The Scientific Objectives and Technical Details of the SPIDR

In July, 2002 NASA selected two small explorer missions for flight in 2005 and 2006. The NASA Explorer Program provides frequent, low-cost access to space for physics and astronomy missions with small to mid-sized spacecraft. The Spectroscopy and Photometry of Intergalactic medium's Diffuse Radiations (SPIDR) mission will use imaging ultraviolet spectrographs to look for the Cosmic Web - a filamentary structure of tenuous warm-hot (10⁵ - 10⁶ K) gas predicted by cosmological models. This talk will describe the scientific motivation, measurement approach and the mission design.