ISS Flight 3A was launched aboard the Space Shuttle Discovery on STS-92.

Launch Date: October 11, 2000

The "3A" designation indicates that it is the third American flight in a planned series of flights to construct the International Space Station (ISS). The Flight 3A element consists of the Z1 Truss and the Pressurized Mating Adapter (PMA) 3 elements. Four spacewalks were required by the crew of STS-92 to complete installation of the 3A flight elements. The four Control Moment Gyro's (CMG) that control ISS attitude are mounted on the Z1 truss, though they are not scheduled for activation until the arrival of the US Labratory module on Flight 5A..