Russians Alexander Skvortsov and Oleg Artemiev panted and sighed as they dealt with balky clamps and latches. Mission Control outside Moscow urged them to take frequent breaks.
"Resting is most important," Mission Control radioed in Russian.
Two hours into the spacewalk, the first-time spacewalkers still were struggling to secure the antenna, considered a major job. They hauled the antenna out with them, at the start of the spacewalk.
"We almost have it. Almost there," one of the astronauts said as the work dragged on.
Two of the three locks clicked into place on the antenna. But the third would not work right, and the astronauts had to use a wire tie instead. Each spacewalker tugged on the tie to tighten it. With that finally complete, the two successfully made a series of connections, eliciting a "Hurrah!"
"Slowly but surely," one of the spacewalkers said as he worked with the connectors.
Running behind schedule, Skvortsov and Artemiev moved on to their next chore. Their to-do list included moving a payload boom and switching out science experiments.
The four astronauts inside kept tabs on the 260-mile-high action, while conducting their own work.
"Pretty neat up here right now," U.S. astronaut Reid Wiseman said via Twitter. "Two Russian crew mates are spacewalking but business as usual for me and @astro_alex," he said, referring to German Alexander Gerst.
The crew includes three Russians, two Americans and the one German. The Americans are supposed to venture out on NASA-led spacewalks in August. Skvortsov and Artemiev also have another spacewalk scheduled for August.
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