Space Shuttle Discovery is launched on STS-120, with Pamela Melroy becoming the second female space shuttle commander.

Space Shuttle Discovery is a retired American Space Shuttle orbiter. The spaceplane was one of the orbiters from NASA's Space Shuttle program and the third of five fully operational orbiters to be built. Its first mission, STS-41-D, flew from August 30 to September 5, 1984. Over 27 years of service it launched and landed 39 times, aggregating more spaceflights than any other spacecraft as of December 2024. The Space Shuttle launch vehicle had three main components: the Space Shuttle orbiter, a single-use central fuel tank, and two reusable solid rocket boosters. Nearly 25,000 heat-resistant tiles cover the orbiter to protect it from high temperatures on re-entry.

STS-120 was a Space Shuttle mission to the International Space Station (ISS) that launched on October 23, 2007, from the Kennedy Space Center, Florida. The mission is also referred to as ISS-10A by the ISS program. STS-120 delivered the Harmony module and reconfigured a portion of the station in preparation for future assembly missions. STS-120 was flown by Space Shuttle Discovery, and was the twenty-third Space Shuttle mission to the ISS. It was Discovery's 34th flight.

Pamela Ann Melroy is an American retired United States Air Force officer and NASA astronaut serving as the deputy administrator of NASA. She served as pilot on Space Shuttle missions STS-92 and STS-112 and commanded mission STS-120 before leaving the agency in August 2009. After serving as deputy program manager of Space Exploration Initiatives with Lockheed Martin, Melroy joined the Federal Aviation Administration in 2011, where she was a senior technical advisor and director of field operations for the FAA's Office of Commercial Space Transportation.

October 23 is the 296th day of the year in the Gregorian calendar; 69 days remain until the end of the year.