Astronauts aboard the International Space Station have began a spacewalk that will include getting rid of equipment that is no longer needed.
NASA spacewalker Clayton Anderson Monday will be throwing a refrigerator-size ammonia tank overboard. The tank was launched to provide spare coolant in case of a leak, but it was never needed.
Flight controllers expect the ammonia tank to orbit for about 11 months before it re-enters the Earth's atmosphere and burns up.
Anderson will also be dumping other items including camera-mounting equipment.
NASA says the items had to be discarded before a 2010 deadline for ending all space shuttle flights.
Other tasks during today's spacewalk include cleaning debris off a docking port.
