A spacewalking astronaut tossed two large chunks of junk off the international space station yesterday, hurling the old equipment into orbit.

Clayton Anderson, a sportsman who enjoys officiating basketball games back on Earth, heaved a 635-kilogram, refrigerator-size ammonia tank away from the station. His first toss was a 90-kilogram camera mounting. Using baseball terminology, Mission Control declared the tank throw great and "right down the middle."

"Well, in that case, give Brad Lidge and Roy Oswalt a call and tell them I just hummed a 17,500-mph fastball," Anderson said, referring to the star pitchers for his hometown Houston Astros.

Anderson said the tank looked "majestic" as it tumbled away, and the 1.22-meter camera mounting resembled "a huge star."

"I'll be sending my bill in the mail for trash disposal," he joked with Mission Control.

For each celestial toss, Anderson leaned back on the end of the space station's 17.7-meter robot arm, as far from the space station as possible. He rocked forward and shouted "Jettison!" as he shoved the outdated camera mounting into space. The bulkier ammonia tank was a bit trickier.

The ammonia tank had been launched in 2001 to provide spare coolant in case of a leak at the orbiting complex. The surplus ammonia was never needed, and the tank itself had exceeded its life expectancy.

NASA normally tries to avoid adding to the orbiting junkyard, but officials felt they had no choice in this case. The equipment had to be removed, and because of a looming 2010 deadline for ending all shuttle flights, NASA does not have room on its remaining missions to return the tank to Earth.

Flight controllers expect the ammonia tank to orbit for 10 or 11 months before re-entering the atmosphere and burning up.