Thanks for mentioning this. I did a bit of reading about the special alignment - very interesting stuff!
It seems like the alignment you refer to inspired the launch of Voyager 1 and 2 because they could visit so many planets at one time, and indeed it did slingshot them at quite some speed. However newer launches have reached similar speeds, and will escape the solar system due to improvements in launch technology.
It seems like the alignment you refer to inspired the launch of Voyager 1 and 2 because they could visit so many planets at one time, and indeed it did slingshot them at quite some speed. However newer launches have reached similar speeds, and will escape the solar system due to improvements in launch technology.