A new kind of starship.
The huge distances between Earth and the nearest star make it necessary for us to conceive of extremely high-velocity starships if interstellar travel is to be possible with durations less than a human lifetime. In practise this means accelerating the starship to some percent of lightspeed. The problem with doing this, of course, is that truly phenomenal amounts of power are required to boost a ship to such velocities.[1]
Various propulsion schemes have been proposed, from nuclear fusion to antimatter to laser sails. Until recently, laser sailing seemed like the most economical and easiest way, even though it still requires that we build lasers that draw more power than all of human civilization is now capable of producing. [Author’s note: since I first wrote this a method has been proposed that could amplify a laser launcher’s power by factors of tens of thousands. So I guess laser launch is back on the table.].
