On April 09, 2010 American astronauts Clayton Anderson and Richard Mastracchio performed the first of three planned spacewalks.
They configured an old Ammonia Tank Assembly (ATA) for removal and prepared a new ATA for installation. On the center-most portion of the station’s backbone, they replaced a Rate Gyro Assembly, part of the station’s navigation system.
The spacewalk lasted 6 hours and 27 minutes. Attachments: | 
