On Saturday, astronauts aboard the ISS have accomplished a 6-hour spacewalk. Before this, NASA had considered the dark matter detection instrument an inoperable one. But in the latest effort, they have attempted to repair a cosmic ray detector. Well, it is the fourth time the expedition team has stepped out in space since November. Andrew Morgan from NASA and Luca Parmitano from ESA have spent over 6 hours outside of the ISS. They have performed repairs to the AMS (Alpha Magnetic Spectrometer). It is a dark matter measuring instrument, set up in 2011, for a massive cost of $2 billion. But the device was supposed to work for only three years.
Last month, the astronauts had fitted new coolant pumps to regain consciousness of the equipment’s disabled cooling system. This time, they required to examine any leakages in the pipework. In total, there are eight coolant lines. Parmitano swiftly found a minor outflow in one of the lines and tightened up the fitting. But the effort did not solve the issue, the line still dripped. So Parmitano attempted another time before returning to the ISS. Finally, the leak was gone. Mission Control commended all to take a breath. By that time, the astronauts had accomplished half of their intentional six-hour spacewalk.
Along with checking for the leaks, the pair of astronauts had to cover the cosmic ray detector with thermal insulation. In overall, the AMS repair took four spacewalks. It has four cooling pumps. Reportedly, two out of its four cooling pumps had stopped functioning. NASA said if everything goes well, the $2 billion spectrometers could re-start its search for unattainable anti- and dark-matter. NASA has outlined the spectrometer spacewalks as the most challenging ones from repair missions of the Hubble Space Telescope. Distinct from Hubble, the spectrometer is not made for manipulation in space or orbit. Even more, it took years for the American space agency to create a restoration plan.