An American and a German astronaut spent just over six hours on a spacewalk outside the International Space Station (ISS) Tuesday for equipment repairs and maintenance, NASA said.

NASA's Reid Wiseman and the European Space Agency's Alexander Gerst left the space station at 1230 GMT and were back inside at 1843 GMT.

The astronauts completed all the scheduled repairs, NASA said on its website.

The two astronauts moved a failed cooling pump to an external storage platform just outside the Quest airlock module. Gerst then replaced a light on a television camera located on the Destiny module.

The astronauts also installed a Mobile Transporter Relay Assembly, which can shift gear and supplies on rails along the space station's backbone.

NASA's Barry Wilmore, who arrived at the ISS on September 25, was operating a Canadian robotic arm to maneuver Gerst during the spacewalk.

A second spacewalk is planned for October 15, when Wiseman and Wilmore will replace a failed voltage regulator. They will also move external camera equipment ahead of a major reconfiguration of station modules next year, NASA said in a statement.

The reconfiguration will allow for the arrival of new docking adapters for commercial crew vehicles.

Boeing and SpaceX last month won NASA contracts to build these spacecraft.

The two spacewalks are the 182nd and 183rd carried out to maintain the ISS.