Scientists are still struggling to understand the puzzle of dark matter, a theoretical type of matter which holds galaxies together and is believed to comprise up to 85% of the mass of the universe. One of the best tools we have for investigating this mystery has been the Alpha Magnetic Spectrometer (AMS), an instrument installed on the outside of the International Space Station (ISS) in 2011. But the AMS was only designed to be in operation for three years, and after 2014 it began to show signs of wear and tear. Now, ISS astronauts will attempt to rejuvenate the device and get it working once again.
When first installed, the AMS cost a staggering $2 billion, but over its life, it proved its worth through a series of research papers based on the data it collected which revealed new findings about the fundamental nature of our universe. The issue with the instrument now is that over time, the cooling system which keeps delicate components at a steady temperature has stopped working. There were originally multiple redundant cooling pumps, but each one has failed until only one remained fully functional in 2017.
The problem with trying to fix the cooling system now is that the instrument was never designed to be serviceable, as it was considered too complex. Some of the challenges of fixing the instrument include a lack of foot restraints and handrails for the astronauts to hang onto while performing repairs, and the fact it was not designed to be worked on with standard spacewalk tools.
“When you put somebody in a big suit with pressurized gloves with limited dexterity, it changes the game entirely. You have to design tools and procedures completely differently,” spacewalk task lead Brian Mader explained in a statement.
Nevertheless, given the wealth of data AMS has collected over the years, not to mention its high initial cost, NASA wanted to find a way to keep the instrument going. Therefore, ISS astronauts will head outside the station and attempt to install a new cooling system and bypass the old one, which requires the cutting and reconnecting of fluid lines — something that has never been done during a spacewalk before.
The astronauts have been preparing to tackle the repairs with new training and procedures, while down on the ground, engineers have been creating new spacewalk tools like plumbing instruments to cut the cooling lines, screwdriver bits, and devices to stop unscrewed fasteners from floating away. These tools will soon be delivered to the ISS aboard a Northrop Grumman resupply ship, and the repairs will be made during a series of upcoming spacewalks over the next several months.