Russian and U.S. space workers put finishing touches Monday to a craft they hope will orbit Earth powered only by the sun's rays.

"The design life for this mission is only a month," said Louis Friedman, project director for the Cosmos 1 venture. "It could go longer, but not much. What we want to do is prove that it works — that we can increase orbit energy and make it fly higher."

The craft is to be launched by a Russian submarine in the Barents Sea Tuesday using a leftover Soviet ballistic missile to place it in orbit 500 miles up, The Washington Post said.

The spacecraft weighs 231 pounds, and contains the electronics that enable the sail to send and receive signals from the ground. The solar-sail assembly, which weighs an additional 88 pounds, is composed of eight 50-foot-long sail segments made of thin Mylar-like material.

Ground-based engineers should be able to steer the solar sail back and forth in space, Friedman said, "tacking it, like a sailboat — although the physics are different."