Peter Munn wrote:

I haven't done the detailed calculations for this, but it may be
possible to achieve another rendezvous with Jupiter one and a half
orbits later (if not, then two and a half orbits, or half a century,
later). This time your ark will be approaching Jupiter's orbit from the
North or South and you will have the 12km/sec relative approach speed
that you need.

This final assist will need to occur when Jupiter is in the part of its
orbit where its velocity is directed in the general direction of where
Alpha Centauri will be in 50,000 years' time.

Hi Peter,
Thanks very much for these pointers, really appreciated.
They should come in handy if someone actually decides to build this
thing (for real!) one day... who knows!?

Abdul