An unmanned spacecraft carrying 2.5 tons of supplies and 50 snails headed to the International Space Station Saturday after being launched from Kazakhstan.

The Russian-built Progress 25 spacecraft was fired into space Friday night atop a Soyuz rocket from Baikonur Cosmodrome, the space.com Web site reported. It will reach the space station Tuesday with its cargo of more than 5,000 pounds of food, fuel, air, water and other vital supplies and equipment.

The spacecraft's cargo also includes 50 snails to be studied in experiments on tissue regeneration in zero gravity, the Russian news agency Interfax reported.

The Institute for Medical and Biological Problems said the spacecraft carried a selection of movies on DVD -- mainly comedies -- requested by crewmembers and recommended by experts.

"The psychological support team is also sending several magazines and books requested by crewmembers," an institute spokesman said.

NASA said the Expedition 15 crew trained Friday with the telerobotically operated rendezvous system that would manually guide in the cargo craft for docking in the event its automated system encountered a problem.

The crew -- Russian cosmonauts Fyodor Yurchikhin and Oleg Kotov and NASA astronaut Sunita Williams -- has been onboard the ISS since December.

Copyright 2007 by United Press International