Second Generation Spectrograph For The Hubble Space Telescope

We present the preliminary design for the Space Telescope Imaging Spectrograph (STIS), which has been selected by NASA for definition study for future flight as a second generation instrument on the Hubble Space Telescope (HST). STIS is a 2-dimensional spectrograph that will operate from 1050A-11000A at the limiting HST resolution of 0.05 arcsec FWHM, with spectral resolutions of 100, 1200, 20,000, and 100,000 and a maximum field-of-view of 50X50 arcsec. Its basic operating modes include echelle mode (like IUE), long slit mode (for simultaneous spectra at 1000 positions on the target), slitless spectrograph mode, coronographic spectroscopy, photon time-tagging and direct imaging. Photon counting MAMA detectors are used in the UV, while large format cooled CCDs are the visible and near-IR detectors. Research objectives are active galactic nuclei, the intergalactic medium, global properties of galaxies, the origin of stellar systems, stellar spectral variability, and spectrographic mapping of solar system processes.