Astronauts, who were transported in the Endeavour space shuttle to the International Space Station (ISS), have prepared for their final spacewalk today focusing on increasing the robotics capability of the station.

NASA’s Endeavour and its six crew members are set to return on June 1 finishing the final mission of the space craft. The mission involved delivery of supplies, equipment and experiments to the space station.

Endeavour crew members have already conducted three spacewalks in the last 11 days they have been at the ISS. Endeavour crew members today used the robotic arm onboard the shuttle to perform a check on vehicle's heat shield and wings.

Generally this check is done after a space shuttle undocks from the space station but as this is Endeavour's final mission, the robotic arm will be detected from the shuttle and will be attacked to the station.

The spacewalk on Friday will not only be the mission's last spacewalk but also the last spacewalk for any shuttle astronauts. The shuttle fleet's final launch will be that of Atlantis but the crewmembers are not expected to participate in any spacewalks.

NASA said that Wednesday's spacewalk brought the total time spent for station assembly construction and maintenance to 995 hours and 13 minutes during 158 spacewalks.