CAPE CANAVERAL, Fla. — Spacewalking astronauts ripped through thick insulation on a capsule docked to the International Space Station on Tuesday, looking for clues to a mysterious drilled hole that leaked precious cabin air four months ago. Russians Sergei Prokopyev and Oleg Kononenko spotted the tiny hole in the external hull of the Soyuz capsule, more than five hours into their grueling spacewalk. “That is exactly the hole we’ve been looking for, guys,” radioed Russian Mission Control outside Moscow. The spacewalkers reported seeing no drill marks around the black dot, like on the inside. Back in August, the station crew patched the hole in the Soyuz capsule, plugging it with epoxy and gauze.