Spacewalking astronauts working on repairs to the $2 billion cosmic ray detector outside the International Space Station have successfully plugged a leak in the coolant system.
The spacewalk on Saturday marked the fourth since November for NASA’s Andrew Morgan and Italian astronaut Luca Parmitano.
Their recent forays into space are part of a broader effort to fix the 7-ton Alpha Magnetic Spectrometer, which was launched to the space station in 2011.
The astronauts in December installed new coolant pumps on the instrument, but Parmitano quickly discovered a leak Saturday morning in one of the eight recently-added lines.
“Our day just got a little more challenging,” Mission Control noted.
Parmitano tried to tighten and refit the line, but it continued to leak after the one-hour mandatory wait time. When the astronaut again tried to tighten the coolant line, the leak finally stopped, allowing for a collective sigh of relief.
By that time, Morgan and Parmitano were already three hours into their planned six-hour spacewalk, which kicked off just after 7 a.m.
Despite a successful resolve, Mission Control said the leak resulted in some unwanted “drama.”
“Everybody’s hearts stopped,” Mission Control said.
In addition to checking for leaks, astronauts also planned to cover the spectrometer with insulation on Saturday.