# ISS Crew Revives $2 Billion Dark Matter Detector
Written on
Chapter 1: Introduction to the Alpha Magnetic Spectrometer
A decade prior, a collaboration of NASA, CERN, and numerous institutions came together to develop the Alpha Magnetic Spectrometer (AMS), with a staggering investment of $2 billion. This sophisticated instrument has played a crucial role in the investigation of dark matter from its position on the International Space Station (ISS), yet it has faced several component failures in recent years. Originally, the AMS was not designed for repairs, but astronauts have recently managed to restore this valuable scientific apparatus through a series of spacewalks.
The AMS was delivered to the ISS in 2011 during one of the last Space Shuttle missions dedicated to cargo transport. At the time, the team did not anticipate that the instrument could be repaired while in orbit, which led to its design without maintenance capabilities. Initially expected to function for just three years, the AMS has yielded significant insights into the nature and abundance of dark matter. However, as the cooling pumps began to malfunction, space agencies decided to attempt a repair.
NASA prepared for the repair operation by sending specialized tools and replacement components to the ISS last year, anticipating that the task could require up to five spacewalks. The AMS contains four coolant pumps, but by 2019, only one was functioning when the first spacewalk occurred. In November 2019, the ISS crew successfully completed two spacewalks, followed by a third in December. Most recently, European Space Agency astronaut Luca Parmitano and NASA's Andrew Morgan finished the repair work during the fourth and final spacewalk.
Chapter 2: The Repair Process
Repairing the AMS involved installing new cooling pumps (illustrated in the image above), replacing the power and data cabling, and repressurizing the liquid carbon dioxide coolant. While most hardware tasks were completed in the preceding three spacewalks, Parmitano and Morgan needed to meticulously inspect every fitting and cable before pressurizing the new cooling system. During their inspection, they discovered a minor leak in one of the cooling lines, which they successfully fixed by tightening the connection.
Following the repairs, the ground team confirmed that preliminary tests indicate the AMS is functioning as intended. However, it is not yet ready for scientific experiments. The cooling system must operate for several additional days to stabilize the instrument's temperatures, after which the team will power it up for further testing. NASA anticipates that the AMS will be operational once again by the end of next week.
Now read: Boeing Starliner Fails Space Station Test Flight, Ends Up in Wrong Orbit. Scientists Use Spherical Flames on ISS to Understand Soot-Free Fires. Nanoparticle Experiment Aboard ISS Seeks to Slow Aging.