] The pair were testing a very thin carbon-mesh sail by ] firing microwaves at it. To their surprise, the sail ] experienced a force several times stronger than they ] expected. They eventually worked out that the heat from ] the microwave beam was causing carbon monoxide gas to ] escape from the sail's surface, and that the recoil from ] the emerging gas molecules was giving the sail an extra ] push. [ Very cool. 60 MW is a lot of microwaves, but it's a neat concept. Incidentally, one of the brothers is Gregory Benford, who's written a number of well known SciFi novels. -k] |