Space Station Crew Discards Unmanned Cargo Ship
A docking port at the aft of the International Space Station's Zvezda service module (far right in this depiction) is now clear after the undocking of a Russian-built Progress 19 cargo ship on March 3, 2006. The Progress 20 cargo tug (docked at Pirs compartment at mid-right) and Soyuz TMA-7 vehicle (center at Zarya module) are also shown.
Credit: NASA/JSC.

Two astronauts cast off a spent cargo ship from the International Space Station (ISS) early Friday in move that will free up a docking port outside the orbital laboratory.

ISS Expedition 12 commander Bill McArthur and flight engineer Valery Tokarev undocked the Russian-built Progress 19 vehicle, an unmanned supply ship that sat at the aft end of the station's Zvezda service module since its Sept. 10 arrival.

McArthur and Tokarev crammed Progress 19 with trash, unneeded equipment and clothes and siphoned its last remaining supplies of water and oxygen before undocking it at 5:06:10 EST (1006:10 GMT) Friday. After a brief engine firing to fly clear of the space station, the Progress 19 vehicle began its Earthward descent and is expected to burn up in the planet's atmosphere.

Some parts of the spacecraft may survive atmospheric reentry and plummet into the Pacific Ocean about 1,864 miles (3,000 kilometers) east of Wellington, New Zealand, Russian ISS mission control spokesperson Valery Lyndin told the Interfax News Agency.

Progress 19's departure clears the way for a brief spaceflight on March 20 by the Expedition 12 astronauts. McArthur and Tokarev are expected to relocate their Soyuz TMA-7 vehicle from its berth at the Earth-facing port on the station's Zarya control module in anticipation of their relief crew's arrival.

In a daily ISS update, NASA spokesperson Rob Navias said the "Progress and Soyuz shell game" clears the Zarya docking port for Expedition 13 commander Pavel Vinogradov, flight engineer Jeffrey Williams and Marcos Pontes - Brazil's first astronaut. Pontes and the Expedition 13 crew will launch from Baikonur Cosmodrome in Kazakhstan on March 29 at 9:30 p.m. EST (0230 March 30 GMT) and dock the station two days later.

During their short spaceflight, McArthur and Tokarev will each don their Russian-built Sokol spacesuits, climb inside their Soyuz vehicle and undock from the ISS at 1:45 a.m. EST (0645 GMT). By 2:22 a.m. EST (0722 GMT), they should arrive at the station's Zvezda berth, NASA officials said.

McArthur and Tokarev are less than six weeks away from completing their six-month mission aboard the ISS. The two astronauts arrived aboard the station in October 2005 and are expected to return to Earth with Pontes in early April.

While Progress 19 has left the ISS, another unmanned cargo ship remains parked at the station's Pirs docking compartment. That resupply ship, Progress 20, arrived at the ISS on Dec. 23.