Spacewalking Astronauts Perform Repairs at International Space Station

Spacewalking astronauts ventured outside the International Space Station for the second week in a row, Friday, November 22, to repair a cosmic ray detector, this time actually cutting into the $2 billion instrument.
The International Space Station’s Luca Parmitano and Andrew Morgan needed to slice through eight stainless steel tubes, using hardware store-type bolt cutters. That will set the stage to install new coolant pumps during the third spacewalk, December 2.
NASA likens the repair work to heart bypass surgery. At least four spacewalks are needed to fix the spectrometer, which is on the hunt for elusive dark matter and antimatter for more than eight years. Without a new cooling system, the experiment, led by a Nobel laureate, would end.