Two crew members of the US space shuttle Endeavour, Mike Fincke and Greg Chamitoff floated out of the ISS early today for a spacewalk scheduled to last six-and-a-half hours. Fincke and Chamitoff will remove a 15-meter extension boom from Endeavour and install it on station's truss. Today's spacewalk is the 159th maneuver dedicated to the construction of the ISS. Endeavour will be decommissioned after it returns to Earth on Wednesday. The space shuttle Atlantis will bring an end to the shuttle programme with its final flight to the ISS in July. Endeavour crew member Mike Fincke will set a personal milestone today, when he breaks the US record of 377 days in space.