Russia's Federal Space Agency said ISS Expedition 14 Commander Michael Lopez-Alegria and Flight Engineer Mikhail Tyurin will step out of the orbital station at 11 p.m. GMT.
Their almost six-hour-long extravehicular activity will include routine repairs, specifically to an antenna of the Progress M58 cargo spacecraft, and a round of golf, to be played under a contract with an American sports equipment company.
"Two golf clubs and four balls, of a well-known U.S. make, are now sitting on board the ISS," agency spokesman Igor Panarin said. "As he emerges into open space in an Orlan spacesuit, the Russian cosmonaut Mikhail Tyurin will swing one of the balls away from the ISS in a well-directed stroke."
Lopez-Alegria will be on hand with a video and a photographic camera to capture the dramatic image of a white ball flying through the interplanetary darkness.
The previous ISS crew - Expedition 13 Commander Pavel Vinogradov of Russia and Science Officer Jeffrey Williams, of the United States - failed to go down in history as the world's first space golfers.
"Back then, this promotional event was put off at NASA's request as potentially dangerous - [the U.S. Aeronautics and Space Administration said] a golf ball launched into outer space with high acceleration may end up boomeranging the ISS," a Mission Control official said. "But now the Americans have changed their minds."
Russian experts argue, however, that a golf ball, which they see as space litter if thrown into outer space, will pose no danger either to the ISS or to any of the satellites orbiting the Earth, as it will be flung on an orbit where no collision may occur. It is expected to subsequently reenter the Earth's atmosphere and burn up.
