The seven-day mission included two spacewalks to connect power and data transmission cables between the Unity Connecting Module and the Zarya Control Module. The Zarya Control Module was launched on a Russian Proton rocket from the Baikonur Cosmodrome in Kazakstan in November, 1997.
Unity was the first Space Station hardware delivered by the Space Shuttle; it has two Pressurized Mating Adapters (PMA), one attached to each end. One PMA is permanently mated to the Control Module and the other will be used for orbiter dockings and crew access to the station. The Unity Module also contains an International Standard Payload Rack that will be used to support on-orbit activities once activated after the fifth Shuttle/Station assembly flight.
To begin the assembly sequence, the crew conducted a series of rendezvous maneuvers similar to those conducted on other Shuttle missions to reach the orbiting control module. The Shuttle's robot arm was used to place Unity atop the Orbiter Docking System. The control module was then captured with the robot arm and placed on the connecting module's Pressurized Mating Adapter.
Once the two modules were docked, two spacewalks were conducted to connect power and data cables between Unity, the PMAs and Zarya. The day following the spacewalks, Endeavour undocked from the two components, completing the first Space Station assembly mission.
Detailed Supplementary Objectives (DSOs) were performed on this mission. A DSO is a NASA-sponsored investigation performed by Space Shuttle crewmembers, who serve as the test subjects. These studies are designed to require minimal crew time, power and stowage. Biomedical DSOs focus on operational concerns, including space motion sickness, cardiovascular deconditioning, muscle loss, changes in coordination and balance strategies, radiation exposure, pharmacokinetics and changes in the body's biochemistry.
Other payloads on the STS-88 mission were the IMAX Cargo Bay Camera (ICBC), the Argentinean Scientific Applications Satellite-S (SAC-A), the MightySat 1 Hitchhiker payload, the Space Experiment Module (SEM-07) and Getaway Special G-093 sponsored by the University of Michigan.
NASA's final Shuttle mission of 1998 came to an end with the landing of Space Shuttle Endeavour at Kennedy Space Center on December 15, 1997.