New Scientist is carrying this article detailing a new development in solar-sail research:
Gregory Benford of the University of California, Irvine, and his brother James, who runs aerospace research firm Microwave Sciences in Lafayette, California, envisage beaming microwave energy up from Earth to boil off volatile molecules from a specially formulated paint applied to the sail. The recoil of the molecules as they streamed off the sail would give it a significant kick that would help the craft on its way. "It's a different way of thinking about propulsion," Gregory Benford says. "We leave the engine on the ground."
It's actually not all that different, since the concept is found in dozens of science fiction books, some of which Benford has probably written himself. And that's the other thing... I find it really odd Ms. Biever seemed to completely ignore the fact that Greg Bendford is an award-winning SF author. I could understand that if he'd only written one or two books decades ago, but this guy's got dozens of titles on the shelf right now.
At any rate, the concept is fun to think about (Mars in a month is certainly cool), but would require the development of a microwave generator some 120 times more powerful than anything that exists today. Can you say pipe dream? I knew you could...