Solar Oberth meneuver FTW! ;-) https://www.universetoday.com/154791/the-best-way-to-leave-the-solar-system-might-be-to-fly-uncomfortably-close-to-the-sun/ http

Solar Oberth meneuver FTW! ;-) https://www.universetoday.com/154791/the-best-way-to-leave-the-solar-system-might-be-to-fly-uncomfortably-close-to-the-sun/ https://www.universetoday.com/154791/the-best-way-to-leave-t... (I have also seen a variant with an upper stage class SRB used for the meneuver.)