STS-120 was a space shuttle mission to the International Space Station (ISS) that launched on 23 October 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.
As commander of STS-120, Pamela Melroy became the second woman (after Eileen Collins) to command a space shuttle mission. Additionally, the Expedition 16 crew that received STS-120 was commanded by Peggy Whitson, the first female ISS commander. The flight of STS-120 thus became the first time two female mission commanders were in space at the same time.
Prior to the Space Shuttle Columbia disaster, the original crew manifest for STS-120 was:
The STS-120 mission patch was designed by Michael Foreman before he was reassigned to STS-123.