After a failure, a new craft to sail.

Engineers have long envisioned replacing heavy rocket fuels with a solar sail that would use the steady push of sunlight against an ultrathin, highly reflective surface (SN: 8/21/99, p. 120). They're getting closer to propelling a spacecraft in this way.

Despite the July 20 failure of its mission to test the unfurling of a solar sail in a suborbital trajectory, the Planetary Society of Pasadena, Calif., announced plans last month to conduct a second test of a sail-propelled craft. Scheduled for launch early next year, the craft would evaluate for the first time both the deployment and operation of a solar sail in full orbit around Earth.

The July mission was launched from a Russian submarine in the Barents Sea, but the third stage of the launch rocket, a converted intercontinental ballistic missile, did not separate. Therefore, the blades of the solar sail never inflated.

The new craft, which is part of the privately funded Cosmos 1 project, also will be launched from the Barents Sea, says Louis J. Friedman, executive director of the society. The project aims to use the solar-powered sail to slowly expand the orbit of a spacecraft, moving it farther and farther from Earth.