The mission's Development Phase ran from February 1992, through May 1996. The Submillimeter Wave Telescope underwent a preliminary design review on May 13, 1992, and a critical design review on February 23, 1993. Ball Aerospace was responsible for the construction of and integration of components into the telescope. The University of Cologne delivered the acousto-optical spectrometer to Ball for integration into the telescope on December 2, 1993, while Millitech Corporation delivered the Schottky receivers to Ball on June 20, 1994. Ball delivered the finished telescope to Goddard Space Flight Center on December 20, 1994. Goddard, which was responsible for construction of the spacecraft bus, conducted integration of spacecraft and instrument from January through March 1995. Spacecraft qualification and testing took place between April 1, 1995, and December 15, 1995. After this, SWAS was placed into storage until September 1, 1998, when launch preparation was begun.