If you want to use this method, you're basically going to require one spacecraft per target and a decade of lead time for a very short-duration observation. Th

If you want to use this method, you're basically going to require one spacecraft per target and a decade of lead time for a very short-duration observation. This is not necessarily a deal-breaker; Meaningful scientific inquiry would just require we mass produce them. We already sabotage ourselves in astronomy by refraining from mass production approaches for political reasons. There is no practical amount of fuel that can get you to 500AU on a simple trajectory. What seems to be the best option for setting massive vehicles on a solar escape is a sequence that looks something like: * Launching to Jupiter propulsively * Cancelling out most solar-orbital velocity there using a gravity assist in order to dive down into a sun-skimming orbit * Burning through a large solid state rocket kick stage while at close approach to the sun from behind a heat shield. The Oberth Maneuver. * (optional) unfurling an electric sail or solar sail once the rocket has finished as you're speeding away from Sol Together that gets you the required ~100AU/year escape for a mass fraction that is tractable for our civilization.