On Sat, 5 Jan 2019 17:04:36 +0100, Thomas 'PointedEars' Lahn
wrote:

Its trajectory is hyperbolic; it WILL leave the Solar System,
and there's no way to change that.

Incorrect.

Unless you propose that there is another object almost exactly in its
path, and we divert it to strike that object, then there is, in fact,
absolutely nothing we can do to prevent it from leaving the Solar
System.

It was always understood that its trajectory would cause it to do so.

Since we have almost no idea what is in the Sol System beyond Ultima Thule,
this is not only an unfounded, but utterly ridiculous claim.

What are you talking about? How does it matter what else lies in the
outer Solar System?

It is the purpose of this mission extension to investigate the Kuiper Belt,
not to make an interstellar probe out of NH.

We've never had a mission with purpose of being an interstellar probe.
The fact that some have become so is secondary to the trajectories
that were created in order for them to perform their mission within
the Solar System.

Neither Pioneer nor Voyager were designed to leave the Solar System.
There was simply no way to keep them in a closed orbit around the Sun.