CAPE CANAVERAL: Spacewalking astronauts worked to complete repairs to a cosmic ray detector outside the International Space Station on Saturday and give it new life.

It was the fourth spacewalk since November for Nasa’s Andrew Morgan and Italy’s Luca Parmitano to fix the Alpha Magnetic Spectrometer. They installed new coolant pumps last month to revive the instrument’s crippled cooling system and needed to check for any leaks in the plumbing.

Parmitano quickly discovered a slight leak and tightened the fittings. Our day just got a little more challenging, Mission Control observed.

Provided everything goes well, the $2 billion spectrometer launched to the space station in 2011 could resume its hunt for elusive antimatter and dark matter next week, according to Nasa.

Nasa has described the spectrometer spacewalks as the most complicated since the Hubble Space Telescope repair missions a few decades ago. Unlike Hubble, this spectrometer was never intended for astronaut handling in orbit, and it took Nasa years to devise a repair plan.

Despite their complexity, the first three spacewalks went well. Morgan and Parmitano had to cut into stainless steel pipes to bypass the spectrometer’s old, degraded coolant pumps, and then spliced the tubes into the four new pumps no easy job when working in bulky gloves. The system uses carbon dioxide as the coolant.

Besides checking for leaks Saturday, the astronauts had to cover the spectrometer with thermal insulation.

Good luck out there, have a lot of fun,” astronaut Jessica Meir radioed from inside. “We are very excited for you to be finishing off all of the amazing work that you’ve already put into this AMS repair, and I think everyone’s excited to the prospects of what AMS has to offer once you guys finish off the work today.

Published in Dawn, January 26th, 2020