Two crew members aboard the International Space Station have completed a successful spacewalk Monday morning, dumping some obsolete equipment and preparing the outpost for future assembly missions, according to NASA TV.

The duo stepped out of the Quest Airlock at 6:24 EDT (1024 GMT) Monday. NASA astronaut Clayton Anderson is the lead sapcewalker, wearing the spacesuit with red stripes. Fyodor Yurchikhin, the Russian cosmonaut and station commander, wearing the all-white suit, is the second spacewalker.

Riding on the end of the space station's robotic arm maneuvered by Flight Engineer Oleg Kotov inside station, Anderson jettisoned a refrigerator-size ammonia tank by shoving it opposite of the station's direction of travel. He also rid the orbiting complex of an outdated camera mounting.

They also installed a television camera stanchion,reconfigured a power supply for an antenna assembly, and performed several get- ahead tasks.

The excursion lasted for seven hours and 41 minutes, and the two astronauts have got back into the Airlock safely at 2:05 p.m. EDT (1805 GMT).

Normally, NASA tries to avoid littering in space, but they have no other choice this time. The ammonia tank was no longer needed and it has to be removed. Since the U.S. space shuttle fleet is to be retired in 2010, NASA officials could not make room in a shuttle cargo bay to transport the junk equipment back to Earth.

A few hours after the spacewalk, a docked Progress 25 cargo craft will fire its thrusters raising the station's orbit. This reboost, along with a reboost performed Friday, provides the proper phasing for an upcoming Progress 26 launch and docking.

Moreover, Progress 25 firing also clears the station and provides docking opportunities when space shuttle Endeavor arrives on mission STS-118, which is scheduled to launch on Aug. 7.