The marketplace.org article quotes Bob Tjoelker as saying his team, and 
deep-space missions in general, can handle leap seconds.   I've known Bob 
Tjoelker for years.   He's a super-scientist designing super-clocks.  Since 
some of those clocks are space-qualified, he is literally a rocket scientist.   
But it should also be noted that the marketplace.org article did not point out 
that most of us are not at his level.   Also, they chose not to quote him about 
concerns he expressed about other systems.

As an example, last week some GPS receivers (of different models) apparently 
implemented the coming leap second as soon as GPS  began broadcasting its 
leapsecond-pending flag.  While their jumps could have been due to something 
else, and the receivers did not jump with the last leap second, the coincidence 
raises strong suspicions that the receivers were misprogrammed.    This failure 
was discovered because the receivers' associated NTP servers gave out the wrong 
time.  For reference see 
http://lists.ntp.org/pipermail/pool/2015-January/007272.html.

Equally unfortunate is that 30 servers in the NTP pool inserted a leap second 
last Dec 31.  Even if a DNS-based reference helps with some of these issues, 
there would remain a host of other opportunities for failure, such as systems 
mis-programmed so they insert leap seconds after 23:59:59 local time instead of 
UTC.

As always these are my personal opinions, and not those of my employer or the 
US Government.   In that sense I note that NASA is very good at proactively 
preventing mistakes, and I suspect this consideration contributed to its 
anti-leapsecond position, which itself contributed the American government's 
decision to support the proposal calling for the elimination of future leap 
seconds after the suitable waiting period.

-----Original Message-----
From: LEAPSECS [mailto:[email protected]] On Behalf Of Brooks 
Harris
Sent: Sunday, January 25, 2015 11:35 AM
To: Leap Second Discussion List
Subject: [LEAPSECS] The leap second, deep space and how we keep time -Brooks

The leap second, deep space and how we keep time 
http://www.marketplace.org/topics/world/leap-second-deep-space-and-how-we-keep-time

Much less stupid than many popular reports...

-Brooks
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