Mission STS-106 was added to the manifest after delays in launching Zvezda. The STS-101 flight was originally planned to carry cargo to the ISS and have three crew perform an EVA to connect Zvezda to the ISS, but the delays caused the mission objectives of STS-101 to be split into 2A.2a (STS-101) and 2A.2b (STS-106). The three spacewalk crewmembers Lu, Williams, and Malenchenko followed their EVA onto STS-106.
