An astronaut is gearing up for the first spacewalk of his career while awaiting the imminent birth of his daughter.

Atlantis crewman Randolph Bresnik will step out Saturday morning to work on the International Space Station. He will be joined by Michael Foreman. It will be the second spacewalk during the shuttle's visit.

Bresnik's wife, Rebecca, is due to give birth any moment back home in Houston. They have an adopted three-year-old son.

Friday was her expected delivery date. But there was still no word early Saturday.

The spacewalk was delayed more than an hour by false decompression alarms that rang through the orbiting complex late Friday, for the second night in a row. The alarms disrupted spacewalk preparations.