Complex sentence: The primary payload for the mission, the Wake Shield Facility, was designed to generate new semiconductor films for advanced electronics, and was flown at the end of Discoverys robotic arm over the course of the flight.
Split into simpler sentences: The primary payload for the mission was the Wake Shield Facility (or WSF), a device designed to generate new semiconductor films for advanced electronics. The WSF was flown at the end of Discoverys robotic arm over the course of the flight.