A spacewalk has begun on the international space station.
    
The walk started late over concerns about high carbon dioxide levels in redesigned Russian space suits.
    
High concentrations of the gas can cause dizziness, nausea and other problems.
    
But the two space walkers said they felt fine, and ground controllers decided the levels were not a threat.
    
A veteran Russian cosmonaut and rookie U.S. astronaut are making the walk to install a docking port.