Boston, Mass., July 10 -- NASA announced this week that Boston University's (BU) SPIDR project has been chosen to be the next mission in the agency's Small Explorer (SMEX) program. Supriya Chakrabarti, director of BU's Center for Space Physics, is the principle investigator for the $90 million project, which will be launched in 2005. The project includes co-investigators from eight other universities and collaborators from the Draper Lab in Cambridge, Mass. SPIDR -- Spectroscopy and Photometry of the Intergalactic Medium's Diffuse Radiation -- will map the "cosmic web" of hot gas that permeates the universe. Current cosmological theory holds that gases produced by the Big Bang that brought the universe into existence condensed into a giant filamentary web along which the galaxies and clusters of galaxies eventually formed. SPIDR's findings will both test this basic understanding of the nature of the universe and provide new information upon which the understanding can be developed further. Boston University scientists will design and build the ultraviolet spectrograph on board the SPIDR satellite. SPIDR is one of two missions NASA announced it chose from 46 proposals originally submitted to NASA in February 2000. Only six SMEX missions have been launched since 1992, five of which are still operating and returning data. SPIDR is planned to have a mission lifetime of at least three years.