Reid Wiseman and Barry "Butch" Wilmore finished their spacewalk after six hours and 34 minutes, right on schedule, the US space agency said yesterday.
Their first task was to replace a suitcase-sized power regulator for a solar array that had failed in May.
The operation required some careful coordination with the time when the space station passed under Earth's shadow, so that electricity was not being generated by the solar array.
Then, the astronauts set to their next task of moving equipment to make space for international docking adapters scheduled to be delivered to the complex in 2015.
They aso replaced an external TV camera that had lost its zoom capability, and replaced it with a new one.
Yesterday's spacewalk was the 183rd at the International Space Station, but was Wilmore's first.
It was the second outing for Wiseman, who along with flight engineer Alexander Gerst of the European Space Agency completed a six-hour spacewalk on October 7.
