Spacewalker tosses tank overboard

A coolant tank the size of a refrigerator is tumbling through orbit near the International Space Station after an astronaut tossed it overboard as part of a spacewalking disposal job.

Flight engineer Clay Anderson was anchored to the end of the station's 57-foot robot arm, which had been extended to a point behind and below the outpost. Holding the 1,400-pound ammonia reservoir by handrails, Anderson leaned back, rocked forward and put some oomph behind an orbital push.

The Early Ammonia Servicer slowly moved off in the wake of the station as both sped around Earth at five miles per second.














"Clay, we're looking at all the camera views, and we think you had a great throw. It looks straight down the middle," NASA astronaut Chris Cassidy said from the agency's Mission Control Center in Houston.

Well in that case....I just hummed a 17,500-mph fast ball," Anderson replied.

The station will be hauled into a higher orbit later today to avoid the chance that the tank might come back around and strike the outpost on a subsequent orbit. Filled with toxic ammonia, the reservoir is expected to reenter Earth's atmosphere in 300 to 330 days.

NASA flight directors say it will not endanger other spacecraft in low Earth orbit or the shuttle Endeavour during its trip to the outpost next month. Any pieces that survive reentry are expected to fall in the ocean.

Launched to the station in August 2001, the ammonia tank had been hooked up to a temporary cooling system designed to operate during the early stages of outpost assembly. The station's permanent cooling system was activated in December, and the tank no longer is needed.

In addition, it had to be moved from the truss it was mounted to so the girder can be moved later this year to the end of the port side of the station's metallic backbone.

Anderson and Yurchikhin now are cleaning a berthing mechanism on the station's multihatch U.S. Unity module. Little bits of lubricant were spied on the mechanism during an inspection last month, and flight directors want to make certain it is clean before a docking port is moored to it in late August.

The clean-up job will be the final major task in the spacewalk, which began around 6:30 a.m. You can watch the action unfold here in The Flame Trench. Simply click on the link below the image above to launch our NASA TV viewer.

NOTE ON IMAGES: Click to enlarge the NASA screen grabs. Both show Clay Anderson at the end of the International Space Station's robot arm after he jettisoned the Early Ammonia Servicer. The top image is from the Associated Press. In the other screen grab, the coolant tank can be seen in the bottom left of the image.