> Lubin supposes that the system could propel crafts to an "unheard of" 30 percent the speed of light. > "There is no known reason why we could not do this" Y

> Lubin supposes that the system could propel crafts to an "unheard of" 30 percent the speed of light. > "There is no known reason why we could not do this" Yeah, no. There is a known reason. What do you think happens to a spaceship hitting something at 30% c? What do you think happens to the front of a spaceship or craft hitting something the size of bead or pebble at 30% c? The ship will disintegrate. Granted, the ship could be shielded or employ some sort of plasma/magnetic deflector technology (still in proof of concept stages of development), but now you're talking technology that's just as far away, if not further than the propulsion system they're talking about using. It's also why things like project Orion really never got off the ground or are feasible in their current forms. Sure, we can get up to those speeds, it's surviving at those speeds that's the challenge. Also, they talk about the weight of a ship being ultra light. If you had to shield it to survive the impact of tiny particles and other space debris you'll inevitably encounter on your trip, it's no longer going to be ultra light.