CAPE CANAVERAL, Fla. (AP) — Spacewalking astronauts have replaced a broken antenna outside the International Space Station after getting NASA’s all-clear for orbiting debris. Tom Marshburn and Kayla Barron completed the job Thursday. They were supposed to do it Tuesday, but NASA delayed their spacewalk because of potentially threatening space junk. NASA later determined the astronauts were safe to go out, despite a slightly increased risk of a punctured suit from satellite wreckage. Russia destroyed an old satellite in a missile test last month, sending pieces everywhere. NASA isn’t saying whether the object of concern was from that event. But a fragment of an old U.S. rocket is forcing the space station to lower its orbit Friday.