Cape, Canaveral, FL-- Spacewalking astronauts attached new pumps to a cosmic ray detector outside the International Space Station on Monday in a bid to extend its scientific life. It was the third spacewalk in nearly three weeks for Italy’s Luca Parmitano and NASA’s Andrew Morgan. And it marked the culmination of years of work to repair the $2 billion Alpha Magnetic Spectrometer. The spectrometer has been up there hunting for antimatter and dark matter for 8 ½ years, longer than anticipated. Without four new pumps for cooling, the device would be crippled and, ultimately, useless. NASA compares this series of four spacewalks - the most complex since the Hubble Space Telescope missions - to heart bypass surgery because they are designed to bypass the old, degraded pumps.