Ybys - definition please

I have encountered this term and cannot find a definition for it. Can anyone assist please?

Where did you encounter it Diane?

Hi Diane,

I found it in several papers on interplanetary flight like like this one,

The rst yby at Venus on 26 April 1998 gave Cassini an extra 7 km/s or so, the third at Earth on 17 August 1999 added 5.5 km/s. The fourth and last yby, at Jupiter on 30 December 2000, added 2 km/s
and set Cassini on course to arrive at Saturn on 1 July 2004.

If this is the context you saw it in then I assume that it should read "flyby". You will also notice that whatever program converted these texts also dropped the "fi" from first (the second word). When I do a search of one of these documents there is no occurrence of "fl" anywhere in the documents, which seems odd. Strange :

To me, it should be "flyby".
Can't see what else it would be.

I wonder would it be some issue of character recognition scanning in documents perhaps???

Yup.Its plural.It's short for "Fly-bys".

First, please ignore accidentally duplicated message about this 'ybys' thing.

Secondly - very disappointing.... the same word (and this time really a word) is found in an old document. No-one knows what it meant and I thought I was onto something astronomical.... :oops:

Thanks all.
D.