Gregory Benford, professor of physics at UC Irvine (and noted science fiction author) believes that a spacecraft powered by a special kind of solar sail could reach Mars in just one month. Dr. Benford and his brother James were testing a very thin carbon-mesh sail, using microwaves as the energy source for propulsion. Unexpectedly, the sail experienced a force considerably greater than predicted. They theorized that the heat from the microwave beam was causing carbon monoxide gas to escape from the sail’s surface; the recoil from the escaping molecules provided what could be a useful adjunct to the propulsive force experienced by light sails.