Anyone that claims our understanding of the universe is absolute is poorly informed. It's entirely possible that an incredible discovery is just around the corner, in fact it's possible that it has already been made, but nobody noticed and it languished as some ones play thing for a few weeks before they got bored and dumped it not realising its significance.
Much like this http://dimdima.com/science/science_common/show_science.asp?q_aid=156&q_title=The+First+Steam+Engine
Imagine how much different the world would be if the industrial revolution happened in 100AD, it didn't though as it was seen more as a plaything.
What the technology that will allow star travel will be like is a mystery (if it is possible) but one can assume 3 basics components will be required - an ability to travel vast distances, an ability to protect the inhabitance of a ship from the dangers of space, the method of travel, and any issues that occur at the end point and, a power source.
Another important pre step will be establishing a lasting presence on the various moons and planets that make up our solar system.
But without a goal why would we ever try, imagination and hope are what push people forward, if everyone went "well what's the point of trying something new" we'd all be roaming the land a lot like the various predators of the wilds.