STS 88 Mission Specialists Jerry L. Ross get a close look at the Orbiter Docking System.

Inside the payload bay of orbiter Endeavour in the Orbiter Processing Facility Bay 1, STS-88 Mission Specialists Jerry L. Ross (left) and James H. Newman (right foreground) get a close look at the Orbiter Docking System. The STS-88 crew members are participating in a Crew Equipment Interface Test (CEIT), familiarizing themselves with the orbiter's midbody and crew compartments. Targeted for liftoff on Dec. 3, 1998, STS-88 will be the first Space Shuttle launch for assembly of the International Space Station (ISS). The primary payload is the Unity connecting module which will be mated to the Russian-built Zarya control module, expected to be already on orbit after a November launch from Russia. While on orbit during STS-88, Unity will be latched atop the Orbiter Docking System in the forward section of Endeavour's payload bay for the mating of the two modules. After the mating, Ross and Newman are scheduled to perform three spacewalks to connect power, data and utility lines and install exterior equipment. The first major U.S.-built component of ISS, Unity will serve as a connecting passageway to living and working areas of the space station. Unity has two attached pressurized mating adapters (PMAs) and one stowage rack installed inside. PMA-1 provides the permanent connection point between Unity and Zarya; PMA-2 will serve as a Space Shuttle docking port. Zarya is a self-supporting active vehicle, providing propulsive control capability and power during the early assembly stages. It also has fuel storage capability