of the world tin whiskers > > > > > > > Hi Dave, > > Henning Leidecker has confirmed to me that his group (Henning, Jay and > Lyudmyla) at NASA Goddard SFC was on the committee that that determined > the problem was indeed tin whiskers. > > Bill Rollins has offered Henning the opportunity to present their findings > to our weekly tin whiskers teleconference. Hopefully we'll hear about it > soon. > > Bob Landman > LDF Coatings, LLC > www.ldfcoatings.com > H&L Instruments, LLC > > -----Original Message----- > From: TechNet [mailto:[log in to unmask]] On Behalf Of David D. Hillman > Sent: Tuesday, March 20, 2012 6:15 PM > To: [log in to unmask] > Subject: Re: [TN] Out of the world tin whiskers > > Hi Pat and gang - good information as our "industry attention" on the > topic of tin whiskers pre-1997 was not at the same level of scrutiny as we > have today. This failure, if it has a tin whisker root cause, is a > demonstration of two things: (1) the breakdown of system rules prohibiting > the use of pure tin in a space application. NASA has always attempted to > avoid the use of pure tin due to the tin whisker risk. There may have been > a simple human error or this could have been a lack of knowledge by a > supplier; (2) the lack of a tin whisker mitigation strategy. If there was > going to be the use of pure tin in a space application, was a tin whisker > mitigation methodology missed - such as pretinning the leads, adequate > design spacing or the use of a coating material to capture/contain the > whiskers? Easy to second guess what happened. Hopefully, further details > of the story will be published so that we can learn from the issue. > > Dave Hillman > Rockwell Collins > [log in to unmask] > > > > > "Goodyear, Patrick" <[log in to unmask]> > Sent by: TechNet <[log in to unmask]> > 03/20/2012 02:33 PM > Please respond to > TechNet E-Mail Forum <[log in to unmask]>; Please respond to > "Goodyear, Patrick" <[log in to unmask]> > > > To > <[log in to unmask]> > cc > > Subject > Re: [TN] Out of the world tin whiskers > > > > > > > To answer my own question. > > Cassini was launched October 15,1997, so it was most likely built in > '96-'97 timeframe. I don't think lead free had hit the streets by then > except for applications in plumbing. Whiskers had been an issue long > before that, at least in my industry. We have been inspecting for them > since around 1992, we tripped a unit in 1988 due to a whisker in a relay, > shorting out a contact that should have opened when the relay energized. > > pat > > -----Original Message----- > From: TechNet [mailto:[log in to unmask]] On Behalf Of Goodyear, Patrick > Sent: Tuesday, March 20, 2012 11:11 AM > To: [log in to unmask] > Subject: Re: [TN] Out of the world tin whiskers > > But Cassini is a bunch of years old, at least 10 I think. The components > are most likely plated leads on diodes or tin canned pots. > > Pat > > -----Original Message----- > From: TechNet [mailto:[log in to unmask]] On Behalf Of Dale Ritzen > Sent: Tuesday, March 20, 2012 11:00 AM > To: [log in to unmask] > Subject: Re: [TN] Out of the world tin whiskers > > Joyce, > I know your question below is basically rhetorical, but have you tried to > find a component without a Pb-free coating on it lately... That is, > unfortunately, why there are Pb-free components on spacecraft... and > obviously tin whiskers. > > Dale Ritzen, CQA > Quality Manager / ISO Management Representative Austin Manufacturing > Services > > > -----Original Message----- > From: TechNet [mailto:[log in to unmask]] On Behalf Of Joyce Koo > Sent: Tuesday, March 20, 2012 12:57 PM > To: [log in to unmask] > Subject: Re: [TN] Out of the world tin whiskers > > I thought space is exempt for leadfree. Why? > -------------------------- > Sent using BlackBerry > > > ----- Original Message ----- > From: Inge Hernefjord [mailto:[log in to unmask]] > Sent: Tuesday, March 20, 2012 01:47 PM > To: [log in to unmask] <[log in to unmask]> > Subject: Re: [TN] Out of the world tin whiskers > > DO THEY NEVER LEARN! > > Inge > > On 20 March 2012 18:08, Gervascio, Thomas L > <[log in to unmask]>wrote: > > > Tin whiskers at Saturn > > > > PASADENA, Calif. -- The Cassini plasma spectrometer instrument (CAPS) > > aboard NASA's Cassini spacecraft at Saturn has resumed operations. > > Mission managers received confirmation on Friday, March 16, that it was > turned on. > > They plan to monitor the instrument for any unusual behavior. > > Last June, short circuits in the instrument led to unexpected voltage > > shifts on the spacecraft. As a precaution, mission managers turned off > > the CAPS instrument while engineers investigated the issue. The > > investigation led to the conclusion that tin plating on electronics > > components had grown "whiskers." The whiskers were very small, less > > than the diameter of a human hair, but they were big enough to contact > > another conducting surface and carry electrical current. Researchers > > are still trying to understand why whiskers grow on tin and other > > metals, but they know now that whiskers can grow in space and on > > Earth. It is believed that these or additional tin whiskers that may > > grow on Cassini cannot carry enough current to cause problems, but will > burn out on their own like a lightweight fuse. > > > > > > > > ______________________________________________________________________ > > This email has been scanned by the Symantec Email Security.cloud > service. > > For more information please contact helpdesk at x2960 or > > [log in to unmask] > > ______________________________________________________________________ > > > > > ______________________________________________________________________ > This email has been scanned by the Symantec Email Security.cloud service. > For more information please contact helpdesk at x2960 or [log in to unmask] > ______________________________________________________________________ > > --------------------------------------------------------------------- > This transmission (including any attachments) may contain confidential > information, privileged material (including material protected by the > solicitor-client or other applicable privileges), or constitute non-public > > information. 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