The Spacelab development program is a joint undertaking of the National Aeronautics and Space Administration (NASA) and the European Space Agency (ESA). The purpose of Spacelab is to include in the space transportation system (STS) a payload carrier with maximum flexibility to accommodate payloads of all scientific disciplines. The first Spacelab mission is a jointly planned mission between NASA and ESA which is currently planned for launch in June 1983. The mission is multidisciplinary in nature and has two main objectives. The first and primary objective of the flight is the verification of Spacelab performance and its interfaces with the Space Shuttle/orbiter. Second, the mission is to perform scientific investigations in a variety of science disciplines to demonstrate the broad capability of Spacelab for space research. Currently, there are 38 experiments and/or experiment facilities under development and test for flight on Mission 1. These experiments cover a variety of science disciplines including atmospheric research, life science, space plasma research, materials sciences, astronomy and technology. In addition to the experiments, the final design of the integrated payload has been completed, and the necessary integration hardware has been designed and is presently in fabrication. During the course of this paper, the current status of design and accommodation will be presented. Additionally, the planning and status of the ground and flight operations activities will be discussed. As the various elements in the planning and implementation of the mission are discussed, the paper will attempt to focus on the lessons learned to date in integrating the first Spacelab mission.