What's the next step?

[prestidigitator]

Re: What's the next step?

 

My bet is on ion drives rather than nuclear propulsion, but most likely there'll be some kind of hybrid approach. Decelerating isn't that big of a deal, as it is generally symmetrical with the problem of accelerating toward the destination (though there are possible solutions for decelerating that will take less active propulsion, such as magnetic sails).

 

We don't have to worry much about solar escape velocity, by the way, since we are starting off in pretty high solar orbit (meaning we already have almost enough speed/energy to essentially be "free" of the Sun's gravity; the difference in velocity between Earth's orbit and solar escape velocity is 12 km/s--paltry compared to the kind of speeds we'll be interested in for interstellar travel, and actually about equal to Earth's escape velocity from the surface of the planet so it's the kind of magnitude we're used to dealing with). We've already sent probes (such as Voyager 1 and Voyager 2) into the outer regions of the heliosphere, where they continue to collect data. It's more a matter of how much time it takes to get out there than whether it can be done at all.