Spacewalkers Start Switch of Station’s Cooling System article

This article is about how the astronauts on the space station went on a spacewalk to relocate some cooling lines to a better, more perminant location. The spacewalk took about 8 hours, which is longer than expected. This is because they needed to be more careful not to get any ammonia on themselves. That could cause contamination in the air inside the station.

To relate this to physics, the spacewalking suits are full of electrical equipment. In order to control the thrust, electric valves are used to provide the right amount of flow of the propellant. These valves are opened and closed with a flow of electrons from a power source. These electrons push a motor around, powering the valve open. If one of the electrical wires was severed, the electrons would not be able to flow to the motor.