Astronauts onboard the space shuttle Endeavour have completed the first spacewalk of the STS-123 mission.

Nasa Mission Specialist Rick Linnehan and Flight Engineer Garrett Reisman took seven hours and one minute to install a part of the Japan's Kibo laboratory on the International Space Station (ISS).

A statement on Nasa's website said the astronauts had successfully completed the first of five spacewalks during the shuttle's 16-day mission.

MS Linnehan and FE Reisman's spacewalk coincided with a robotic arm moving other parts of the Japan Aerospace Exploration Agency's (JAXA) laboratory onto the ISS.

Kibo, Japan's first contribution to the ISS, will ultimately become the largest laboratory on the space station when the three shuttle missions required to transport it are completed.

Japanese officials at Nasa mission control in Houston hailed the first stage of Kibo's installation as a "memorable day for Japan's human space flight programme".

"It has been very exciting for us at JAXA to watch today's activities," Tetsuro Yokoyama, deputy manager of operations at Kibo, told reporters.

A second spacewalk is scheduled for tomorrow evening.
© Adfero Ltd