List of Figures

• The Astro Observatory mounted in the shuttle
• Line drawing of HUT instrument
• Location of the hardware used to attach telescopes to IPS
• The principal elements contained within the ECC
• The HUT primary mirror
• The HUT spectrometer system
• Intensified photodiode array detector
• Display: HOP  HUT Operations
• Display: HDC  HUT doors and camera
• Display: HMH  HUT mirror and heater
• HUT Astro-1 Lyman-$\alpha$ scattering profile
• Flat field correction for the small aperture door
• Raw counts spectrum of G191-B2B
• HUT inflight/postflight calibration comparison
• Expected 2nd order effective area for Astro-2
• Expected 2nd order + Al filter effective area for Astro-2
• Extended source sensitivity for S/N = 10 per Å
• HUT airglow, 20'' aperture, Day, 1800 s