CAPE CANAVERAL, Fla. (AP) — Spacewalking astronauts plugged a leak in a cosmic ray detector outside the International Space Station on Saturday, completing a series of complex repairs to give the instrument new life.

The $2 billion Alpha Magnetic Spectrometer could resume its hunt for elusive antimatter and dark matter by midweek.

Team members around the world expressed relief as NASA's Andrew Morgan and Italy's Luca Parmitano wrapped up work on the spectrometer. It was their fourth and final spacewalk since November to revive the instrument's crippled cooling system.

"Congratulations ... the...