(AP) -- It's moving and spacewalking day in orbit.
On Tuesday afternoon, some of the 13 astronauts at the linked shuttle and station will begin unloading tons of equipment and experiments that were delivered by Discovery. The gear is inside a huge closetlike chamber that was attached to the space station Monday. One of the first items to come out will be a treadmill named after Comedy Central's Stephen Colbert.
Right around the same time, two of the crew will step out on the first spacewalk of the mission.
The space station's newest resident, Nicole Stott, will conduct the spacewalk with Danny Olivas. Together, they will remove an old ammonia tank. A new, fully loaded tank will be installed on the second spacewalk Thursday.
©2009 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.
Explore further: Mysteries of space dust revealed