universal science: This rocket would be capable of accelerating a 450 tonne payload to about 12% of the speed of light (which would get to the nearest star in about 36 years). by Ian Crawford
'The concept is currently being revisited and updated by the ongoing Project Icarus study. Unlike Daedalus, Icarus will be designed to slow down at its destination, permitting scientific instruments to make detailed measurements of the target star and planets.
'All current starship concepts are designed to be built in space. They would be too large and potentially dangerous to launch from Earth. What’s more, to get enough energy to propel them we would need to learn to collect and manage large amounts of sunlight or mine rare nuclear isotopes for nuclear fusion from other planets. This means that interstellar space travel is only likely to become practical once humanity has become a spacefaring species.
'The road to the stars therefore begins here – by gradually building up our capabilities. We need to progressively move on from the International Space Station to building outposts and colonies on the Moon and Mars (as already envisaged in the Global Exploration Roadmap). We then need to begin mining asteroids for raw materials. Then, perhaps sometime in the middle of the 22nd century, we may be prepared for the great leap across interstellar space and reap the scientific and cultural rewards that will result.'
"AVOIDING INTELLECTUAL STAGNATION: THE STARSHIP AS AN EXPANDER OF MINDS" by I.A. Crawford (pdf) here
'A Comment on “The Far Future of Exoplanet Direct Characterization”—The Case for Interstellar Space Probes' by Ian A. Crawford here